Section 6-02 applies to the construction of all Structures (and their parts) made of Portland cement concrete with or without reinforcement. Any part of a Structure to be made of other Materials shall be built as required elsewhere in the Standard Specifications.

Materials shall meet the requirements of the following Sections:

Portland Cement	9-01
Aggregates for Portland Cement Concrete and Gravel Backfill	9-03
Joint and Crack Sealing Materials	9-04
Reinforcing Steel	9-07
Epoxy-Coated Reinforcing Steel	9-07
Prestressed Concrete Girders	9-19
Concrete Curing Materials, Admixtures, and Mixes Incorporating Fly Ash	9-23
Plastic Waterstop	9-24
Water	9-25
Elastomeric Bearing Pads	9-35

Bridge drains shall comply with Section 6-02.3(36). Downspouts shall comply with Section 6-02.3(29).

Unless specified otherwise in the Contract, the Contractor shall use Type II Portland cement in all concrete. The mix to be used in various parts of the Structure will be specified in the Contract. Unless the Contract specifies otherwise, the following applies:

Class Of Concrete	Use
AX	Thin and heavily reinforced members; in all roadway slabs subject to abrasive action of Traffic; in all cast-in-place beams and girders; in all traffic barriers, columns, arch ribs and arch rings; in approach slabs.
B	All reinforced sections other than those covered by Class AX.
C	Unreinforced sections of footing blocks, heavy walls, and other mass construction.
D, DX	Areas where concrete is to be deposited under water, such as seals.
LS	Areas where shrinkage must be reduced, such as closure pours.

The Contractor may request substituting a class of concrete with a higher than specified 28-day design strength. Any request for a substitution shall be submitted at least 10 Working Days before the need arises and will be evaluated for acceptance based on the class of concrete specified. No separate or additional payment will be made resulting from this substitution.

The 28-day design strength for each class of concrete listed in Section 6-02.3(1) is shown in the table that follows. The Contractor shall use as little water as possible for acceptable placement and shall not exceed the amounts shown in the following table. The following table also provides a guideline for concrete mixes, assuming a bulk specific gravity of 2.67 for each size of aggregate. The weight shown for each size of aggregate is only an estimate of the amount to be used per cubic yard of concrete. Actual amounts may vary from those shown, because the Engineer may adjust the mix to correct for actual bulk specific gravity or moisture content or both, or to ensure proper consistency, workability, correct cement content, and yield.

Class of Concrete	A	B	C	D	DX	AX	LS1
Compressive strength, psi	3,600	3,000	2,300	3,600	3,600	4,000	4,000
Max. gals. of mixing Water per 100 lbs. of Portland cement	5.33	6.15	7.23	5.33	5.33	5.30	4.55
Lbs. of cement per cubic yd.	610	540	470	610	610	660	660
Lbs. of SSD Class 2 Fine aggregate	1,395	1,470	1,375	1,195	1,300	1,420	1,420
Lbs. of SSD Grading No. 2 Coarse aggregate	1,860	1,820	1,970	2,060	---	---	---
Lbs. of SSD Grading No. 5 Coarse aggregate	---	---	---	---	1,955	1,735	1,735

Proportions are by Weight.

1Water-reducing admixture shall be used in Class LS concrete as outlined in Section 6-02.3(3)B.

The total chloride ion (Cl-) content of the mixed concrete shall not exceed 0.06 percent of cementitious material for prestressed concrete nor 0.10 percent of cementitious material for reinforced concrete (see exception in Section 6-02.3(3)B). Cementitious material shall be the weight of cement plus fly ash, and microsilica, if used.

Concrete for bridge decks, bridge approach slabs, and for Engineer provided mixes shall use only Class 1 fine aggregate. Concrete for slip-formed barrier may use Class 1 or Class2 fine aggregate.

Unless otherwise specifiedin the Contract, the Contractor shall use Type II Portland cement in all concrete.

The Contractor may propose the use of fly ash for all classes of concrete other than for Owner-provided mixes. The Contractor shall submit the proposed mix design incorporating fly ash along witha Manufacturer's Certificate of Compliance indicating the mix design meets or exceeds the specified requirements. Fly ash, if used, shall not exceed 15 percent by weight of the total cementitious material in the concrete mix and all concrete within a class in a structure shall have the same proportion of fly ash. The water/cement ratio shall be calculated on the total cementitious material.

As an alternative to the use of cement and fly ash as separate components, a blended hydraulic cement, Type IP(MS) or Type I (PM) (MS), may be used. The blended cement shall be produced such that the maximum fly ash content of the cementitious material is 15 percent.

All materials that make up a batch of concrete will be measured by weight on scales that comply with Section 1-09.2.

The cement, the fine aggregate, and each size of coarse aggregate shall be weighed separately, the weight for each being proportional to its bulk specific gravity. The Engineer may correct the weight to adjust for free water held by the aggregate.

The volume in cubic feet shall equal the total batch weight (the weight, in pounds, of all materials including water) divided by the unit weight of the concrete in pounds per cubic foot. The unit weight of concrete will be determined by WSDOT Test Method 806.

If the Engineer approves, the Contractor may use mobile mixers that measure material by volume.

Concrete admixtures shall be added to the concrete mix at the time of batching the concrete, or in accordance with the manufacturer’s written procedure as approved by the Engineer. A copy of the manufacturer’s written procedure shall be furnished to the Engineer prior to use of any admixture. Admixtures from different manufacturers shall not be used together unless the Contractor provides written documentation verifying that the admixtures are compatible in combination with all other ingredients of the concrete. Any modifications from the manufacturer’s written procedures shall be submitted with written justification for the Engineer’s approval (see Section 6-02.3(3)B). Admixtures shall not be added to the concrete with the modified procedures until the Engineer has approved them.

In all cast-in-place concrete placed above the finished ground line, the Contractor’s concrete shall have between 4.5% minimum and 6.5% maximum air entrainment. The Engineer will approvethe exact percentage of air to be entrained.

The Contractor may elect to use air entrainment for concrete placed below finished ground line. With or without air entrainment, the 28-day compressive strength of all concrete shall meet the strength requirements of the class of concrete specified.

Concrete used in all underwater placement for shafts, bridge roadway slabs, traffic and pedestrian barriers, and all Class LS concrete shall include a water-reducing admixture that conforms to AASHTO M 194, Type A.

If temperature of the surrounding air exceeds 80°F, the Contractor may use a combination of water-reducer and retardant admixture that conforms to AASHTO M 194, Type D. In this case, the chloride ionin the mixture shall conform with Section 9-23.6 of the Standard Specifications and shall be approved by the Engineer. The Engineer may require that the SPU Materials Laboratory sample and test the mixture before use.

The Contractor shall add water-reducer at the manufacturer’s recommended rate and as the Engineer may direct. The water-reducer shall be added as a liquid through an automatic dispenser approved by the Engineer. This dispenser shall inject the reducer into the first 75 percent of the mixing water that enters the batch.

Water-reducing and air-entraining admixtures shall be compatible and shall be from the same source and manufacturer. Water-reducing and air-entraining admixtures not from the same source and manufacturer require the Contractor to submit to the Engineer certified test reports stating that the two admixtures are compatible.

Non-shrink cement sand grout shall be used where indicated in the Contract. Non-shrink grout shall conform to the requirements outlined in Section 9-04.3(2).

Prior to placing the grout, the contact surface shall be thoroughly cleaned, roughened and wetted with water. The grout shall be covered with burlap sacks after the initial concrete set and wetted at regular intervals until the required strength is obtained.

All concrete shall be mixed thoroughly in a batch mixer that:

To prepare the mixer, the Contractor shall first place enough sand, cement, and water in the drum to coat its inside surface with cement mortar.

Batches shall be proportioned on the basis of pounds of cement. For each batch, some water shall enter the drum before any cement or aggregate. All water shall be added by the end of the first one-fourth of the required mixing time. Heated water used in cold weather may require the Contractor to adjust this waterto prevent flash setting. The Engineer will determine the amount of water required for each batch.

The entire batch shall be removed from the drum before materials for the next batch are added. If mixing stops long enough that the concrete shows signs of hardening, the mixer shall be thoroughly cleaned.

Concrete shall be mixed for at least 1 minute after all materials and water are in the drum; however, concrete Class D and Class DX shall be mixed 1-1/2 minutes. The Engineer may permit a shorter mixing time for special mixers if tests show equal or better results.

During mixing, the drum shall rotate within its designed speed range. This speed should not be less than 175 nor more than 225 feet per minute at the sides of the drum, and not less than 14 nor more than 20 rpm.

The Contractor shall use a device to measure and control the amount of water used in each batch. This device shall control flow to an accuracy of (1/2 percent. It shall include an easy to read gauge that is clearly visible at all times.

The Contractor shall not hand-mix concrete except in emergencies and then only with written permission from the Engineer. Hand-mixing is never permitted for concrete to be placed in water.

If the Engineer permits, hand-mixing shall be done on a watertight platform in a way that distributes materials evenly throughout the mass. Mixing shall continue long enough to produce a uniform mixture. No hand-mixed batch shall exceed 1/2 cubic yard.

Ready-mixed concrete may be used after the Engineer has inspected and approved the plant and delivery system. Approval will be given if the Supplier can produce and deliver concrete that conforms to all Owner and Engineer requirements. The delivery rate shall provide for placing of the concrete as required in Section 6-02.3(6). Delivery and handling methods shall also permit placement with a minimum of rehandling and without damage to the structure or the concrete.

The central ready mix plant shall meet the requirements of ASTM C 94. In general, the batching plant shall include bins, weighing hoppers, and scales for the fine aggregates and each size of coarse aggregate. If cement is used in bulk, a bin, hopper and separate scale for cement shall also be included. The weighing hoppers shall be properly sealed and vented to preclude dusting during operation. The batching plant shall be equipped with a suitable non-resettable batch counter which correctly indicates the number of batches proportioned during a day. Bins and hoppers shall have separate compartments of adequate size for the fine, and for each size of coarse aggregate. Scales shall meet the requirements of Section 1-09.2. Plants shall be equipped to proportion aggregates and bulk cement by means of automatic weighing devices of an approved type.

An approved Supplier may use any cement after obtaining a Manufacturer's Certificate of Compliance statingthat the cement meets all the requirements of these Specifications. The Supplier shall store this cement separately so that it may be easily distinguished from all other cement.

The Supplier may use one or more of the following methods for mixing and delivering ready-mixed concrete:

A clearly visible metal plate (or plates) attached to each mixer and agitator shall display: (1) the concrete-volume capacity of the drum or container, and (2) the rotation speed of the drum or blades. Mixers and agitators shall always operate within capacity and speed-of-rotation limits set by the manufacturers. Any mixer, when fully loaded, shall mix the ingredients into a uniform mass within the required time. Any agitator, when fully loaded, shall keep the concrete uniformly mixed. All mixers and agitators shall empty the concrete at a steady rate.

Any stationary mixer shall have a timer that prevents the batch from discharging until a set mixing time has elapsed. In shrink-mixing, the batch may be discharged from the stationary mixer as soon as the ingredients have been thoroughly intermingled (about 30 seconds).

If a truck mixer or agitator transports the concrete, the batch shall be discharged at the site no more than 1-1/2 hours after the cement enters the mix. The temperature of the concrete being placed shall be less than 75°F. When conditions are such that the concrete may experience an accelerated initial set, a shorter time to discharge may be required. When conditions would speed stiffening of the concrete, the Engineer may require a shorter delivery time. The Engineer may extend this time limit if the concrete is used for fence post foundations, so long as the mix remaining after the 1-1/2 hour limit remains usable without adding water.

In transit-mixing, mixing shall begin within 30 minutes after the cement is added to the aggregates.

Each truck mixer or agitator shall have a nonresettable counter to record the number of revolutions of its drum, blades, or paddles. In transit- or shrink-mixing, each batch shall be mixed at least 70, but not more than 100, revolutions of the drum or blades at the mixing speed designated by the equipment manufacturer. Any additional mixing shall proceed at the manufacturer’s designated agitating speed.

Any concrete transported by truck mixer or agitator shall not undergo more than 250 revolutions of the drum or blades before pouring. The Inspector shall monitor all mixing done at a plant or job site. At least once each day the Inspector shall examine mixers and agitators to find any build-ups of hardened mix or worn blades. If this examination reveals a problem, or if the Inspector wishes to test the quality of the concrete, slump tests may be performed with samples taken at approximately the 1/4 and 3/4 points as the batch is discharged. If the two slumps differ by more than 2 inches, the equipment shall not be used until the condition is corrected. However, the equipment may continue in use if longer mixing times or smaller loads produce batches that pass the slump tests.

Concrete shall be mixed only in such quantities as are required for immediate use and shall be used while fresh before initial set has taken place. Any concrete having initial set before placing and finishing shall be wasted and not used for the Work. Retempering of concrete (re-mixing with water or other materials) will not be allowed.

The maximum slump for vibrated concrete shall be:

The maximum slump for nonvibrated concrete shall be 7 inches.

The maximum slump for Class DX concrete, for underwater placement, shall be 7 inches.

When a high-range water reducer is used, the maximum slump limit may be increased an additional two inches while the concrete is affected by the admixture.

If the Contractor is unable to provide a concrete with a workable consistency, a water reducing admixture in the specified mixes may be used provided the batch meets the consistency limits of this Section and complies with the acceptance criteria specified in Section 6-02.3(5).

Aggregate weights shall conform within ± 2 percent of the weights for coarse or fine aggregate required by the mix design. The total cementitious material weight shall conform within ± 1 percent of the mix design weight. If the total cementitious material weight is made up of different components, these component weights shall be within the following tolerances:

Water measured by volume or weight shall conform within ± 1.5 percent of the mix design amount but shall, in no case, exceed the maximum water specified in the Owner provided mix design.

All weights shall conform to the mix design weights or as modified in accordance with Section 6-02.3(2)B.

The concrete producer shall provide a Manufacturer’s Certificate of Compliance for each truckload of concrete. The Manufacturer's Certificate of Compliance shall verify that the delivered concrete is in compliance with the mix design and shall include:

Manufacturer Plant (Batching Facility)

Owner Contract No.

Date

Time Batched

Truck No.

Initial Revolution Counter Reading

Quantity (Quantity batched this load)

Type of concrete by class and producer design mix number

Cement Producer, Type, and Mill Certification No. (The mill test number as required by Section 9-01.3 is the basis for acceptance of cement.)

Fly Ash (if used) Brand and Type

Approved aggregate gradation designation

Mix Design weights per cubic yard and actual batched weights for:

Cement

Fly Ash (if used)

Coarse Concrete Aggregate and moisture content (each size)

Fine Concrete Aggregate and moisture content

Water (including free moisture in aggregates)

Admixtures brand, quantity per/100 wt., and total quantity batched

Air-Entraining Admixture

Water Reducing Admixture

Other Admixture

The Manufacturer's Certificate of Compliance shall be signed by a responsible representative of the concrete producer, other than the driver, affirming the accuracy of the information provided.

The Contractor shall not place concrete:

When a foundation excavation contains water, the Contractor shall pump it dry before placing concrete. If this is impossible, an underwater concrete seal shall be placed that complies with Section 6-02.3(6)C. This seal shall be thick enough to resist any uplift.

All foundations and forms shall be moistened with water just before the concrete is placed. Any puddled water on the foundation or in the form shall be removed.

The Contractor shall place concrete in the forms as soon as possible after mixing. The concrete shall always be plastic and workable. The time todischarge may need to be reduced to meet this condition. Concrete placement shall be continuous, with no interruption longer than 20 minutes between adjoining layers unless the Engineer approves a longer time. Each layer shall be placed and consolidated before the preceding layer takes initial set. After initial set, the forms shall not be jarred, and projecting ends of reinforcing bars shall not be disturbed.

In girders or walls, concrete shall be placed in continuous, horizontal layers 1-1/2 to 2-feet deep. Compaction shall leave no line of separation between layers. The concrete shall be deposited as near its final position as possible.

Any method for placing and consolidating shall not segregate aggregates or displace reinforcing steel. Any method shall leave a compact, dense, and impervious concrete with smooth faces on exposed surfaces. Plastering is not permitted. The Contractor shall remove and replaceany defective concreteat no additional cost to the Owner.

To prevent aggregates from separating, the length of any conveyor belt used to transport concrete shall not exceed 300 feet. If the concrete mix on the belt needs protection from sun or rain, the Contractor shall cover the belt. Concrete pump operator(s) shall be certified by the American Concrete Pumping Association for the type of Equipment and class of concrete to be placed. Prior to use on the first placement of each day, a Contractor’s representative shall visually inspect the pumps water chamber for water leakage. A pump that allows free water to flow past the piston shall not be used.

If a concrete pump is used, the pump priming slurry shall be discarded before placementof concrete. Initial acceptance testing may be delayed until the pump priming slurry has been purged from the concrete being pumped. Purging the priming slurry from the concrete may require that several cubic yards of concrete be discharged through the pumping system and acceptablydisposed. When usinga concrete pump, backup equipment may be requiredat the site in case of concrete pumpbreakdowns.

If the concrete is to drop more than 5 feet, it shall be deposited through a sheet metal (or other approvedmaterial) conduit. If the form slopes, the concrete shall be lowered through theapproved conduit to keep it from sliding down one side of the form. No aluminum conduits or tremies shall be used to pump or place concrete.

Before placing concrete for roadway slabs on steel spans, the Contractor shall release the falsework under the bridge and let the span swing free on its supports. Concrete in flat slab bridges shall be placed in one continuous operation for each span or series of continuous spans.

Concrete for roadway slabs and the stems of T-beams or box-girders shall be placed in separate operations if the stem of the beam or girder is more than 3-feet deep. First the beam or girder stem shall be filled to the bottom of the slab fillets. Roadway slab concrete shall not be placed until enough time has passed to permit the earlier concrete to shrink (at least 12 hours). If stem depth is 3 feet or less, the Contractor may place concrete in one continuous operation if the Engineer approves.

Concrete placed between expansion or construction jointsshall be placed in a continuous operation.

No traffic or pedestrian barrier shall be placed until after the roadway and sidewalk slabs are complete for the entire structure. No concrete barriers shall be placed until the falsework has been released and the span supports itself. No barrier, curb, or sidewalk shall be poured on steel or prestressed concrete girder bridges until the roadway slab reaches a compressive strength of at least 3,000 psi.

The Contractor may construct traffic and pedestrian barriers by the slipform method. However, the barrier shall not deviate more than 1/4 inch when measured by a 10-foot straightedge held longitudinally on the front face, back face, and top surface. Electrical conduit within the barrier shall be constructed in accordance with the requirement of Section 8-33.3(2) (see Section 6-02.3(37)).

Electrical as-built drawings: See Sections 6-02.3(37) and 8-33.3(2)A for as-built drawing requirements of electrical conduit within concrete Structures before placing the concrete.

When placing concrete in arch rings, the Contractor shall ensure that the load on the falsework remains symmetrical and uniform.

Arch ribs in open spandrel arches shall be placed in sections. Small key sections between large sections shall be filled after the large sections have shrunk.

HOT WEATHER PROTECTION The Contractor shall provide concrete within the specified temperature limits by:

If the concrete would probably exceed 90°F using normal methods, the Engineer may require approved temperature-reduction measures be taken before the placement begins.

If air temperature exceeds 90°F, the Contractor shall use water spray or other approved methods to cool all concrete-contact surfaces to less than 90°F. These surfaces include forms, reinforcing steel, steel beam flanges, and any others that touch the mix. Water-reducing admixtures shall be used to ensure compliance with slump and water quantity requirements. The Contractor shall reduce the time between mixing and placing to a minimum and shall not permit mixer trucks to remain in the sun while waiting to discharge concrete. Chutes, conveyors, and pump lines shall be shaded.

If bridge roadway slabs are placed while air temperature exceeds 90°F, the Contractor shall employ one or more methods which include but are not limited to:

If the evaporation rate at the concreting site is 0.20 pounds per square foot of surface per hour or more (determined from Table 6-02.3(6)-1), the Contractor shall surround the fresh concrete with an enclosure. This enclosure shall protect the concrete from wind blowing across its surface until the curing compound is applied. If casting deck concrete that is 80°F or hotter, the Contractor shall install approved Equipment at the site of concrete placementto show relative humidity and wind velocity.

Table 6-02.3(6)-1 Surface Evaporation from Concrete

COLD WEATHER PROTECTION

The Contractor assumes all risks connected with the placing of concrete during cold weather. The Contractor shall submita written procedure of cold weather concreting to the Engineer at least 5 Working Days in advance. The submitted written procedurewill in no way ensure acceptance of the Work by the Owner. Should the concrete placed under the written procedureprove unacceptablein any way, the Engineer has the right to reject the concretework.

The Engineer may require the Contractor to provide and maintain a recording thermometer near the concreting sitethat is readily accessible to the Engineer. The Contractor shall not mix nor place concrete while the air temperature is below 35°F, unless the water or aggregates (or both) are heated to at least 70°F. The temperature of theaggregate shall not exceed 150°F. Water thatis heated to more than 150°F shall be mixed with the aggregates before the cement is added. Heating Equipment and methods usedshall heat the materials evenly and shall not alter or prevent the required amount of air entrainment.

The Contractor may warm stockpiled aggregates with dry heat or steam. Applying flame directly to aggregateorto containers of aggregate shall not be used. If the aggregates are in bins, steam or water coils or other heating methods may be used if aggregate quality is not affected. Live steam heating is not permitted on or through aggregates in bins. If using dry heat, the Contractor shall increase mixing time to permit the aggregates to absorb moisture.

Concrete placed in ambientair temperatures below 35°F shall be immediately surrounded with a heated enclosure. The air within the enclosure shall be maintained at a temperature between 50(F and 90°F with the relative humidity maintained above 80 percent. These conditions shall be maintained for a minimum of 7 days or for the cure period required by Section 6-02.3(11), whichever is longer. The Contractor shall stop adding moisture 24 hours before removal ofthe heatsource. Extra protection shall be provided for areas especially vulnerable to freezing (such as exposed top surfaces, corners and edges, thin sections, and concrete placed into steel forms).

If weather forecasts predict air temperatures below 35°F during the 7 days just after the concrete placement, the Contractor may place the concrete only if it is protected by surrounding with a heated enclosure.

If the Contract requires a concrete seal, the Contractor shall place the concrete underwater inside a watertight cofferdam, tube, or caisson. Seal concrete shall be placed in a compact mass and shall be placed in still water. It shall remain undisturbed and in still water until fully set. While seal concrete is being deposited, water elevation inside and outside the cofferdam shall remain equal to prevent any flow through the seal. The cofferdam shall be vented at the vent elevation shown on the Drawings. The thickness of the seal is based upon this vent elevation.

The seal shall be at least 18 inches thick unless the Contract indicates otherwise. The Engineer may change the seal thickness during construction which may require redesign of the footing and the pier shaft or column. Seal thickness changes directed by the Engineer may result in the use of more or less concrete, reinforcing steel, and excavation, and will be addressed per Section 1-04.4.

To place seal concrete underwater, the Contractor shall use a concrete pump or tremie. The tremie shall have a hopper at the top that empties into a watertight tube at least 10 inches in diameter. The discharge end of the tube on the tremie or concrete pump shall include a device to seal out water while the tube is first filled with concrete. Tube supports shall permit the discharge end to move freely across the entire work area and to drop rapidly to slow or stop the flow. One tremie may be used to concrete an area with a maximum linear dimension of18 feet any side. Each additional area of this size requires one additional tremie.

Throughout the underwater concrete placement operation, the discharge end of the tube shall remain submerged in the concrete and the tube shall always contain enough concrete to prevent water from entering. The concrete placement shall be continuous until the foundation seal concretework is completed, resulting in a seamless, uniform seal. If the concreting operation is interrupted, the Engineer may require the Contractor to prove by core drilling or other tests that the seal contains no voids or horizontal joints. If core drilling or othertesting reveals voids or joints, the concrete foundation sealwork will be considered defective and the Contractor shall repair or replace the seal, at no additional or separate cost to the Owner.

Concrete placed under water shall be Class D or Class DX mix and shall be proportioned to comply with the consistency requirement of Section 6-02.3(4)E.

After a concrete seal is constructed, the Contractor shall pump the water out of the cofferdam and place the rest of the concrete in the dry. This pumping shall not begin until the seal has set enough to withstand the hydrostatic pressure - normally at least 3 days for gravity seals and at least 10 days for seals containing piles. The Engineer may extend these waiting periods to ensure structural safety or to meet a condition of the operating permit.

If weighted cribs are used to resist hydrostatic pressure at the bottom of the seal, the Contractor shall anchor them to the foundation seal. Any method used, such as dowels or keys, shall transfer the entire weight of the crib to the seal.

No pumping shall be done during, or for 24 hours after, concrete placement unless done from a suitable sump separated from the concrete work by a watertight wall. Pumping shall be done in a way that no concrete is carried away.

Determination of concrete properties for acceptance will be made based on samples taken to most nearly represent the condition of the concrete as placed in the forms. Any placement system which, in operation, alters the specified properties of the concrete will require sampling at the discharge from the placement system. Acceptance of concrete placed through a tremie system depends on testing of concrete samples taken from the truck discharge.

It shall be the Contractor’s responsibility to provide adequate and representative samples of the fresh concrete to a location designated by the Engineer for the testing of concrete properties and making of cylinder specimens. Samples shall be provided asspecified in Section 1-06.

When mutually agreeable to the Owner and the Contractor, samples may be taken at a location other than the point of discharge. The alteration of concrete properties in passage through the placement system shall be recognized in analyzing results of such samples and in determining acceptance of the fresh concrete.

If sea water is to come in contact with a concrete Structure, the Contractor shall:

The Engineer shall decide the range of disintegration possible by exposure to sea water. This range shall extend from a point below the level of extreme low tide up to a point above the level of extreme high tide. Wave action and other conditions will also affect the Engineer’s decision on this range. The Contractor shall not locate construction joints within this range. All concrete within this range shall be poured in the dry.

The requirements for concrete in sea water shall also apply to concrete in alkaline soils or water. In addition, the Contractor shall:

The Contractor shall supply enough vibrators to consolidate the concrete(except concrete placed underwater) according to the requirements of this Section. Each vibratorshall:

Immediately after concrete is placed, vibration shall be applied in the fresh concreteat the point of deposit. The Contractor shall:

When vibrating and finishing top surfaces that are to be exposed to weather or wear, the Contractor shall not draw water or laitance to the surface. In high lifts, the top layer shall be shallow and made up of a concrete mix as stiff as can be effectively vibrated and finished.

To produce a smooth, dense finish on outside surfaces, the Contractor shall hand tamp the concrete.

A preconcreting conference shall be held 5 to 10 Working Days prior to placing concrete to discuss construction procedures, personnel, and Equipment to be used. Those attending shall include:

If the Project includes more than one slab, and if the Contractor’s key personnel change between concreting operations, an additional conference shall be held just before each slab is placed.

The Contractor shall not place roadway slabs until the Engineer agrees that:

The finishing machine shall be self-propelled and be capable of forward and reverse movement under positive control. The finishing machine shall be equipped with a rotating cylindrical single or double drum screed not exceeding 60 inches in length. The finishing machine shall have the necessary adjustments to produce the required cross-section, line, and grade. Provisions shall be made for the raising and lowering of all screeds under positive control. The upper vertical limit of screed travel shall permit the screed to clear the finished concrete surface. When placing concrete abutting a previously placed slab, the side of the finishing machine adjacent to the existing slab shall be equipped to travel on the existing slab. If performance is not acceptable, the Engineer may reject the equipment, any concrete already placed, or both.

The Contractor may use hand-operated strike-boards only for special conditions and for small areas (less than 10 feet in width and 200 feet in length) only when the Engineer approves. These boards shall be sturdy and able to strike off the width of a full roadway lane without intermediate screeds. Strike-boards, screed rails, and any specially made auxiliary equipment shall receive the Engineer’s approval before use. All finishing requirements in these Specifications apply to hand-operated finishing equipment.

Screed rails shall rest on adjustable supports that can be removed with the least possible disturbance to the screeded concrete. The supports shall rest on structural members or on forms rigid enough to resist deflection. Supports shall be removable to at least 2 inches below the finished surface. If possible, the Contractor shall place screeds outside the finishing area. However, if they are placed inside the area, they shall be placed above the finished surface.

Screed rails (with their supports) shall be strong enough and stiff enough to permit the finishing machine to operate effectively on them. All screed rails shall be placed and secured for the full length of the slab before the concreting begins. If the Engineer approves in advance, the Contractor may move rails ahead onto previously set supports while concreting progresses. But such movable rails and their supports shall not change the set elevation of the screed.

On steel truss and girder spans, screed rails and bulkheads may be placed directly on transverse steel floorbeams, with the strike-board moving at right angles to the centerline of the Roadway.

Before any concrete is placed, the finishing machine shall be operated over the entire length of the slab to check screed deflection. Concrete placement may begin only if the Engineer gives approval of screed deflection based on this test.

Immediately before placing concrete, the Contractor shall check (and adjust if necessary) all falsework and wedges to minimize settlement and deflection from the added weight of the concrete slab. The Contractor shall also install devices, such as telltales, by which the Engineer can readily measure settlement and deflection.

The Contractor shall schedule the concrete placement so that it can be completely finished during daylight. When the remaining daylight has diminished to limit adequate visibility,, finishing is permitted if the Contractor provides adequate lighting and the Engineer approves the adequacy of the lighting.

The placement operation shall cover the full width of the roadway or the full width between construction joints. The Contractor shall locate any construction joint over a beam or web that can support the slab on either side of the joint. The joint shall not occur over a pier unless the Contract permits. Each joint shall be formed vertically and in true alignment. The Contractor shall not release falsework or wedges supporting pours on either side of a joint until each side has aged as these Specifications require.

Placement of concrete for slabs shall comply with Section 6-02.3(6)A. The Engineer shall approve the placement method. In placing the concrete, the Contractor shall:

Workers shall complete all post screeding operations without walking on the concrete. This may require work bridges spanning the full width of the slab.

After removing the screed supports, the Contractor shall fill the voids with concrete (not mortar).

The Contractor shall float the concrete surface left by the finishing machine to remove roughness, minor irregularities, and seal the surface of the concrete. Floating shall leave a smooth and even surface. The floats shall be at least 4 feet long. Each transverse pass of the float shall overlap the previous pass by at least half the length of the float. The first floating shall be at right angles to the strike-off. The second floating shall be at right angles to the centerline of the span. A smooth riding surface shall be maintained across construction joints.

Expansion joints shall be finished with a 1/2 inch radius edger.

After floating, but while the concrete remains plastic, the Contractor shall test the entire slab for flatness (allowing for crown, camber, and vertical curvature). The testing shall be done with a 10-foot straightedge held on the surface. The straightedge shall be advanced in successive positions parallel to the centerline, moving not more than one-half the length of the straightedge each time it advances. This procedure shall be repeated with the straightedge held perpendicular to the centerline. An acceptable surface shall be one free from deviations of more than 1/8 inch under the 10-foot straightedge.

If the test reveals depressions, the Contractor shall fill them with freshly mixed concrete, strike off, consolidate, and refinish them. High areas shall be cut down and refinished. Re-testing and refinishing shall continue until an acceptable, deviation free surface is produced. The hardened concrete shall meet all smoothness requirements of these Specifications even though the tests require corrective work.

The Contractor shall texture the bridge deck by combing the final surface perpendicular to the centerline. Made of a single row of metal tines, the comb shall leave striations in the fresh concrete approximately 3/16-inch deep by 1/8-inch wide and spaced approximately 1/2 inch apart. The Engineer will decide actual depths at the site. (If the comb has not been approved, the Contractor shall obtain the Engineer’s approval by demonstrating it on a test section.)

The Contractor may operate the combs manually or mechanically, either singly or with several placed end to end. The timing and method used shall produce the required texture without displacing larger particles of aggregate. Texturing shall end 2 feet from curb lines. This 2-foot untextured strip shall be hand finished with a steel trowel.

If the Contract calls for an overlay (to be constructed on the same Contract) such as asphalt concrete, latex modified concrete, epoxy concrete, or similar, the Contractor shall produce the final finish by dragging a strip of damp, seamless burlap lengthwise over the full width of the slab or by brooming it lightly. A burlap drag shall equal the slab in width. Approximately 3 feet of the drag shall contact the surface, with the least possible bow in its leading edge. The burlapshall be kept wet and free of hardened lumps of concrete. When it fails to produce the required finish, the Contractor shall replace it. When not in use, it shall be lifted clear of the slab.

The surface shall not vary more than 1/8-inch under a 10-foot straightedge placed parallel and perpendicular to the centerline after the slab has cured.

The Contractor shall cut high spots down with a diamond faced, saw-type cutting machine. This machine shall cut through mortar and aggregate without breaking or dislodging the aggregate or causing spalls.

Low spots shall be built up utilizing a grout or concrete with a strength equal to or greater than the required 28-day strength of the Roadway slab concrete. The method of build-up shall be submitted to the Engineer for approval prior to use.

The surface texture on any area cut down or built up shall match closely that of the surrounding deck. The entire bridge roadway slabshall provide a smooth riding surface.

Concrete for sidewalk slabs shall be well compacted, struck off with a strike-board, and floated with a wooden float to achieve a surface that does not vary more than 1/8-inch under a 10-foot straightedge. An edging tool shall be used to finish all sidewalk edges and expansion joints. The final surface shall have a granular texture that does not turn slick when wet.

After placement, concrete surfaces shall be cured as follows:

Concrete Surface	Curing
Slabs (roadway, except those using Class LS; bridge approach slabs, bridge side walks; culvert tops; roofs of cut and cover tunnels)	curing compound covered by white, reflective type sheeting or continuous wet curing for at least 10 days.
Roadway slabs using concrete Class LS	continuous wet cure with heavy quilted blankets or burlap only, for 14 days.
Retaining walls, culvert sidewalls, and culvert floors	continuous moisture for at least ten days.

All other concrete surfaces (except traffic barriers and rail bases) shall be cured withcontinuous moisture for at least three days.

The Contractor may provide continuous moisture by watering a covering of heavy quilted blankets, by watering and covering with a white reflective type sheeting, or by wetting the outside surfaces of wood forms

When curing roadway slabs with wet heavy quilted blankets or burlap, a fog or mist spray of water shall be sprayed on the entire concrete surface before the bleed water has evaporated. As soon as the concrete has achieved initial set, the surface shall be covered with presoaked heavy quilted blankets of burlap. The fog or mist spray shall be applied continuously until the presoaked heavy quilted blankets of burlap are placed. If the fog or mist spray cannot be applied continuously, two coats of curing compound (that complies with Section 9-23.2) shall be applied after the initial fog or mist spray application and before the presoaked heavy quilted blankets of burlap are placed.

When using curing compound, the Contractor shall apply two coats of compoundto the fresh concrete. The compound shall comply with Section 9-23.2 and shall be applied immediately after finishing and afterthe visible bleed of water has evaporated. The second coat shall be applied in a pattern perpendicular to that of the first coat. The two coats shall total at least 1 gallon per 150 square feet and shall obscure the original color of the concrete. If any curing compound spills on construction joints or reinforcing steel, the Contractor shall remove the compound from the construction joint or reinforcing steel before the next concrete pour.

Unless the Contract calls for an asphalt overlay, the Contractor shall use white pigmented curing compound (Type 2), agitating it thoroughly just before and during application. If other Material is to bond with the concrete surface, the Contractor shall remove the curing compound by sandblasting or by acceptable high pressure water washingprior to placing the other Material.

The Contractor shall have on-site, back-up spray equipment, enough workers, and a bridge from which they shall apply the curing compound. The Contractor shall be prepared to demonstrate at least one day before the pour, that the workers and Equipment can apply the compound as specified. No later than the morning after applying the curing compound, the Contractor shall cover the top surfaces with white, reflective sheeting, leaving it in place for at least ten days. The sheeting shall be kept in place by taping or weighting the edges where they overlap.

If the Contract calls for an asphalt overlay, the Contractor shall use the clear curing compound (Type 1D), applying at least 1 gallon per 150 square feet to the concrete slab.

The Contractor shall supply enough water and workers to cure and finish concrete barrier as required in this Section.

Fixed-Form Barrier:

The edge chamfers shall be formed by attaching chamfer strips to the barrier forms. After troweling, edging a barrier, and while the forms remain in place, the Contractor shall:

After removing the forms, the Contractor shall:

The Contractor may do the finishing work described in stepsa. throughd.after removing the forms if the entire barrier, except for the immediate work area,is kept coveredand kept wet. Otherwise, no finishing work may be done until at least 10 days after pouring.

After the 10-day curing period, the Contractor shall remove from the barrier all form-release agent, mud, dust, and other foreign substances in either of two ways: (1) by light sandblasting and washing with water, or (2) by spraying with a high-pressure water jet. The water jet equipment shall use clean fresh water and shall produce (at the nozzle) at least 1500 psi with a discharge of at least 3 gpm. The water jet nozzle shall have a 25-degree tip and shall be held no more than 9 inches from the surface being washed.

After cleaning, the Contractor shall use brushes to rub 1:1 mortar into air holes and small crevices on all surfaces except the brushed top. This mortar shall consist of 1 part Portland cement (of the same brand used in the concrete) and 1 part uncontaminatedfine plaster sand. As soon as the mortar takes its initial set, the Contractor shall rub it off with a piece of sacking or carpet. The barrier shall then be covered with wet quilted blankets for at least 48 hours.

No curing compound shall be used on fixed-form concrete barrier. The completed surface of the concrete shall be even in color and texture.

Slip-Form Barrier:

The edge radius shall be formed by attaching radius strips to the barrier slip forming.

The Contractor shall finish slip-form barrier by steel troweling to close all surface pockmarks and holes. The Contractor shall finish plain surface barrier by lightly brushing the front and back face with vertical strokes and the top surface with crosswise strokes.

After finishing, the Contractor shall cure the slip-form barrier by using either method A (curing compound) or method B (wet blankets) described as follows:

Method A: Under the curing compound method, the Contractor shall:

a. Product Identity,

b. Manufacturer’s recommended application rate,

c. Method of application and necessary equipment,

d. Material Safety Data Sheet (MSDS), and

e. Sample of the material for testing

Allow 14 Working Days for evaluating the proposal and testing the material.

Method B: Under the wet cure method, the Contractor shall:

The Contractor may change construction joints indicated on the Drawings by adding, deleting, or relocating. Any request for such changes shall be submitted to the Engineer for review in accordance with Section 1-05.3(2)D showing the added, deleted, or relocated construction joints. Such changes to construction joints shall be at the sole risk of the Contractor and shall be at no additional cost to the Owner.

All construction joints shall be formed neatly with grade strips or other approved methods. The Engineer will not accept irregular or wavy construction joints. Wire mesh forming material shall not be used. All joints shall be horizontal, vertical, or perpendicular to the main reinforcement. The Contractor shall not use an edger on any construction joint, and shall remove any lip or edging before making the adjacent pour.

If the Drawings require a roughened surface on the joint, the Contractor shall strike it off to leave grooves at right angles to the length of the member. The grooves shall be 1/2 inch to 1 inch wide, 1/4 inch to 1/2 inch deep, and spaced equally at twice the width of the groove. If the first strike-off does not produce the required roughness, the Contractor shall repeat the process before the concrete reaches initial set. The final surface shall be clean and without laitance or loose material.

The Contractor shall include shear keys at all construction jointswhere a roughened surface is not required on the Drawings. These shear keys shall provide a positive, mechanical bond. Shear keys shall be formed depressions and the forms shall not be removed until the concrete has been in place at least 12 hours. Forms shall be slightly beveled to ensure ready removal. Raised shear keys are not allowed.

Shear keys for the tops of beams, at tops and bottoms of boxed girder webs, in diaphragms, and in crossbeams shall:

Before placing new concrete against cured concrete, the Contractor shall thoroughly clean and roughen the cured face and wet it with water. Before placing the reinforcing mat for footings on seals, the Contractor shall:

(1) remove all scum, laitance, and loose gravel and sediment;

(2) clean the construction joint at the top of the seals; and

(3) chip off any high spots on the seals that would prevent the footing steel from being placed in the position required by the Drawings.

This Section outlines the requirements of specific expansion joints shown on the Drawings, unless the Contract specifies otherwise.

Joints made of a vulcanized, elastomeric compound (with neoprene as the only polymer) shall be installed with an approved lubricant adhesive as recommended by the manufacturer. The length of a seal shall match that required on the Drawings without splicing or stretching.

Open joints shall be formed with a template made of wood, metal, or other suitable material. Insertion and removal of the template shall be done without chipping or breaking the edges or otherwise damaging the concrete. Joint surfaces shall be parallel with a tolerance varying not more than 1/16 the joint spacingin any 10 foot length.

Any part of an expansion joint running parallel to the direction of expansion shall provide a clearance of at least 1/2 inch between the two surfaces. The clearance shall be produced by inserting and removing a spacer strip. The Contractor shall ensure that the surfaces meet the parallel requirements to prevent any wedging from expansion and contraction.

All poured rubber joint sealer (and any required primer) shall conform with Section 9-04.2(2).

The expansion joints shall be as shown and noted on the Drawings.

The Contractor shall submit Shop Drawings of the expansion joints proposed for use to the Engineer. Submittal of Shop Drawings shall be in accordance with provisions of Section 1-05.3. The Shop Drawings shall show details of the system(s), including materials and dimensions, method of installation, method of sealing the system to prevent leakage of water through the joint, andthe manufacturer’s written installation procedures.

After the joint system(s) is installed, the joint area shall be sandbagged, flooded with 4 inches of water for 24 hours and inspected from below the joint for leakage. If leakage is observed, the joint system shall be repaired as recommended by the manufacturer including review of the manufacturer's recommendation by the Engineer.

To aid in assuring proper use and installation of the expansion joint system under job conditions, the Contractor shall have available during installation of the jointsystem and at no additionalcost to the Owner, the services of a qualified, full-time field representative of the manufacturer of the expansion joint system to be installed in the Project. Recommendations made by the manufacturer’s representative and reviewed by the Engineer, shall be adhered to by the Contractor at no additional cost to the Owner.

The expansion joints shall seal the roadway deck surface, curbs, and sidewalks to prevent water from passing through the joint to portions of the Structure below. Installation of the expansion joints and painting of the exposed metal parts shall be in accordance with the manufacturer’s recommendations. The sealant recommended by the manufacturer supplying the expansion joint shall be submitted for review by the Engineer before installation. The transition of the expansion joint from the roadway, up the curb face and horizontally to the back of the curb shall be in a continuous factory fabricated curb/gutter unit.

The seats for the expansion joints shall be absolutely parallel to longitudinal and transverse roadway grade and shall match the transverse crown of the final pavement surface. All spalls, low areas or high areas in the expansion joint seat shall be recontoured so that the variation is no more than 1/16 inch from a 10-foot straightedge on a constant cross slope and from a 3-foot straightedge on a parabolic crown. Each successive check with the straightedge device shall lap the previous check by at least 1/2 of the length of the straightedge. All concrete outside corners of the expansion joint slot shall have a radius of rounding of 1/4 inch.

When the expansion joint seat consists of steel plates or steel angles, all high areas shall be ground and all low areas having a depth of less than 1/4 inch from the true seat contour shall be filled with an approved epoxy. Areas with a depth greater than 1/4 inch shall be filled with an approved epoxy sand grout. The tolerance from a 10-foot or 3-foot straightedge shall be the same as stated above for concrete seats.

The expansion joint material shall have full firm bearing for the entire length and width of the joint. The expansion joint material shall be placed so that its top surface is recessed 1/8 inch ±1/16 inch below the driving surface of the pavement on both sides of the expansion joint.

Shims, washers or other devices shall not be used below the expansion joint material to bring the joint either to proper elevation or to proper tolerance.

All aluminum surfaces that will be in contact with concrete shall be coated with zinc chromate or a bituminous paint as recommended by the manufacturer.

The groove or recess for compression seals shall have parallel sides and be constructed to the proper depth. The width of the recess shall not vary more than 1/16 inch in a distance of 10 feet. The bottom shall be a smooth surface parallel to the surface of the roadway, curb, or sidewalk.

The Contractor shall furnish and install compression seals of the size and type specified at the locations indicated on the Drawings and according to the following provisions:

The seals shall conform to the requirements of ASTM D 2000 and shall be formed by an extrusion process resulting in a dense neoprene with uniform dimensions and smooth exterior surface.

The cross section of the seal shall be shaped to allow adequate compression of the seal under design conditions. The length of seals shall be as indicated on the Drawings. Stretching of the seals will not be permitted. Details of the seal, including corner joints and type of material to bond joints shall be submitted to the Engineer review before submitting samples for lot acceptance. A lot shall be considered all material of one size produced during one production run for use on the Project. A sample shall consist of a 3-foot length of actual seal. The Supplier of the joint seals shall furnish the Engineer a certified copy of the test results indicating that the Material complies with the Specification requirements including catalog cuts, Shop Drawings, and Manufacturer’s Certificate of Compliance.

The seal shall be installed with an approved lubricant adhesive in accordance with the manufacturer’s recommendations. The lubricant adhesive shall be delivered in containers plainly marked with the manufacturer’s name or trademark, lot number and date of manufacture. A one pint sample of lubricant adhesive shall be furnished to the Engineer for approval prior to installation.

All surfaces to receive elastomeric compression seal shall be free from dirt, water, oil, rust, frost, spalls, cracks, and any loose debris.

It is imperative that a clean opening, with 1/4 inch rounded top edges, shall be produced for the specified opening and for the full depth of joint required. All joint grooves shall be inspected for spalling after the joints are constructed and all foreign materials removed from the joint grooves. Spalling thatincreases the specified size of the joint groove beyond the following limits shall be repaired by patching with epoxy mortar:

Where indicated on the Drawings, the Contractor shall install the proper seals inaccordance with the Contract. The air temperature shall be below 85°Fat the time of installation.

Compression seals shall be recessed 3/8 inch from the finished grade with a tolerance of 1/16 inch in 10 feet.

At end joints or miter joints as shown on the Drawings, a 1/4-inch thick neoprene sponge shall be bonded to the seal ends with an approved cyanoacrylate adhesive. The neoprene sponge shall be cut to the size and shape of the nominal dimensionsof the uncompressed seal. The seal plus the sponge shall be slightly longer than the gap to be filled so that the sponge is in a state of compression against the ends of the seal. The cyanoacrylate adhesive shall onlybe applied to outer webs and top web of the seal to allow entrapped air to escape.

At seal upturn or downturn locations, the installation procedure shall be as follows (see detail on the Drawings):

The seal surface to be bonded shall be cleaned with toluene or othersolvent recommended by the seal manufacturerprior to applying adhesive. Controls shall be in place for controlling and containing the toluene or other solvent material as required in Section 1-07. A continuous coat of adhesive shall be applied to both joint interfaces immediately prior to seal installation. Adhesive shall not be applied below 40°F. The compression seal shall be placed such that the top surface, or surface facing the front of the curb, shall be recessed 1/8-inch ±1/16 inch into the adjacent concrete surface.

All concrete shall show a smooth, dense, non-porousface after the forms are removed. The removing and replacing ofany concrete showing porous, or not smooth, or non-dense concrete shall be at no additional cost to the Owner. The Contractor shall clean and refinish any stained or discolored surfaces that may have resulted from his/her work or from construction delays.

Subsections 6-02.3(14)B, 6-02.3(14)C, and 6-02.3(14)D describe three classes of surface finishing. The Contractor shall comply with these subsections unless the Contractrequires otherwise.

The Contractor shall apply a Class 1 surface finish to all rail bases, curbs, traffic barrier, pedestrian barrier, and ornamental concrete members.

Class 1 surface finish requires the same treatment as Class 2 surface finish (see the following Section) but also includes the finishing steps outlined in Section 6-02.3(11)B.

The Contractor shall apply a Class 2 surface finish to:

The Contractor shall comply with stepsa. throughh. that follow. The Contractor may omit stepsc. throughh. below when steel forms have been used and when the surface of filled holes matches the texture and color of the area around them. To create a Class 2 surface finish, the Contractor shall:

If the mortar becomes too hard to rub off as described in step 6, the Contractor shall remove it with a carborundum stone and water. Random grinding is not permitted.

The Contractor shall apply a Class 3 surface finish to:

To produce a Class 3 surface finish, the Contractor shall:

Nothing further is required if the Engineer decides these 2 steps have produced an acceptablesurface finish. Otherwise, the Contractor shall follow other Class 2 surface finish steps until the Engineer approves the work as a final Class 3 surface finish.

Standard date numerals shall be placed where shown on the Drawings. The date shall be for the year in which the Structure is completed. When a traffic barrier is placed on an existing Structure, the date shall be for the year in which the original structure was completed.

The Contractor shall submit all Shop Drawings for falsework and formwork for review directly to the Engineer. All falsework and formwork shall be constructed in accordance with reviewed falsework and formwork Shop Drawings.

Except for the placement of falsework foundation pads and piles, the construction of any unit of falsework shall not start until the Engineer has reviewed the falsework Shop Drawing submittal for that unit. Driven piles for falsework, temporary concrete footings, or timber mudsills may be placed as described in Section 6-02.3(17)E prior to the Engineer's review at the Contractor’s own risk, except for the following conditions:

If the Project involves a railroad or the U.S. Bureau of Reclamation, thefollowing additional sets for the portion of the Project that involves the railroad or U.S. Bureau of Reclamationshall be sent to the Engineer:

The Engineer will review the falsework and formwork Shop Drawings and calculations, and will requestthe required reviewsfrom the appropriate railroad company or the U.S. Bureau of Reclamation.After the Engineer has received any comments from the railroad company or the U.S. Bureau of Reclamation, two copies of the reviewed falsework and formwork Shop Drawings, with comment when applicable, will be returned to the Contractor.

Shop Drawingreview is not required for footing or retaining walls unless they are more than 4 feet high excluding pedestal height.

The design of falsework and formwork shall be based on:

The falsework and formwork Shop Drawings shall be scale drawings showing the details of proposed construction, including, but not limited to.

a. sizes and properties of all members and components;

b. spacing of bents, posts, studs, wales, stringers, wedges and bracing;

c. rates of concrete placement, placement sequence, direction of placement, and location of

construction joints; and

d. identify falsework devices and safe working load as well as identifying any bolts or threaded rods

used with the devices including their diameter, length, type, grade, and required torque.

Show in the falsework Shop Drawing submittals the proximity of falsework to utilities or any nearby Structures including underground Structures. Formwork accessories shall be identified according to Section 6-02.3(17)I, “Formwork Accessories”. All assumptions, dimensions, material properties, and other data used in making the structural analysis shall be noted on the Shop Drawing submittal.

In accordance with the requirements of Section 1-05.3(2)F, all falsework and formwork Shop Drawings and design calculations shall be prepared by (or under the direct supervision of) a Professional Engineer, licensed under Title 18 RCW, State of Washington, in the branch of Civil or Structural Engineering. The Contractor shall furnish two copies of the associated design calculations to the Engineer for examination as a condition forreview. The design calculations shall show the stresses and deflections in load supporting members. Construction details which may be shown in the form of sketches on the calculation sheets shall be shown in the falsework or formwork Shop Drawings as well. Falsework or formwork Shop Drawings will not be reviewed in any case where it is necessary to refer to the calculation sheets for information needed for complete understanding of the falsework and formwork Shop Drawings or how to construct the falsework and formwork.

Pre-approval of falsework and formwork Shop Drawings will not be allowed.

Contractor revisions to reviewed Shop Drawings returned by the Engineer shall require a resubmittal of the reviewed Shop Drawings clearly indicating all revision with supporting calculation. The Contractor shall take into consideration any additional time required by the Engineer to perform additional review of previously reviewed Shop Drawings. The Contractor agrees to make no claim whatsoever both for adjustment to Contract Time and/or for additional compensation.

Formwork and falsework are both structural systems. Formwork contains the lateral pressure exerted by concrete placed in the forms. Falsework supports the vertical and/or the horizontal loads of the formwork, reinforcing steel, concrete, and live loads during construction.

The Contractor shall set falsework, to produce in the finished structure, the lines and grades indicated on the Drawings. The setting of falsework shall allow for shrinkage, settlement, falsework girder camber, and any structural camber the Contractrequires.

Concrete forms shall be mortar tight andtrue to the dimensions, lines, and grades of the concretestructure. Curved surfaces shown on the Drawings shall be constructed as curved surfaces and not chorded, except as allowed in Section 6-02.3(17)K. Concrete formwork shall prevent overstress and excess deflection as defined in Section 6-02.3(17)C. The rate of depositing concrete in the forms shall not exceed the placement rate in the submitted and reviewed formwork Shop Drawing. The interior form shape and dimensions shall also ensure that the finished concrete conforms with the Drawings.

If the new Structure is near or part of an existing one, the Contractor shall not suspend or support falsework onthe existing structure unless theContract states otherwise. For prestress girder and T-beam bridge widenings or stage construction, the roadway deck and the diaphragm forms may be supported from the existing structure or previous stage, if approved by the Engineer. For steel plate girder bridge widenings or stage construction, only the roadway deck forms may be supported from the existing structure or previous stage, if approved by the Engineer. See Section 6-02.3(17)F for additional conditions.

Forms designed to stay in place on bridge roadway slabs shall not bemade of steel or precast concrete panels.

For post-tensioned structures, both falsework and forms shall be designed to carry the additional loads caused by the post-tensioning operations. The Contractor shall construct supporting falsework in a way that leaves the Superstructure free to contract and lift off the falsework during post-tensioning. Forms that remain inside box girders to support the placement of the roadway slab concrete shall, by design, not resist girder contraction. See Section 6-02.3(26) for additional conditions.

Concrete barriers shall be used to protect falsework adjacent to Traffic from damage by vehicles.

The design load for falsework shall consist of the sum of dead and live vertical loads, and a design horizontal load. The minimum total design load for any falsework shall not be less than 100 pounds per square foot for combined live and dead load regardless of structure thickness.

The entire Superstructure cross-section, except for traffic barrier, shall be considered to be placed at one time for purposes of determining support requirements and designing falsework girders for their stresses and deflections, except as follows:

For concrete box girder bridges, the girder stems, diaphrams, crossbeams, and connected bottom slabs, if the stem wall is placed more than 5 days prior to the top slab, may be considered to be self supporting between falsework bents at the time the top slab is placed, provided that the distance between falsework bents does not exceed 4 times the depth of the portion of the girder placed in the preceding concrete placements.

Falsework bents shall be designed for the entire live load and dead load, including all load transfer that takes place during post-tensioning, and braced for the design horizontal load.

Dead loads shall include the weight of all successive placements of concrete, reinforcing steel, forms and falsework, and all load transfer that takes place during post-tensioning. The weight of concrete with reinforcing steel shall be assumed to be not less than 160 pounds per cubic foot.

Live loads shall consist of the actual weight of any equipment to be supported by falsework applied as concentrated loads at the points of contact, and a minimum uniform load of not less than 25 pounds per square foot applied over the entire falsework Shop Drawing submittal area supported, plus a minimum load of not less than 75 pounds per linear foot applied at the outside edge of deck overhangs.

The design horizontal load to be resisted by the falsework bracing system in any direction shall be:

The sum of all identifiable horizontal loads exertedby equipment, construction sequence, sidesway caused by geometry or eccentric loading conditions, or other causes, and an allowance for wind plus an additional allowance of 1 percent of the total dead load to provide for unexpected forces. In no case shall the design horizontal load be less than three percent of the total dead load.

The minimum horizontal load to be allowed for wind on each heavy-duty steel shoring tower having a vertical load carrying capacity exceeding 30 kips per leg shall be the sum of the products of the wind impact area, shape factor, and the applicable wind pressure value for each height zone. The wind impact area is the total projected area of all the elements in the tower face normal to the applied wind. The shape factor for heavy-duty steel shoring towers shall be taken as 2.2. Wind pressure values shall be determined from the following table:

WIND PRESSURE ON HEAVY-DUTY STEEL SHORING TOWERS
	Wind Pressure Value
Height Zone (Feet above Ground)	Adjacent to Traffic	At Other Locations
0 to 30	20 psf	15 psf
30 to 50	25 psf	20 psf
50 to 100	30 psf	25 psf
Over 100	35 psf	30 psf

The minimum horizontal load to be allowed for wind on all other types of falsework, including falsework girders and forms supported on heavy-duty steel shoring towers, shall be the sum of the products of the wind impact area and the applicable wind pressure value for each height zone. The wind impact area is the gross projected area of the falsework support system, falsework girders, forms and any unrestrained portion of the permanent structure, excluding the areas between falsework posts or towers where diagonal bracing is not used. Wind pressure values shall be determined from the following table:

WIND PRESSURE ON ALL OTHER TYPES OF FALSEWORK
	Wind Pressure Value
Height Zone(Feet above Ground)	For Members Over and Bents Adjacent to Traffic Openings	At Other Locations
0 to 30	2.0 Q psf	1.5 Q psf
30 to 50	2.5 Q psf	2.0 Q psf
50 to 100	3.0 Q psf	2.5 Q psf
Over 100	3.5 Q psf	3.0 Q psf

The value of Q in the above tabulation shall be determined as follows:

Q = 1 + 0.2W; but Q shall not be more than 10.

Where:

W is the width of the falsework system, in feet, measured in the direction of the

wind force being considered.

The falsework system shall also be designed so that it is sufficiently stable to resist overturning prior to the placement of the concrete. The minimum factor of safety against falsework overturning in all directions from the assumed horizontal load for all stages of construction shall be 1.25. If the required resisting moment is less than 1.25 times the overturning moment, the difference shall be resisted by bracing, cable guys, or other means of external support.

Design of falsework shall include the vertical component, whether positive or negative, of bracing loads imposed by the design horizontal load. Design of falsework shall include the effects of any horizontal displacement due to stretch of the bracing, particularly when using cable or rod bracing systems.

If the concrete is to be post-tensioned, the falsework shall be designed to support any increased or redistributed loads caused by the prestressing forces.

The maximum allowable stresses listed in this Section are based on the use of identifiable, undamaged, high-quality materials. Stresses shall be appropriately reduced if lesser quality materials are to be used.

These maximum allowable stresses include all adjustment factors, such as the short term load duration factor. The maximum allowable stresses and deflections used in the design of the falsework and formwork shall be as follows:

Deflection:

Deflection resulting from dead load and concrete pressure for exposed visible surfaces, such as the sides and bottoms of girders, regardless of the fact that the deflection due to the weight of all successive placements of concrete, reinforcing steel and forms may be compensated for by camber strips; sides of abutments, wingwalls, piers, retaining walls, and columns = 1/500 of the span.

Deflection resulting from dead load and concrete pressure for unexposed non-visible surfaces, including the bottom of the deck slab between girders, regardless of the fact that the deflection due to the weight of all successive placements of concrete, reinforcing steel and forms may be compensated for by camber strips = 1/360 of the span.

In the foregoing, the span length shall be the center line to center line distance between supports for simple and continuous spans, and from the center line of support to the end of the member for cantilever spans. For plywood supported on members wider than 1 1/2 inches, the span length shall be taken as the clear span plus 1 1/2 inches. Also, dead load shall include the weight of all successive placements of concrete, reinforcing steel, forms and falsework self weight. Only the self weight of falsework girders may be excluded from the calculation of the above deflections provided that the falsework girder deflection is compensated for by the installation of camber strips.

Where successive placements of concrete are to act compositely in the completed structure, deflection control becomes extremely critical. For members constructed in several successive placements, such as concrete box girder and concrete T-beam girder structures, falsework components shall be sized, positioned, and/or supported to minimize progressive increases in deflection of the structure which would preload the concrete or reinforcing steel before it becomes fully composite.

Timber:

Each species and grade of timber orlumber used in constructing falsework and formwork shall be identified in the ShopDrawings. The allowable stresses and loads shall not exceed the lesser of stresses and loads given in the following table or factored stresses for designated species and grade in Table 7.3 of the Timber Construction Manual, Third Edition by the American Institute of Timber Construction.

Compression perpendicular to the grain reduced to 300 psi for use when moisture content is 19 percent or more (areas exposed to rain, concrete curing water, green lumber).	450 psi
Compression parallel to the grain but not to exceed 1,500 psi.	480,000 psi (L/d)2
Flexural stress for members with a nominal depth greater than 8 inches.	1,800 psi
Flexural stress psi for members with a nominal depth of 8 inches or less.	1,500 psi
The maximum horizontal shear.	140 psi
AXIAL tension.	1,200 psi
The maximum modulus of elasticity (E) for timber.	1,600,000 psi

Where:

L is the unsupported length; and

d is the least dimension of a square or rectangular column, or the width of a square of equivalent cross-sectional area for round columns.

The allowable stress for compression perpendicular to the grain, and for horizontal shear shall not be increased by any factors such as short duration loading. Additional requirements are found in other parts of Section 6-02.3(17). Criteria for the design of lumber and timber connections are found in Section 6-02.3(17)J.

Plywood for formwork shall be designed in accordance with the methods and stresses allowed in the APA Design/Construction Guide for Concrete Forming as published by the American Plywood Association, Tacoma, Washington. As concrete forming is a special application for plywood, wet stresses shall be used and then adjusted for forming conditions such as duration of load, and experience factors. Concrete pour pressures shall be per Section 6-02.3(17)K.

Steel:

For identified grades of steel, design stresses shall not exceed those specified in the Manual of Steel Construction - Allowable Stress Design, Ninth Edition by the American Institute of Steel Construction, except as follows:

Compression, flexural but not to exceed 0.6Fy	12,000,000 psi Ld/bt
The modulus of elasticity (E) shall be	29,000,000 psi

When the grade of steel cannot be positively identified as with salvaged steel and if rivets are present, design stresses shall not exceed the following:

Yield point fy 30,000 psi

Tension, axial, and flexural 16,000 psi

Compression, axial 14,150 - 0.37(KL/r)² psi

except L/r shall not exceed 120

Shear on gross section of the web of rolled shapes 9,500 psi

Web crippling for rolled shapes 22,500 psi

Compression, flexural but not to exceed 16,000 - 5.2(L/b)² psi

16,000 psi and L/b not greater than 39

The modulus of elasticity (E) shall be 29,000,000 psi

Where:

L is the unsupported length;

d is the least dimension of rectangular columns, or the width of a square of equivalent cross-sectional area for round columns, or the depth of beams;

b is the flange width;

t is the thickness of the compression flange;

r is the radius of gyration of the compression flange about the weak axis of the member; and

Fy is the specified minimum yield stress, psi, for the grade of steel used.

All dimensions are expressed in inches.

In addition to the minimum requirements specified in Sections 6-02.3(17)B and 6-02.3(17)C, falsework over or adjacent to roadways or railroads which are open to Traffic or the public shall be designed and constructed so that the falsework is stable if subjected to impact by vehicles. The use of damaged materials, unidentifiable material, salvaged steel or steel with burned holes or questionable weldments shall not be used for falsework described in this section.

For the purposes of this Specification Section, the following public or private facilities shall also be considered as “Roadways”:

pedestrian pathways and other Structures such as bridges, walls, and buildings.

The dimensions of the clear openings to be provided through the falsework for roadways, railroads, or pedestrian pathways shall be as specified in Contract.

Falsework posts or shoring tower systems which support members that cross over a roadway or railroad shall be considered as adjacent to roadways or railroads. Other falsework posts or shoring towers shall be considered as adjacent to roadways or railroads only if the following conditions apply:

The Contractor shall provide any additional features for the work needed to ensure that the falsework is stable for impact by vehicles; providing adequate safeguards, safety devices, protective equipment, and any other needed actions to protect property and the life, health, and safety of the public; and shall comply with the provisions in Section 1-07.23, Section 1-10, and Section 6-02.3(17)N. The falsework design at special locations, shall incorporate the minimum requirements detailed in this Section, even if protected by concrete median barrier.

The vertical load used for the design of falsework posts and towers which support the portion of the falsework over openings, shall be the greater of the following:

Each falsework post or each shoring tower leg adjacent to Roadways or railroads shall consist of either steel with a minimum section modulus about each axis of 9.5 inches cubed (or 9.5 inch3) or sound timbers with a minimum section modulus about each axis of 250 inches cubed (or 250 inch3).

Each falsework post or shoring tower leg adjacent to Roadways or railroads shall be mechanically connected to its supporting footing at its base, or otherwise laterally restrained, to withstand a loadof not less than 2,000 pounds applied at the base of the post or tower leg in any direction except toward the roadway or railroad track. Posts or tower legs shall be connected to the falsework cap and stringer by mechanical connections capable of resisting a load in any horizontal direction of not less than 1,000 pounds.

For falsework spans over Roadways and railroads, all falsework stringers shall be mechanically connected to the falsework cap or framing. The mechanical connections shall be capable of resisting a load in any direction, including uplift on the stringer, of not less than 500 pounds. All associated connections shall be installed before Trafficis allowed to pass beneath the span.

When timber members are used to brace falsework bents which are located adjacent to Roadways or railroads, all connections shall be bolted through the members using 5/8-inch diameter or larger bolts.

Concrete traffic barrier shall be used to protect all falsework adjacent to traveled Roadways. The falsework shall be located so that falsework footings, mudsills, or piles are at least 2 feet clear of the traffic barrier and all other falsework members shall also be at least 2 feet clear of the traffic barrier. Traffic barrier used to protect falsework shall not be fastened, guyed, or blocked to any falsework but shall be fastened to the pavement according to details shown on the Drawings. The installation of concrete traffic barrier shall be completed before falsework erection is begun. The traffic barrier at the falsework shall not be removed until approved by the Engineer. Falsework openings which are provided for the Contractor’s own use (not for public use) shall also use concrete traffic barrier to protect the falsework, except the minimum clear distance between the barrier and falsework footings, mudsills, piles, or other falsework members shall be at least 3 inches.

Falsework bents within 20 feet of the center line of a railroad track shall be braced to resist the required horizontal load or 2,000 pounds whichever is greater.

In addition to the requirements of Section 1-07.23, pedestrian openings through falsework shall be paved or surfaced with full width continuous wood walks which shall be wheel chair accessible and shall be kept clear. Pedestrians shall be protected from objects and water falling from construction above. Overhead protection for pedestrians shall extend at least 4 feet beyond the edge of the bridge deck. Shop Drawings and details of the overhead protection and pathway shall be submitted with the falsework Shop Drawing submittals to the Engineer for review. Pedestrian openings through falsework shall be illuminated by temporary lighting, constructed and maintained by the Contractor. The temporary lighting shall be constructed in accordance with local electrical code requirements. The temporary lighting shall be steady burning and shall be a minimum 60 watt, 120 volt lamps with molded waterproof lamp holders spaced at 25 feet centers maximum. All costs relating to pedestrian pathway paving, wood walks, overhead protection, maintenance, operating costs, and temporary pedestrian lighting shall be incidental to applicable Bid items of Work and shall be at no additional cost to the Owner.

The Contractor shall support all falsework on either driven piles, temporary concrete footings, or timber mudsills. Temporary concrete footings shall be designed as reinforced concrete which may be either cast in place or precast. All components for a falsework support system shall be sized for the maximum design loads and allowable stresses described in the preceding Sections.

The falsework Shop Drawing submittals shall include a Superstructure placing diagram showing the concrete placing sequence, direction of placements, and construction joint locations. When a sequence for placing concrete is shown in the Contract, no deviation will be permitted.

If the Contract calls for piles or foundation shafts to support permanent structures, the Contractor may not use mudsills or temporary concrete footings for falsework support unless the underlying soil passes the settlement test described in this Section.

Piles:

When using piles to support the falsework, the Contractor’s falsework Shop Drawing submittal shall specify the minimum required bearing and depth of penetration for the piles. The falsework Shop Drawing submittals shall also show the maximum horizontal distance that the top of a falsework pile may be pulled in order to position it under its cap. The falsework Shop Drawing submittal shall show the maximum allowable deviation of the top of the pile, in its final position, from a vertical line through the point of fixity of the pile. The calculations shall account for pile stresses due to combined axial and flexural stress and secondary stresses.

Untreated timber piles shall be banded atthe top before driving. The following shall be identified in the falsework Shop Drawing submittal: lengths, minimum tip diameter, and expected diameter at ground line. The Contractor shall comply with the requirements of Section 9-10.1(1). The maximum allowable load for timber piles shall be 45 tons.

Steel piles shall be identified in the falsework Shop Drawing submittal. If steel pipe pile is used, the pipe diameter and wall thickness shall be identified in the falsework Shop Drawing submittal. Steel piles shall meet the requirements of Section 9-10.5. The applicable Specifications in Section 6-05 shall be used to determine the bearing capacity of the falsework piles. The pile bearing capacity may instead be determined by test loading the pile to twice the falsework designload if approved in writing by the Engineer. The Contractor shall provide the Engineer an opportunity to witness these tests and to submit a plan of the test and cross-sections showing the locations and elevations of the proposed tests to the Engineer for approval.

Temporary Concrete Footings and Timber Mudsills:

Timber mudsills or temporary concrete footings may be used in place of driven piles if Contractor provided tests show that the soil can support twice the falsework design load, and that the mudsill or temporary concrete footing shall not settle more than 1/4-inch when loaded with the design load. The tests shall be done at the falsework site, at the same elevation of the mudsill, and conducted under conditions representative of the actual site conditions. The acceptable tests for various soil types are:

Timber mudsills or temporary concrete footings for falsework shall be designed to carry the loads imposed upon them without exceeding the estimated soil bearing capacity and specified maximum settlement. Where mudsills or temporary footings are used in the vicinity of permanent spread footings, the allowable mudsill bearing pressure shall be less than that of the permanent footings. This is because elevation difference; smaller bearing area; and the lack of surrounding overburden provides a lower bearing capacity than the permanent spread footings. Mudsills shall be designed for bearing capacities at the location that they are to be used. Timber mudsills or temporary concrete footings shall be designed as unyielding foundations under full design loads. The soil pressure bearing values assumed in the design of the falsework (normally not more than 3,000 pounds per square foot) shall be shown in the falsework Shop Drawing submittals. The minimum edge distances from the edge of the post or shoring tower leg to the edge or end of the mudsill member shall be shown in the falsework Shop Drawing submittals. Timber mudsills and temporary concrete footings shall be designed such that member deflections do not exceed 1/4-inch and that member allowable stresses are not exceeded.

Full cross-sectional views of all falsework on timber mudsills or temporary concrete footings to be placed in side slopes or above excavations shall be shown in the falsework Shop Drawing submittals. Footings or mudsills which are stepped or placed above an excavation shall have all related geometry and slope stability items identified in the falsework Shop Drawing submittal. Details and calculations for any shoring system to support the embankment or excavation shall be included.

Mudsills or temporary concrete footings placed in benches in slopes shall be set back from the face of the slope one-half the mudsill or temporary concrete footing width, but not less than 1 foot 0 inches. The bench including the setback shall be level in its narrow dimension. Slopes between benches measured from the top of slope at one bench to the toe of slope at the next bench below shall be no steeper than 1-1/2 horizontal to 1 vertical.

Falsework shall be founded on a solid footing, safe against undermining, protected from softening, and capable of supporting the loads imposed. The preparation of the soil to receive the temporary footing is important to ensure that the falsework does not experience localized settlement that could result in falsework failure. In preparing the soil for a timber mudsill or temporary concrete footing, the Contractor shall:

Anticipated total settlements and incremental settlements of falsework and forms due to successive concrete placements shall be shown in the falsework Shop Drawing submittals. These shall include falsework footing settlement and joint take-up. Total anticipated settlements shall not exceed one inch including joint take-up. When using mudsills, the Contractor shall prepare for the possibility of reshoring with the use of such devices as screw jacks or hydraulic jacks and adjustment of wedge packs. The placing of concrete shall be discontinued if unanticipated settlement occurs, including settlements that deviate more than 3/8-inch from those indicated on thereviewed falsework Shop Drawing submittal. Concrete placement shall not resume until the Contractor provides corrective measures that are acceptable to the Engineer. Placing of concrete shall be discontinued if acceptable corrective measures are not provided the to Engineer prior to initial set of the concrete in the affected area. All unacceptable concrete shall be removed.

Where the maximum leg load exceeds 30 kips, foundations for individual steel towers shall be designed and constructed to provide uniform settlement at each tower leg for all loading conditions.

Bents, Shoring Towers, Piles, Posts, and Caps:

Shop Drawings for falsework bents or shoring tower systems, including manufactured tower systems shall have plan, cross-section, and elevation view scale Shop Drawings showing all geometry. Show in the falsework Shop Drawing submittals the proximity of falsework to utilities or any nearby structures including underground structures. The ground elevation, cross-slopes, relation of stringers to one another, and dimensions to posts or piles shall be shown in the falsework Shop Drawing submittals. Column, pile, or tower heights shall be indicated. Member sizes, wall thickness and diameter of steel pipe columns or piles shall be shown in the falsework Shop Drawing submittals. Location of wedges, minimum bearing area and type of wedge material shall be identified in the falsework Shop Drawing submittals. Bracing size, location, material and all connections shall be described in the falsework Shop Drawing submittals.

The relationship of the falsework bents or shoring tower systems to the permanent Structure’s pier and footing shall be shown. Load paths shall be as direct as possible. Loads shall be applied through the shear centers of all members to avoid torsion and buckling conditions. Where appliedloads cause twisting, biaxial bending, or axial loading with bending, the affected members shall be designed for combined stresses and stability.

Posts or columns shall be constructed plumb with tops and bottoms carefully cut to provide full end bearing. Caps shall be installed at all bents supported by posts or piles unless Engineer reviewed falsework Shop Drawing submittals specifically permit otherwise. Caps shall be fastened to the piles or posts. The falsework shall be capable of supporting nonuniform or localized loading without adverse effect. For example, the loading of cantilevered ends of stringers or caps shall not cause a condition of instability in the adjacent unloaded members.

Timber posts and piles shall be fastened to the caps and mudsills using through-bolted connections, drift pins, or other connections indicated on the Shop Drawings and reviewed by the Engineer. The minimum diameter of round timber posts shall be shown in the falsework Shop Drawing submittals. Timber caps and timber mudsills shall be checked for crushing from columns or piles under maximum load.

Steel posts and piles shall be welded or bolted to the caps and to the foundation. Steel members shall be checked for buckling, web yielding, and web crippling.

Wedges shall be used to permit formwork to be taken up and released uniformly. Wedges shall be oak. Cedar or other soft wood wedges or shims shall not be used anywhere in a falsework or forming system. Wedges shall be used at the top or the bottom of shores, but not at both top and bottom. After the final adjustment of the shore elevation is complete, the wedges shall be fastened securely to the sill or cap beam. The method of securely fastening wedges shall be included in the submittal. Only one set of wedges, with one optional block, shall be used at one location.Screw jacks, or other devices shown on the Shop Drawings for the Engineer's review, shall be used under arches to allow incremental release of the falsework.

Sand jacks may be used to support falsework and are used for falsework lowering only. Sand jacks shall be constructed of steel with snug fitting steel or concrete pistons. Sand jacks shall be filled with dry sand and the jack protected from moisture throughout its use. They shall be designed and installed in such a way to prevent the unintentional migration or loss of sand. All sand jacks shall be tested per Section 6-02.3(17)H.

When falsework is over or adjacent to Roadways or railroads, all details of the falsework system which contribute to the horizontal stability and resistance to impact shall be installed at the time each element of the falsework is erected and shall remain in place until the falsework is removed. For other requirements see Section 6-02.3(17)D.

Transverse construction joints in the Superstructure shall be supported by falsework at the joint location. The falsework shall be constructed in such a manner that subsequent pours shall not produce additional stresses in the concrete already in place.

Manufactured Shoring Tower Systems and Devices:

Manufactured proprietary shoring tower systems shall be identified in the falsework Shop Drawing submittal by make and model and safe working load capacity per leg. The safe working load for shoring tower systems shall be based upon a minimum 2-1/2 to 1 factor of safety.

The safe working load capacity, anticipated deflection (or settlement), make and model shall be identified in the falsework submittal for manufactured devices such as: single shores, overhang brackets, support bracket and jack assemblies, friction collars and clamps, hangers, saddles, and sand jacks. The safe working load for shop manufactured devices shall be based on a minimum ultimate strength safety factor of 2 to 1. The safe working load for field fabricated devices and all single shores shall be based on a minimum ultimate strength safety factor of 3 to 1.

The safe working load of all devices shall not be exceeded. The design loads shall be as defined by Section 6-02.3(17)B. The maximum allowable free end deflection of deck overhang brackets under working loads applied shall not exceed 3/16 inch regardless of the fact that the deflection may be compensated for by pre-cambering or of setting the elevations high. The Contractor shall comply with all manufacturer’s specifications; including those relating to bolt torque, placing washers under nuts and bolt heads, cleaning and oiling of parts, and the reuse of material. Devices which are deteriorated, bent, warped, or have poorly fitted connections or welds, shall not be installed.

Shoring tower or device capacity as shown in catalogs or brochures published by the manufacturer shall be considered as the maximum load which the shoring is able to safely support under ideal conditions. These maximum values shall be reduced for adverse loading conditions; such as horizontal loads, eccentricity due to unbalanced spans or placing sequence, and uneven foundation settlement.

Depending on load-carrying capacity, steel shoring systems are classified as pipe-frame systems, intermediate strength systems, and heavy-duty systems. The two types of pipe-frame shoring base frames in general use are the ladder type and the cross-braced type. In the ladder type, frame rigidity is provided by horizontal struts between the vertical legs, whereas in the cross-braced type rigidity is provided by diagonal cross-bracing between the legs.

Copies of catalog data andother technical data shall be submitted with the falsework Shop Drawing submittals to verify the load-carrying capacity, deflection, and manufacturers installation requirements of any manufactured product or device proposed for use. Upon request by the Engineer, the Contractor shall submit manufacturer certified test reports and results showing load capacity, deflection, test installation conditions, and identify associated components and hardware for shoring tower systems or other devices. In addition to manufacturer’s requirements, the criteria shown in the following sections for manufactured proprietary shoring tower systems and devices shall be complied with when preparing falsework Shop Drawing submittals, calculations, and installing these shoring tower systems and devices as falsework.

Alternative criteria and/or systems may be allowed if a written statement on the manufacturer’s letter head, signed by the shoring or device manufacturer (not signed by a material Supplier or the Contractor) is submitted to the Engineer for review and addresses the following:

In any case where the falsework Shop Drawing submittals detail a manufactured product and the manufacturer’s safe working load, load versus deflection curves, factor of safety, and installation requirements cannot be found in any catalog, the Engineer may require load testing per Section 6-02.3(17)H to verify the safe working load and deflection characteristics.

For all tower systems, tower leg loads shall not exceed the limiting values under any loading condition or sequence. Frame extensions and any reduced capacity shall be shown in the falsework Shop Drawing submittals. Screw jacks shall fit tight in the leg assemblies without wobble. Screw jacks shall be plumb and straight. Shoring towers shall be installed plumb, and load distribution beams shall be arranged such that vertical loads are distributed to all legs for all successive concrete placements. There shall be no eccentric loads on shoring tower heads unless the heads have been designed for such loading. Shoring towers shall remain square or rectangular in plan view and shall not be skewed. There shall be no interchanging of parts from one manufactured shoring system to another. Bent or faulty components shall not be used.

For manufactured shoring towers that allow ganging of frames, the number of ganged frames shall be limited to one frame per opposing side of a tower, and the total number of legs per ganged tower shall not exceed eight legs. Ganged frames shall be installed per the manufacturer’s published standards using the manufacturer’s components. Other gang arrangements shall not be used.

For manufactured steel shoring tower systems, the Contractor shall have bracing designed and installed for horizontal loads and falsework overturning per Section 6-02.3(17)B. Minimum bracing criteria and allowable leg loads are described in the following paragraphs.

All shoring tower systems and bracing shall be thoroughly inspected by the Contractor for plumb vertical support members, secure connections, and straight bracing members immediately prior to, at intervals during, and immediately after every concrete placement. For manufactured shoring tower systems, the maximum allowable deviation from the vertical is 1/8-inch in 3 feet. If this tolerance is exceeded, concrete shall not be placed until adjustments have brought the shoring towers within the acceptable tolerance.

Cross-Braced Type Base Frames:

The maximum allowable load per leg for cross-braced type base frame shoring is limited by the height of the extension frame and the type of screw jack (swivel or fixed head) used at the top of the frame. The maximum load on one leg of a frame shall not exceed four times the load on the other leg under any given loading condition or sequence. The maximum load on one of the two frames making up a tower shall not exceed four times the load on the opposite frame under any given loading condition or sequence. If swivel-head screw jacks are used, the allowable leg loads shall not exceed that shown in the following table:

Maximum Allowable Leg Load in Pounds
Extension Frame Height	2'-0"	3'-0"	4'-0"	5'-0"
Screw height 12" or less	11,000	11,000	10,000	9,400
Screw height exceeds 12"	8,200	8,200	8,000	7,800

If fixed-head screw jacks are used at the top of the extension frame, the maximum allowable load per leg shall be 11,000 pounds for all extension frame heights up to five feet with screw jack height extensions of 12 inches or less. Fixed- head screw jacks exceeding 12 inches shall use the values in the table above. Screw jack extensions shall not exceed the manufacturer’s published recommendations. Extension frames shall be braced. Side cross-braces are required for extension heights up to 2 feet 0 inches. Both side and end cross-braces are required from over 2 feet 0 inches to 5 feet 0 inches extension heights.

Supplemental bracing shall be installed on shoring towers 20 feet or more in height and shall connect rows of towers to each other so rows of frames are continuously cross-braced in one plane. Supplemental bracing shall be installed as follows:

The bracing shall be fastened securely to each frame leg and shall be located within 6 inches of the frame member intersections. The ends of diagonal braces shall not be attached to shoring frames at locations where towers have little or no load. Diagonal brace ends shall be attached to tower frames near the top and bottom at locations where significant gravity load is maintained throughout all construction sequences, such as directly below box girder outside webs, thus precluding lift-off due to the vertical component of the brace reaction. Supplemental bracing shall be shown in the falsework Shop Drawingsubmittal. The connection details, including the method of connection and exact location of the connecting devices, shall be in accordance with the manufacturer’s recommendations and shall be shown in the falseworkShop Drawing submittals.

Ladder Type Base Frames:

Ladder type base frame shoring shall be limited to the following maximum loads and conditions, regardless of any conflicting information which may be found in manufacturer’s catalogs or brochures:

Maximum allowable leg loads as shown above shall apply when fixed-head screw jacks are used, or when swivel-head jacks are used at either the top or bottom of the tower. A screw jack extension shall not exceed 12 inches. Swivel-head screw jacks shall not be used at both the top and bottom of ladder-type frames. For any combination of ladder-type base frames or base frames with staff extensions, the total height of the shoring shall not exceed 20 feet, including screw jack extensions.

When roadway grade, soffit profile, or superelevation exceeds 4 percent slope for heights of shoring towers 20 feet or less, a continuous brace parallel to the slope shall be attached to each staff extension or screw jack of the tower within 6 inches of the top. These braces shall be attached per conditions described previously for cross-braced frames.

Intermediate Strength Shoring:

Steel shoring, consisting of cross-braced tubular members capable of carrying up to 25 kips per tower leg, is considered intermediate strength shoring. The use of a 25-kip type falsework shoring system shall meet the following conditions and limitations:

The use of 25-kip shoring, when designed and erected in conformance with the above criteria, is acceptable for tower heights up to five frames plus a fully-extended extension frame plus the maximum allowable screw-jack adjustment. For any proposed use exceeding this limiting height, the Contractor shall submit a statement signed by the shoring manufacturer covering the specific installation. The statement shall provide assurance that the shoring shall carry the loads to be imposed without overstressing any shoring component or reducing the required safety factor.

Heavy-Duty Shoring Systems:

Shoring capable of carrying up to 100 kips per tower leg is considered heavy duty shoring. The following criteria applies to these systems.

If tower legs, including any extension unit, are utilized as single-post shores braced in one direction only, the shores shall be analyzed as individual steel columns.

If the total height of the shoring does not exceed the height of a single tower unit, including any extension unit, and if both the base and extension units are fully braced in both directions in accordance with the manufacturer’s recommendations, individual tower legs may be considered as capable of carrying the safe working load recommended by the manufacturer without regard to the load on adjacent legs.

If the shoring consists of two or more units stacked one above the other, either with or without an extension unit, the differential leg loading within a given tower unit shall not exceed the following limitations:

Differential Leg Loading
Maximum load on any leg in the tower unit	Maximum to Minimum load ratio
10 kips or less	10 to 1
10 kips to 50 kips	6 to 1
50 kips to 75 kips	5 to 1
75 kips or more	4 to 1

A complete stress analysis of steel beams used as continuous caps over two or more tower units shall be performed to determine the effect of continuity on tower leg loads. Resulting moment shear shall be added to or subtracted from the simple beam reaction to obtain the actual leg load and may produce a significant load differential.

Heavy-duty shoring shall be diagonally braced or otherwise externally supported at the top unless the towers are stable against overturning as defined in Section 6-02.3(17)B. When designing external bracing, including cable bracing, attention shall be given to the bracing connection to the falsework. Connections shall be designed to transfer horizontal and vertical forces from the falsework to the bracing system without overstressing any tower component. All external bracing, attachment locations, and connection details shall be shown in the falsework Shop Drawing submittals.

All stringers, beams, joists, and roadway slab support shall be designed for the design loads, deflections, and allowable stresses described in the preceding Sections 6-02.3(17)B , 6-02.3(17)C, and 6-02.3(17)D and for the following conditions.

At points of support, stringers, beams, joists, and trusses shall be restrained against rotation about their longitudinal axis. The effect of biaxial bending shall be investigated in all cases where falsework beams are not set plumb and the structure cross-slope exceeds 3 percent.

For box girder and T-beam bridges, the centerline of falsework beams or stringers shall be located within 2 feet of the bridge girder stems and preferably directly under the stems or webs. Stringers supporting formwork for concrete box girder and T-beam slab overhangs shall be stiff enough so that the differential deflection due to the roadway slab pour is no more than 3/16 inch between the outside edge of the roadway slab and the exterior web even if camber strips can compensate for the deflection.

Friction shall not be relied upon for lateral stability of beams or stringers. If the compression flange of a beam is not laterally restrained, the allowable bending stress shall be reduced to prevent flange buckling. If flange restraint is provided and since it is impossible to predict the direction in which a compression flange buckles, positive restraint shall be provided in both directions. Flange restraint shall be designed for a minimum load of two percent of the calculated compression force in the beam flange at the point under consideration.

Camber strips shall be used to compensate for falsework take-up and deflection, vertical alignment, and the anticipated structure dead load deflection shown in the camber diagram on the Drawings. Camber is the adjustment to the profile of a load-supporting beam or stringer so that the completed structure shall have the lines and grades shown on the Drawings. The dead load camber diagram shown on the Drawings is the predicted Structure dead load deflection due to self weight. This dead load camber shall be increased by:

Camber strips shall be fastened by nailing to the top of wood members, or by clamping or banding in the case of steel members. Camber strips shall have sufficient contact bearing area to prevent crushing under total load. As a general rule, camber strips are not required unless the total camber adjustment exceeds 1/4-inch for exterior falsework stringers and 1/2-inch for interior stringers.

On concrete box girder structures, the forms supporting the roadway slab shall rest on ledgers or similar supports and shall not be supported from the bottom slabexcept as the following provides. The form supports shall be fastened within 18 inches of the top of the web walls, producing a clear span between web walls. The Roadway slab forms may be supported or posted from the bottom slab if allthe following conditions are met:

The falsework and forms on concrete box girder structures supporting a sloping web and deck overhang shall consist of a lateral support system. The support system shall be designed to resist all rotational forces acting on the stem, including those caused by the placement of deck slab concrete, roadway deck formwork weight, finishing machine, and other live loads. Stem reinforcing steel shall not be stressed by the construction of the roadway deck slab placement. Overhang brackets shall not be used for the support of roadway slab forms from sloping web concrete box girder bridges.

Deck slab forms between girders or webs shall be constructed such that there is no differential settlement relative to the girders. The support systems for form panels supporting concrete deck slabs and overhangs on girder bridges, such as steel plate girders and prestressed girders, shall be designed as falsework. Falsework supporting deck slabs and overhangs on girder bridges shall be supported directly by the girders so that there shall be no differential settlement between the girders and the deck forms during placement of deck concrete.

All falsework bracing systems shall be designed to resist the horizontal design load in all directions with the falsework in either the loaded or unloaded condition. All bracing, connection details, specific locations of connections, and hardware used shall be shown in the falsework Shop Drawing submittals. Falsework diagonal bracing shall be thoroughly analyzed with particular attention given to the connections. The allowable stresses in the diagonal braces may be controlled by the joint strength or the compression stability of the diagonal. Timber bracing for timber falsework bents shall have connections designed per Section 6-02.3(17)J. Any damaged cross-bracing, such as split timber members, shall be replaced. Steel strapping shall avoid making sharp angles or right-angle bends. A means of preventing accidental loss of tension shall be provided for steel strapping. See Sections 6-02.3(17)B, 6-02.3(17)C and 6-02.3(17)D for design loads and allowable stresses.

Bracing shall not be attached to concrete traffic barrier, guardrail posts, or guardrail.

To prevent falsework beam or stringer compression flange buckling, cross-bracing members and connections shall be designed to carry tension as well as compression. All components, connection details and specific locations shall be shown in the falsework ShopDrawing submittals. Bracing, blocking, struts, and ties required for positive lateral restraint of beam flanges shall be installed at right angles to the beam in plan view. If possible, bracing in adjacent bays shall be set in the same transverse plane. However, if because of skew or other considerations, it is necessary to offset the bracing in adjacent bays, the offset distance shall not exceed twice the depth of the beam.

All falsework and bracing shall be inspected by the Contractor for plumbness of vertical support members, secure connections, tight cables, and straight bracing members immediately prior to, during, and immediately after every concrete placement.

Bracing shall be provided to withstand all imposed loads during erection of the falsework and all phases of construction for falsework adjacent to any roadway, sidewalk, or railroad track which is open to the public. All details of the falsework system thatcontribute to horizontal stability and resistance to impact, including the bolts in bracing, shall be installed at the time each element of the falsework is erected and shall remain in place until the falsework is removed. The falsework Shop Drawing submittals shall show provisions for any supplemental bracing or methods to be used to conform to this requirement during each phase of erection and removal. Wind loads shall be included in the design of such bracing or methods. Loads, connections, and materials for falsework adjacent to Roadways, shall also be in accordance with Section 6-02.3(17)D.

Cable or Tension Bracing Systems:

All elements of the bracing system shall be shown in the falsework Shop Drawing submittals when cables, wire rope, steel rod, or other types of tension bracing members are used as external bracing to resist horizontal forces, or are used as temporary bracing to support bents while falsework is being erected or removed adjacent to Traffic. Bracing shall not be attached to concrete traffic barrier, guardrail posts, or guardrail. Any damaged bracing, such as frayed and kinked guying systems, shall be immediately replaced. Wire rope shall not make a sharp angle bend or a right-angle bend. A means of preventing accidental loss of tension in the wire rope shall be provided.The following information shall be submitted to the Engineer for review:

Copies of manufacturer’s catalog or brochure showing technical data pertaining to the type of cable to be used shall be furnished with the falsework Shop Drawing submittal. Technical data shall include the cable diameter, the number of strands and the number of wires per strand, ultimate breaking strength or recommended safe working strength, and any other information as may be needed to identify the cable.

In the absence of sufficient technical data to identify the cable, or if it is old and obviously worn, the Contractor shall perform cable breaking tests to establish the safe working load for each reel of cable furnished. For static guy cable the minimum factor of safety shall be 3 to 1. The Contractor shall notify the Engineer at least 2 Working Days in advance for witnessing these tests.

When cable bracing is used to prevent the overturning of heavy-duty shoring, attention shall be given to the connections by which forces are transferred from the shoring to the cables. Cable restraint shall be designed to act through the cap system to prevent the inadvertent application of forces which the shoring is not designed to withstand. Cables shall not be attached to any tower component.

Cable splices made by lapping and clipping with “Crosby” type clamps shall not be used. Other splicing methods may be used. Cable strength shall be verified by a load testat each location where the cable is spliced.

When cables are used as external bracing to resist overturning of a falsework system, the horizontal load to be carried by the cables shall be calculated as follows:

The maximum allowable cable design load shall be determined using the following criteria and the tables immediately following:

Cable connectors shall be designed in accordance with criteria shown in the following tables “Efficiency of Wire Rope Connections” and “Applying Wire Rope Clips”. Cable safe working loads are provided in table “Wire Rope Capacities”.

Efficiency of Wire Rope Connections (As compared to Safe Loads on Wire Rope)
Type of Connection	Connector Efficiency
Wire Rope	100%
Sockets – Zinc Type	100%
Wedge Sockets	70%
Clips – Crosby Type with Thimble	80%
Knot and Clip (Contractors Knot)	50%
Plate Clamp-Three Bolt Type with Thimble	80%
Spliced Eye and Thimble:
1/4" and smaller	100%
3/8" to 3/4"	95%
7/8" to 1"	88%
1-1/8" to 1-1/2"	82%
1-5/8" to 2"	75%
2-1/8" and larger	70%

WIRE ROPE CAPACITIES Safe Load in Pounds for New Plow Steel Hoisting Rope 6 Strands of 19 Wires, Hemp Center (Safety Factor of 6)
Diameter Inches	Weight Lbs/Ft	Safe Load Lbs
1/4	0.10	1,050
5/16	0.16	1,500
3/8	0.23	2,250
7/16	0.31	3,070
1/2	0.40	4,030
9/16	0.51	4,840
5/8	0.63	6,330
3/4	0.95	7,930
7/8	1.29	10,730
1	1.60	15,000
1-1/8	2.03	18,600
1-1/4	2.50	23,000
1-3/8	3.03	25,900
1-1/2	3.60	30,700
1-5/8	4.23	35,700
1-3/4	4.90	41,300

Applying Wire Rope Clips:

The only correct method of attaching U-bolt wire rope clips to rope ends is to place the base (saddle) of the clip against the live end of the rope, while the “U” of the bolt presses against the dead end.

The clips are usually spaced about six rope diameters apart to give adequate holding power. A wire-rope thimble shall be used in the loop eye to prevent kinking when wire rope clips are used. The correct number of clips for safe application, and spacing distances, are as follows:

Number of Clips and Spacing for Safe Application
	Number of Clips
Improved Plow Steel Rope Diameter (Inches)	Drop Forged	Other Material	Min. Spacing (Inches)
3/8	2	3	3
1/2	3	4	3-1/2
5/8	3	4	4
3/4	4	5	4-1/2
7/8	4	5	5-1/4
1	5	6	6
1-1/8	6	6	6-3/4
1-1/4	6	7	7-1/2
1-3/8	7	7	8-1/4
1-1/2	7	8	9

Anchor Blocks:

Concrete anchor blocks and connections used to resist forces from external bracing shall be shown in the falsework Shop Drawing submittal. Concrete anchor blocks shall be proportioned to resist both sliding and overturning. When designing anchor block stability, the weight of the anchor block shall be reduced by the vertical component of the cable or brace tension to obtain the net or effective weight to be used in the anchorage computations. The coefficient of friction assumed in the design shall not exceed the following:

Setting	Friction Coefficient
Anchor block set on sand	0.40
Anchor block set on clay	0.50
Anchor block set on gravel	0.60
Anchor block set on pavement	0.60

Note: Multiply the friction coefficient by 0.67 if it is likely the supporting material is wet or shall become wet during the construction period.

The method of connecting the cable or brace to the anchor block is part of the anchor block design. The connection shall be designed to resist both horizontal and vertical forces.

Temporary Bracing for Bridge Girders:

Bridge girders (such as steel plate girders and prestressed girders) shall be braced and tied to resist forces applied during constructionthat would cause rotation or torsion in the girders. Falsework support brackets or braces shall not be welded to structural steel members or reinforcing steel.

On prestressed girder spans, the Contractor shall install cross-bracing between girders at each end and midspan to prevent lateral movement or rotation. This bracing shall be placed immediately after erection of the girders. The bracing shall not be removed until the diaphragms or the deck have been placed and cured for a minimum of 24 hours.

When deck overhang or the distance from the centerline of the exterior girder, or outside girder of a staged construction, to the near edge of the Roadway slab on a prestressed girder span exceeds the distances listed in the tablethat follows,the Contractor shall provide extra bracing for the exterior girder at the midpoint between diaphragms (or at more frequent intervals). This bracing shall include:

(1) a cross-tie connecting the top flange of each exterior girder with its counterpart on the other side, and

(2) braces between the bottom flanges and top flanges of all girders.

Girder Series	Distance in Inches
W42G	30
W50G	42
W58G	63
W74G	66

If a concrete finishing machine is supported at the outside edge of the slab, the Contractor shall account for its added weight in the design of bracing.

Roadway deck forming systems may require bracing or ties between girders for the girder to adequately support the form loading. When braces, struts, or ties are required, they shall be designed and detailed by the Contractor in accordance with Section 6-02.3(16)A and shall be shown in the falsework/formwork Shop Drawing submittal to the Engineer for review. These braces, struts, and ties shall be furnished and installed by the Contractor at no additional cost to the Owner.

The Contractor shall establish the load capacity and deflection (or settlement) of all friction collars and clamps, brackets, hangers, saddles, sand jacks, and similar devices.The Contractor shall utilize an independent testing laboratory accredited in accordance with ASTM E 1595 and approved by the Engineer to establish these values. Laboratory tests shall use the same materials and design that shall be used on the Project. Test loads shall be applied to the device in the same manner that the device is to experience loading on the Project. Any bolts or threaded rods used with the device shall be identified as to diameter, length, type, grade, and torque. Any wedges, blocks, or shims used with the device on the Project shall also be tested with the device. Any adjustable jack system used as a part of a device shall be tested with the device and shall have its maximum safe working extended height identified. Devices shall not be tested in contact with the permanent structure. Independent members with the same properties as the permanent structure shall be used to test device connections.

At least fourteen (14) days prior to the test, the Contractor shall submit a test procedure and scale drawing for the Engineer’s review showing how the device is to be tested and how data is to be collected. The Contractor shall provide the Engineer at least 2 Working Days advance notice for an opportunity to witness these tests.

The approved independent testing laboratory identified in this Specification Section shall provide a certified test report which shall be signed and dated. The test report shall:

1. clearly identify the device tested including trademarks and model numbers;

2. identify all parts and materials used, including grade of steel, or lumber, member section dimensions;

3. show location, size, and the maximum tested extended height of any adjustable jacks;

4. indicate condition of materials used in the device;

5. indicate the size, length and location of all welds; and

6. indicate how much torque was used with all bolts and threaded rods.

The report shall also describe:

a. how the device was tested,

b. report the results of the test,

c. provide a scale drawing of the device showing the location(s) of where deflections or settlements were measured, and

d. show where load was applied.

Deflections or settlements shall be measured at each load increment and the results shall be clearly graphed and labeled. Prior to installation of falsework devices named in this Specification Section, the Contractor shall submit the certified test reports to the Engineer for review.

The safe working load for shop manufactured devices named in this section shall be derived by dividing the ultimate strength by a safety factor of 2.0. The safe working load for field fabricated or field modified devices (including the use of timber blocks or wedges with the device) shall be determined by dividing the ultimate strength by a safety factor of 3.0. Working load shall include weights of all successive concrete placements, falsework, forms, all load transfer that takes place during post-tensioning, and any live loads; such as workers, roadway finishing machines, and concrete delivery systems. The maximum allowable free end deflection of deck overhang brackets with combined dead and live working loads applied shall be 3/16 inch even though deflection may be compensated for by pre-cambering or setting the elevations high. The Contractor shall comply with all manufacturer’s specifications, including those relating to bolt torque, cleaning and oiling of parts, and the reuse of material. Devices that are deteriorated, bent, warped or have poorly fitted connections or welds, shall not be installed.

Formwork accessories such as form ties, form anchors, form hangers, anchoring inserts, and similar hardware shall be specifically identified in the formwork Shop Drawings. The identification shall include the name and size of the hardware, the manufacturer, the safe working load, and the factor of safety. The grade of steel shall also be indicated for threaded rods, coil rods, and similar hardware. Wire form ties taper ties and welding or clamping formwork accessories to Drawings reinforcing steel shall not be used. Driven types of anchorages for fastening forms or form supports to concrete, and Contractor fabricated “J” hooks shall not be used. Field drilling of holes in prestressed girders is not allowed.

1Safety factors are based on ultimate strength of the formwork accessory.

The bearing area of external holding devices shall be adequate to prevent excessive bearing stress on form lumber. Form ties and form hangers shall be arranged symmetrically on the supporting members to minimize twisting or rotation of the members. Form tie elongation shall not exceed the allowable deflection of the wale or member that it supports. Inserts, bolts, coil rods, and other fasteners shall be analyzed and designed for appropriately combined bending, shear, torsion, and tension stresses. The formwork shall not be attached to Contract Drawing rebar or rebar cages. However, the Contractor may install additional reinforcing steel for formwork anchorage.

Frictional resistance shall not be considered as contributing to the stability of any connection or connecting device, except those designed as friction connectors such as U-bolt friction-type connectors.

Form anchors and anchoring inserts shall be designed considering concrete strength at time of loading, available embedment, location in the member, and any other factors affecting their working strength, and shall be installed in concrete per the manufacturer’s published requirements. Form anchors and anchoring inserts embedded in previous concrete placements shall not be loaded until the concrete has reached the required design strength. The required design strength of concrete for loading of an anchor shall be shown in the formwork Shop Drawing if it is assumed that the anchor is to be loaded before the concrete has reached its 28 day strength.

Installation of permanent concrete inserts, such as form ties hangers, or embedded anchor assemblies, shall permit removal of all metal to at least 1/2-inch below the concrete surface. Holes shall be patched in accordance with Section 6-02.3(14). During removal of the outer unit, the bond between the concrete and the inner unit or rod shall not be broken.

Timber connections shall be designed in accordance with the methods, stresses, and loads allowed in the Timber Construction Manual, Third Edition by the American Institute of Timber Construction (AITC). Timber falsework and formwork connections shall be designed using wet condition stresses for all installations West of the Cascade Range crest line and by criteria provided in the following sections. Frictional resistance shall not be considered as contributing to the stability of any timber connection.

Bolted Connections:

Tabulated values in the AITC Timber Construction Manual-Third Edition are based on square posts. For a round post or pile, the main member thickness shall be the side of a square post having the same cross-sectional area as the round post used.

The AITC Table 6.20 for Douglas Fir-Larch bolt Group 3 and for Hem-Fir bolt Group 8 show design values for bolts to be used when the load is applied either parallel or perpendicular to the direction of the wood grain. When the load is applied at an angle to the grain, as is the case with falsework bracing, the design value for the main member shall be obtained from the Hankinson formula shown in the AITC manual.

Design values in the AITC Table 6.20 apply only to three member joints (bolt in double-shear) in which the side members are each 1/2 the thickness of the main member. This joint configuration is not typical of bridge falsework where side members are usually much smaller than main members. For two member joints (single shear bolt condition), the AITC Table 6.20 values shall be adjusted by a single shear load factor as follows:

Except for connections in falsework adjacent to or over railroads or Roadways, threaded rods and coil rods may be used in place of bolts of the same diameter with no reduction in the tabulated values. At openings for roadways and railroads, all connections shall be bolted using 5/8-inch diameter or larger through bolts.

Bolt holes shall be a minimum 1/32-inch to a maximum 1/8-inch larger than the bolt diameter. A washer not less than a standard cut washer shall be installed between the wood and the bolt head and between the wood and the nut to distribute the bearing stress under the bolt head and nut and to avoid crushing the fibers. In lieu of standard cut washers, metal plates or straps with dimensions at least equal to that of a standard cut washer may be substituted.

When steel bars or shapes are used as diagonal bracing, the tabulated design values shown in AITC Table 6.20 for the main members loaded parallel to grain (P value) are increased 75 percent for joints made with bolts 1/2-inch or less in diameter, 25 percent for joints made with bolts 1-1/2-inches in diameter, and proportionally for intermediate diameters. No increase in the tabulated values is allowed for perpendicular-to-grain loading (Q value).

Clearance requirements for end, edge, and bolt spacing distance shall be as shownin the following.All distances are measured from the end or side of the wood member to the center of the bolt hole. For members which are subject to load reversals, the larger controlling distances shall be used for design. For parallel-to-grain loading, the minimum distances for full design load:

For perpendicular-to-grain loading, the minimum distance for full design load:

Minimum clearance (spacing) between adjacent bolts in a row shall be 4 times the bolt diameter, measured center-to-center of the bolt holes.

When more than two bolts are used in a line parallel to the axis of the side member, additional requirements shall be followed as shown in the AITC manual.

Lag Screw Connections:

Design values for lag screws subject to withdrawal loading are found in AITC Table 6.27. Values for wood having a specific gravity of 0.51 for Douglas Fir-Larch or 0.42 for Hem-Fir shall be assumed when using the table. The withdrawal values are in pounds per inch of penetration of the threaded part of the lag screw into the side grain of the member holding the point, with the axis of the screw perpendicular to that member. The maximum load on a given screw shall not exceed the allowable tensile strength of the screw at the root section.

AITC recommends against subjecting lag screws to end-grain withdrawal loading. However, if this condition cannot be avoided, the design value shall be 75 percent of the corresponding value for withdrawal from the side grain.

Values in the Group II wood species column shall be used for Douglas Fir-Larch and the Group III wood species column shall be used for Hem-Fir. When the load is applied at an angle to the grain, as is the case with falsework bracing, the design value shall be obtained from the Hankinson formula shown in the AITC manual.

When lag screws are subjected to a combined lateral and withdrawal loading, as would be the case with longitudinal bracing when the falsework bents are skewed, the effect of the lateral and withdrawal forces shall be determined separately. The withdrawal component of the applied load shall not exceed the allowable value in withdrawal. The lateral component of the applied load shall not exceed the allowable lateral load value.

Lag screws shall be inserted in lead holes as follows:

Drift Pin and Drift Bolt Connections:

When drift pins or drift bolts are used, the required length and penetration shall be determined using the following criteria:

The lateral load-carrying capacity of drift pins and drift bolts driven into the side grain of a wood member shall be limited to 75 percent of the design values for a common bolt of the same diameter and length in the main member. For drift pin connections, the pin penetration into the connected members shall be increased to compensate for the absence of a bolthead and nut. For drift bolts or pins driven into the end grain of a member, the lateral load-carrying capacity shall be limited to 60 percent of the allowable side grain load (perpendicular to grain value) for an equal diameter bolt with nut. To develop this allowable load the drift bolt or pin shall penetrate at least 12 diameters into the end grain. To fully develop the allowable load of the drift bolts or pins, they shall be driven into pre-drilled holes, 1/16-inch less in diameter than the drift pin or bolt diameter.

The criteria shown in the AITC Timber Construction Manual-Third Edition shall apply to drift bolt or pin connection allowable loads for the following conditions:

Nailed and Spiked Joints:

Joints using nails or spikes shall conform to the provisions of AITC. For side grain withdrawal, the values in AITC Table 6.35 for wood having a specific gravity of 0.51 for Douglas Fir-Larch and a specific gravity of 0.42 for Hem-Fir shall be used. End grain withdrawal shall not be used. For lateral loading, the values in AITC Table 6.36 for wood species Group II for Douglas Fir-Larch and wood species Group III for Hem-Fir shall be used. Diameters listed in the tables apply to fasteners before application of any protective coating.

When more than one nail or spike is used in a joint, the total design value for the joint in withdrawal or lateral resistance shall be the sum of the design values for the individual nails or spikes.

The tabulated design values for lateral loads are valid only when the nail penetrates into the main member at least 11 diameters for Douglas Fir-Larch and 13 diameters for Hem-Fir. Note that the values are maximum values for the type and size of fastener shown. The tabulated values shall not be increased even if the actual penetration is exceeded.

When main member penetration is less than 11 diameters for Douglas Fir-Larch and 13 diameters for Hem-Fir, the design value shall be determined by straight-line interpolation between zero and the tabulated load, except that penetration shall not be less than 1/3 of that specified.

Double-headed or duplex nails used in falsework and formwork construction are shorter than common wire nails or box nails of the same penny weight. They have less penetration into the main member and therefor their load-carrying capacity shall be adjusted accordingly.

Nail and spike minimum spacing in timber connections shall be as follows:

Allowable values for withdrawal and lateral load resistance are reduced when toe nails are used in accordance with the following:

Toe nails are recommended to be driven at an approximate angle of 30 degrees with the piece and started approximately 1/3 of the length of the nail from the end or side of the piece.

Timber Connection Adjustment for Duration of Load:

Tabulated values for timber fasteners are for normal duration of load and may be increased for short duration loading, except for connections used in falsework and formwork for post tensioned structures and staged construction sequences. Duration of load adjustment for timber connections shall not be allowed for all post tensioned structures and for staged construction sequences where delayed and/or staged loading occurs for any type of concrete structure. The adjustment for duration of load as described in this section applies only to design values for timber connectors, such as nails, bolts, and lag screws. Allowable stresses for timber and structural steel components used in the connection, as described in Section 6-02.3(17)C, are maximums and thus shall not be increased.

Tabulated values for nails, bolts, and lag screws may be adjusted by the following duration-of-load factors:

Elements of this section shall be designed for the loads, allowable stresses, deflections, and conditions which pertain from other subsections of Section 6-02.3(17).

Forms battered or inclined over the concrete tend to uplift as concrete is placed and shall have positive anchorage or counterweights designed to resist uplift and shall be shown in the formwork Shop Drawing submittal. Where the concrete pouring sequence causes fresh concrete to be significantly higher along one side of tied forms than the opposite side, a positive form anchorage system shall be designed capable of resisting the imbalance of horizontal thrust, and prevent the dislocation and sliding of the entire form unit.

Wooden forms shall be faced with smooth sanded, exterior plywood. This plywood shall meet the requirements of the National Bureau of Standards, U.S. Product Standard PS 1, and the Design Specification of the American Plywood Association (APA). Each full sheet shall bear the APA stamp. The Contractor shall list in the formwork Shop Drawing submittal the grade and class of plywood. The Contractor may use plywood that does not carry the APA stamp if the plywood manufacturer submits a Manufacturer's Certificate of Compliance stating the plywood meets or exceeds the requirements of these Specifications for plywood. Plywood panels stamped “shop” or “shop cutting” shall not be used.

Plyform is an APA plywood specifically designed and manufactured for concrete forming. Plyform differs from conventional exterior plywood grades in strength and the exterior face panels are sanded smooth and factory oiled. Likewise, there is a significant difference between grades designated Class 1, Class 2, and Structural I Plyform.

The grades of plywood for various form applications shall be as follows:

Form joints on an exposed surface shall be in a horizontal or vertical plane. But in wingwalls and box girders, side form joints shall be placed at right angles and parallel to the Roadway grade. Joints parallel to studs or joists shall be backed by a stud or joist. Joints at right angles to studs and joists shall be backed by a stud or other equal performance backing. Perpendicular backing is not required if studs or joists are spaced:

The face grain of plywood shall run perpendicular to studs or joists unless shown otherwise on thereviewed Contractor’s formwork Shop Drawings. Proposals to deviate from the perpendicular orientation shall be accompanied by supporting calculations of the stresses and deflections.

Forming for all exposed curved surfaces shall follow the shape of the curve shown on the Drawings and shall not be chorded except as follows. On any retaining wall that follows a horizontal circular curve, the wall stems may be a series of short chords if:

Where architectural treatment is required, the angle point for chords in wall stems shall fall at vertical rustication joints.

For exposed surfaces of abutments, wingwalls, piers, retaining walls, and columns, the Contractor shall build forms of plywood at least 3/4-inch thick with studs no more than 12 inches on center. Deflection of the plywood, studs, or wales shall never exceed 1/500 of the span (or 1/360 of the span for unexposed surfaces, including the bottom of the deck slab between girders).

All form plywood shall be at least 1/2-inch thick except on sharply curved surfaces. There, the Contractor may use 1/4-inch plywood if it is backed firmly with heavier material.

Round columns or rounded pier shafts shall be formed with a self-supporting metal shell form or form tube that leaves a smooth, non-spiraling surface. Wood forms are not permitted.

Metal forms shall not be used elsewhere unless an acceptable surface can be demonstrated to the Engineer. Failure to provide and acceptable surface at any time will result in the Engineer requiring the Contractor to not use metal forms.If permitted to use a combination of wood and metal in forms, the Contractor shall coat the forms so that the texture produced by the wood matches that of the metal. Aluminum shall not be used for metal forms.

For design purposes, the Contractor shall assume that on vertical surfaces concrete exerts 150 pounds of pressure per square foot per foot of depth. However, when the depth is reached where the rate of placement controls the pressure, the following table applies:

Rate of Placing Feet per Hour	Pressure, Pounds per Square Foot for Temperature of Concrete as Shown
	60 °F	70 °F and above
2	470	375
3	640	565
4	725	625
5	815	690
6	900	750
7	990	815
8	1,075	875
9	1,165	935
10	1,250	1,000
15	1,670	1,300

The pressures in the above table have been increased to provide an allowance for the vibration and impact.

Horizontal surfaces shall support a pressure of 160 pounds per square foot for each foot of concrete height.

All exposed corners shall be beveled 3/4-inch. However, traffic barriers, footings, footing pedestals and seals need not be beveled unless the Contractrequires it.

All forms shall be as mortartight as possible with no water standing in them as the concrete is placed.

The Contractor shall apply a parting compound on forms for exposed concrete surfaces. This compound shall be a chemical release agent that permits the forms to separate cleanly from the concrete. The compound shall not penetrate or stain the surface and shall not attract dirt or other foreign matter. After the forms are removed, the concrete surface shall be dust-free and have a uniform appearance. The Contractor shall apply the compound at the manufacturer’s recommended rate to produce a surface free of dusting action and yet provide easy removal of the forms.

If an exposed concrete surface is to be sealed, the release agent shall not contain silicone resin. Before applying the agent, the Contractor shall submit to the Engineer a Manufacturer’s Certificate of Compliance stating whether the resin in the base material is silicone or non-silicone.

The Contractor shall submit to the Engineer a sample and catalog cut of the parting compound at least 10 Working Days before its use. Approval or nonapproval shall be based on laboratory tests results.

The Engineer may reject any forms that are not able to produce an acceptablesurface.

Forms for concrete placement on all steel structures shall be removable and shall not remain in place. Where needed, the forms shall have openings for truss or girder members. Each opening shall be large enough to leave at least 1-1/2 inches between the concrete and steel on all sides of the steel member after the forms have been removed.

Any form support for a roadway slab that rests on a plate girder flange shall apply the load within 6 inches of the girder web centerline. The Contractor shall not weld any part of the form to any steel member.

If the Engineer permits bolt holes in the web to support form brackets, the holes shall be shop-drilled.The Contractor shall fill the holes with fully torqued AASHTO M 164 bolts per Section 6-03.3(33). Each bolt head shall be placed on the exterior side of the web. There shall be no holes made in the flanges.

Before using any finishing machine, the Contractor shall submit to the Engineer for review, detailed Shop Drawings that show the system proposed to support it. The Contractor shall not attach this (or any other) equipment support system to the sides or suspend it from any girder. The Engineer will not permit such a method if it unduly alters stress patterns or creates too much stress in the girder.

The Contractor shall notify the Engineer not less than 15 Working Days before the anticipated start of each falsework and girder erection operation whenever such falsework or girders reduce clearances available to the public Traffic. Falsework openings shall not be more restrictive to Traffic than shown on the Drawings.

Where the height of vehicular openings through falsework is less than 15 feet 0 inches, a W 12-2 “Low Clearance Symbol Sign” shall be erected on the shoulder in advance of the falsework, and two or more W 12-301 and/or W 12-302 signs shall be attached to the falsework to provide accurate usable clearance information over the entire falsework opening. The posted low clearance shall include an allowance for anticipated falsework girder deflection (rounded-up to the next whole inch) due to design dead load, including all successive concrete pours. W 12-302 signs shall be used to designate prominent clearance restrictions and limits of usable clearance. In addition, where the clearance is less than the legal height limit (14 feet 0 inches), a W 12-2 sign shall be erected in advance of the nearest intersecting Road or wide point in the Road at which a vehicle can detour or turn around. A W 13-501 sign indicating the distance to the low clearance shall be installed below the advance sign. The Engineer will furnish the above noted signs and the Contractor shall erect and maintain them, all in accordance with Sections 1-07.23 and 1-10.

When erecting falsework that restricts overhead clearance above a railroad track, the Contractor shall place restricted overhead clearance signsas soon as the restriction occurs. Sign details are shown in WSDOT Standard Plan no.G-1.

The Contractor shall obtain the Engineer's written approval for the removal of forms or falsework. The Engineer will determine, on the basis of post-placement curing conditions, the exact number of curing days that shall elapse before form removal. The Contractor may request the removal of forms (from the time of the last pour the forms support) as indicated in the table that follows. Both compressive strength and curing days criteria shallbe met if both are listed:

Concrete Placed In	% of Specified Minimum Compressive Strength	Number of Curing Days
Columns, wall faces, mass piers and abutments (except pier caps), traffic and pedestrian barriers, and any other side form not supporting the concrete weight.1	---	3
Pier caps continuously supported.2	60	3
Sidewalks not supported on bridge roadway slabs.2	70	---
Crossbeams, caps, pier caps not continuously supported, struts and top slabs on concrete box culverts, inclined columns and inclined walls.2,3	80	5
Roadway slabs supported on wood or steel stringers or on steel or prestressed concrete girders.2	80	10
Box girders, T-beam girders, and flat-slab Superstructure.2,3	80	14
Arches.2,3	---	21

NOTES 1Where forms do not support the load of concrete.

2Where forms support the load of concrete.

3Where continuous spans are involved, the time for all spans will be determined by the last concrete placed

affecting any span.

Before releasing supports from beneath beams and girders, the Contractor shall remove forms from columns to enable the Engineer to inspect the column concrete.

The Contractor may remove the side forms of footings 24 hours after concrete placement if a curing compound is applied immediately. But this compound shall not be applied to the area of the construction joint between the footing and the column or wall.

The Contractor may remove side forms, traffic barrier forms, and pedestrian barrier forms after 24 hours if these forms are made of steel or dense plywood, an approved water reducing admixtureis used, and the concrete reaches a compressive strength of 1,400 psi before form removal. This strength shall be proved by test cylinders made from the last concrete placed into the form. The cylinders shall be cured according to Field Operating Procedure for AASHTO T 23,

Method 2.

Wet curing shall comply with the requirements of Section 6-02.3(11). The concrete surface shall not become dry during form removal or during the entire curing period.

Before placing forms for traffic and pedestrian barriers, the Contractor shall completely release all falsework under spans.

Before releasing forms under concrete cured at temperatures colder than 50°F, the Contractor shall first prove that the concrete meets desired strength - regardless of the time that has elapsed.

The Engineer may approve leaving in place forms for footings in cofferdams or cribs. This decision will be based on whether removing them would harm the cofferdam or crib and whether the forms are indicated as showing in the finished Structure.

All cells of a box girder structure having permanent access shall have all forms completely removed, including the roadway deck forms. All debris and all projections into the cells shall be removed. Unless otherwiseindicated in the Contract, the roadway slab interior forms in all other cells where no permanent access is available, may be left in place.

Falsework and forms supporting sloping exterior webs shall not be released until the roadway deck and deck overhang concrete has obtained its removal strength and time of cure. Stern reshoring shall not be used.

Open joints shown on the Drawings shall have all forms completely removed, including styrofoam products and form anchors, allowing the completed structure to move freely.

If the Contractor intends to support or suspend falsework and formwork from the bridge Structure while the falsework and formwork is being removed, the Contractor shall submit a falsework and formwork removal plan and calculations in accordance with Section 1-05.3(2)F for review. The falsework and formwork removal plan shall include the following:

All other forms shall be removed, whether they are above or below the level of the ground or water. Sections 6-02.3(7) and 6-02.3(8) govern form removal for concrete exposed to sea water or to alkaline water or soil. The forms inside of hollow piers, girders, abutments, etc. shall be removed through openings provided for that purpose as indicated on the Drawings.

The fabrication, curing and testing of the early cylinders shall be the responsibility of the Contractor. Early cylinders are defined as all cylinders tested in advance of the design age of 28 days whose purpose is to determine the in-place strength of concrete in a structure prior to applying loads or stresses. The Contractor shall retain an accreditedindependent testing laboratory, to be approved by the Engineer, to perform this work. The Contractor shall submit the independent testing laboratory's credentials and experience for doing testing as indicated in this Section to the Engineer at least 5 Working in advance of performing any testing.

The concrete cylinders shall be molded in accordance with Field Operating Procedure for AASHTO T 23 from concrete last placed in the forms and representative of the quality of concrete placed in that pour.

The cylinders shall be cured in accordance with Field Operating Procedure for AASHTO T 23, Method 2. The Engineer may approve the use of cure boxes meeting the requirements of this test method. Special cure boxes to enhance cylinder strength will not be allowed.

The concrete cylinders shall be tested for compressive strength in accordance with AASHTO T 22. The number of early cylinder breaks shall be in accordance with the Contractor’s need and as approved by the Engineer.

The Contractor shall furnish the Engineer with all test results. The test results will be reviewed and approved before any forms are removed. The Contractor shall not remove forms without the approval of the Engineer.

Test laboratories used for this work shall be ASTM or AASHTOaccredited, and shall be approved by the Engineer.

The Contractor shall comply with the following requirements in setting anchor bolts in piers, abutments, or pedestals:

The Contractor shall use rubber cement to bond the lower contact surface of elastomeric bearing pads to the structure.

For all fixed, sliding, or rolling bearings, the Contractor shall:

Grout placement under steel bearings shall comply with Section 6-02.3(20).

Grout shall be a prepackaged grout, mixed, placed, and cured as recommended by the manufacturer, or the grout shall be produced using Type I or Type II Portland cement, fine aggregate Class 1 (see Section 9-03.1(2)C),and water, in accordance with these Specifications.

Grout shall meet the following requirements:

Requirement	Compressive Strength
Test Method	AASHTO T 106
Values	4,000 psi @ 7 days

Grout shall be a workable mix with flowability suitable for the intended application.

If the Contractor elects to use a prepackaged grout, a material sample and laboratory test data from an independent testing laboratory shall be submitted to the Engineer for approval with the request for approval of Material sources (see Section 1-06.1).

If the Contractor elects to use a grout consisting of Type II Portland cement, fine aggregate Class 1, admixture, and water, the mix proportions and laboratory test data from an independent ASTM accredited test laboratory shall be submitted to the Engineer for approval with the request for approval of Material sources.

The Contractor shall first obtain approval of the grout from the Engineer before using the grout.

Field grout cubes shall be made in accordance with WSDOT Test Method 813 for either prepackaged grout or a Contractor provided mix when requested by the Engineer, but not less than per bridge pier or one per day.

The concrete receiving the groutshall firstbe thoroughly cleaned, roughened, and wetted with water to ensure proper bonding. The grout pad shall be cured as recommended by the manufacturer or kept continuously wet with water for three days.

Before placing grout into anchor bolt sleeves or holes, the cavity shall be thoroughly cleaned and wetted to ensure proper bonding.

To grout bridge bearing plates, the Contractor shall:

After all grout under the bearing plate and in the anchor bolt cavities has attained a minimum strength of 4,000 psi, the anchor bolt nuts shall be tightened to snug-tight. “Snug-tight” means either the tightness reached by (1) a few blows from an impact wrench, or (2) the full effort of a man using a spud wrench. Once the nut is snug-tight the anchor bolt threads shall be burred just enough to prevent loosening of the nut.

To drain box girder cells, the Contractor shall provide and install, according to details on the Drawings, short lengths of nonmetallic pipe in the bottom slab at the low point of each cell. The pipe shall have a minimum inside diameter of 4 inches. If the difference in plan elevation is 2 inches or less, the Contractor shall install pipe in each end of the box girder cell.

The Contractor shall use weep holes and gravel backfill that complies with Section 9-03.12(2) to drain fill material behind retaining walls, abutments, tunnels, and wingwalls. To maintain thorough drainage, weep holes shall be placed as low as possible. Gravel backfill shall be placed and compacted as required in Section 2-09.3(1)E. Tiling, French or rock drains, or other drainage devices shall also be installed if indicated on the Drawings.

If underdrains are not installed behind the wall or abutment, all backfill within 18 inches of weep holes shall comply with Section 9-03.12(4). Unless the Contract requires otherwise, all other backfill behind the wall or abutment shall be gravel backfill for walls.

Bridges with a roadway slab made of Portland cement concrete shall remain closed to all Traffic, including construction equipment, until the concrete has reached the 28-day specified compressive strength. This strength shall be determined by testing cylinders made of the same concrete as the roadway and cured under the same conditions. A concrete deck bridge shall never be opened to Traffic earlier than 10 days after the deck concrete was placed and never without written approval of the Engineer.

See Section 6-01.6 for load restrictions on bridges under construction.

The Contractor shall furnish a bar list and bending diagram to the Engineer for review prior to fabrication in accordance with Section 1-05.3(2).

Various steel reinforcing bars, including those in crossbeams, may be shown as straight in the bar list. The Contractor shall bend these bars as required to conform to the configuration of the structure and as detailed on the Drawings.

If the Drawings call for field bending of steel reinforcing bars, the Contractor shall bend them in keeping with the structural configuration indicated in, and in accordance with, the Contract.

Bending steel reinforcing bars partly embedded in concrete shall be done as follows:

Field bending shall not be done:

In field-bending steel reinforcing bars, the Contractor shall:

In applying heat for field-bending steel reinforcing bars, the Contractor shall:

The Contractor shall protect reinforcing steel from all damage. When placed into the structure, the steel shall be free from dirt, loose rust or mill scale, paint, oil, and other foreign matter.

When transporting, storing, or constructing in close proximity to bodies of salt water, plain and epoxy-coated steel reinforcing bar shall be kept in enclosures that provide protection from the elements.

If plain or epoxy-coated steel reinforcing bar is exposed to mist, spray, or fog that may contain salt, it shall be flushed with fresh water prior to concrete placement.

When the Engineer requires protection for reinforcing steel that is to remain exposed for a length of time, the Contractor shall protect the reinforcing steel:

The paint shall have a minimum dry film thickness of 1 mil.

The Contractor shall position reinforcing steel as the Drawings require and shall ensure that the steel is not displaced as the concrete is placed.

When spacing between bars is 1 foot or more, they shall be tied at all intersections. When spacing is less than 1 foot, every other intersection shall be tied. Bundled bars shall be tied together with wires at least every 6 feet. Wire tiesused for tying epoxy-coated reinforcing steel shall be plastic coated. Tack welding is not permitted on reinforcing steel.

Abrupt bends in the steel are permitted only when one steel member bends around another. Vertical stirrups shall pass around main reinforcement or be firmly attached to it.

For slip-formed concrete, the reinforcing steel bars shall be tied at all intersections and crossbraced to keep the cage from moving during concrete placement. Crossbracing shall consist of additional reinforcing steel placed both longitudinally and transversely.

For slip-formed concrete barriers, the vertical dowels protruding from the supporting concrete structure shall be diagonally braced against bending induced by the advancing slip-form. The bracing bars shall be no smaller than No. 5 and shall be extended diagonally from the top of one expansion joint to the bottom of the next expansion joint and shall be securely tied to all intervening dowels. A horizontal top bar shall also be tied to all the dowels.

After reinforcing steel bars are placed in a traffic or pedestrian barrier and prior to slip-form concrete placement, the Contractor shall check clearances and reinforcing steel bar placement. This check shall be accomplished by using a template or by operating the slip-form machine over the entire length of the traffic or pedestrian barrier. All clearance and reinforcing steel bar placement deficiencies shall be corrected by the Contractor before slip-form concrete placement.

Mortar blocks (or other approved devices) shall be used to maintain the concrete coverage required by the Drawings. The mortar blocks shall:

In slabs, each mortar cube shall have either: (1) a grooved top that holds it in place, or (2) an embedded wire that protrudes and is tied to the reinforcing steel. Plastic coated ties shall be used around epoxy-coated bars.

Acceptance of mortar blocks shall be based on testing a set of two specimens. Each pair of specimens shall represent 2,500 or fewer mortar blocks and shall be made of the same mortar as the blocks and cured under the same conditions. The Contractor may either:

In lieu of mortar blocks, the Contractor may use metal or plastic chair supports to hold uncoated bars. Any surface of a metal chair support that is not to be covered by at least 1/2-inch of concrete shall be either:

In lieu of mortar blocks, epoxy-coated reinforcing bars may be supported by either:

Plastic chair supports shall be lightweight, non-porous, and chemically inert in concrete. Plastic chair supports shall have rounded seatings, shall not deform under load at normal temperatures, and shall not shatter or crack under impact loading in cold weather. Plastic chair supports shall be placed at spacings greater than 1 footalong the bar and shall have at least 25% of their gross place area perforated to compensate for the difference in coefficient of thermal expansion between plastic and concrete. The shape and configuration of plastic supports shall permit complete concrete consolidation in and around the support.

In roadway and sidewalk slabs, the Contractor shall place reinforcing steel mats carefully to provide the required concrete cover. A “mat” is 2 layers of steel. Top and bottom mats shall be supported enough to hold both in their proper positions. If No. 4 bars make up the lower layer of steel in a mat, it shall be blocked at not more than 3-foot intervals (or 4-foot intervals for bars No. 5 and larger). Wire ties to girder stirrups shall not be considered as blocking. The Contractor shall add other supports and tie wires to the top mat as neededto provide a rigid mat.

If a bar is indicated as interfering with a bridge drain, it shall be bent in the field to bypass the drain.

Clearances shall be at least:

Reinforcing steel bars shall not vary more than the following tolerances from their position shown on the Drawings:

Members 10 inches or less in thickness	±1/4 in.
Members more than 10 inches in thickness	±3/8 in.
Except:
The distance between the nearest reinforcing steel bar surface and the top surface of the roadway deck slab	+1/4 in.
Longitudinal spacing of bends and ends of bars	±1 in.
Length of bar laps	-1-1/2 in.
Embedded length
No. 3 through No. 11	-1 in.
No. 14 through No. 18	-2 in.
When reinforcing steel bars are to be placed at equal spacing within a plane:
Stirrups and ties	±1 in.
All other reinforcement	±1 bar dia.

Before placing any concrete, the Contractor shall:

The Contractor shall supply steel reinforcing bars in the full lengths the Drawings require.Unless the Engineer approves otherwise in writing, the Contractor shall not change the number, type, or location of splices.

The Engineer may permit the Contractor to use thermal or mechanical splices in place of the method shown on the Drawings if they are of a Contractor submitted and Engineer revieweddesign. Use of a new design may be grantedby the Engineer if:

After a new design has been reviewed, any further changes in detail or material shall require a new submittal for review.

The Contractor shall:

Welding of steel reinforcing bars shall conform to the requirements of the Contract.

When welding is required, steel reinforcing bars shall be supplied that are suitable for welding. Steel which is to be welded shall have a maximum carbon equivalent of 0.65 percent. The carbon equivalent shall be determined by the following formula:

CE = % C + % Mn/6 + % Cu/40 + % Ni/20 + % Cr/10 - % Mo/50 - % V/10

In addition, carbon shall not exceed 0.45 percent nor manganese 1.30 percent.

Before any welding begins, the Contractor shall submit to the Engineer’s for review, a written welding procedure for each type of welded splice to be used, including the procedure specifications and joint details.The procedure specifications shall specify:

- material specification;

- manual or machine;

- position of weld;

- filler metal specification and classification;

- shielding gas;

- single or multiple pass;

- single or multiple arc;

- either shielded metal arc, flux cored arc, or gas metal arc welding process;

- preheat and interpass temperature;

- welding current;

- polarity; and

- root treatment.

The welding procedure shall specify:

- welding sequence,

- pass number,

- electrode size,

- welding current amperes, and

- voltage for each joint detail.

All the aforementioned information shall be contained on a form that specifies the procedure number, revision number, and the Contractor. The form shall be signed and datedby the Contractor.

Electrodes for manual shielded metal arc welding (SMAW) of Grade 60 steel reinforcing bars shall conform to the requirements of AWS A5.5 of the low hydrogen E90 series.

Solid and composite electrodes for gas metal arc welding (GMAW) and flux-cored arc welding (FCAW) of Grade 60 steel reinforcing bar shall conform to the requirements of AWS A5.28, ER90S and AWS A5.29, E90T respectively. The Contractor shall demonstrate that each combination of electrode and shielding proposed for use produces the following mechanical properties:

FCAW Grade E90T
Tensile Strength	90,000 psi
Yield Strength	78,000 psi
Elongation in 2 inches	17%

Compliance may be verified from manufacturer’s certified test reports, or from actual testing of weld specimens.

All welding shall be protected from air currents, drafts, and precipitation to prevent loss of heat or loss of arc shielding. Short circuiting transfer with gas metal arc welding will not be allowed. Slugging of welds will not be allowed. No field welding of reinforcing bars will be permitted when the ambient temperature is below 32°F.

The minimum preheat and interpass temperature for welding Grade 60 reinforcing bars shall be 400°F. Preheating shall be applied to the reinforcing bars and other splice members within 6 inches of the weld, unless limited by the available lengths of the bars or splice member.

Generally, postheating of welded splices is only required for direct butt welded splices of Grade 60 bars size No. 9 or larger. Postheatingshall be done immediately after welding before the splice has cooled to 700°F. Postheating shall not be less than 800°F nor more than 1,000°F and held at this temperature for not less than 10 minutes before allowing the splice to cool naturally to ambient temperature.

Weld joint and welder qualifications shall be made by the following procedures. The joint qualification and welder qualification shall be according to the following tests.

In the presenceof the Engineer’s Materials and Fabrication Inspector, the welder shall weld three test joints of the largest size reinforcing bar to be weld spliced. Two of the test welds shall be test loaded to no less than 125 percent of the minimum specified yield strength of the bar. The remaining test weld shall be mechanically cut perpendicular to the direction of welding and macroetched. Indirect butt splices shall be cut mechanically at two locations to provide a transverse cross section of each of the bars spliced in the test assembly. The sections shall show the full cross-section of the weldment, the root of the weld, and any reinforcement. The etched cross-section shall have complete penetration and complete fusion with the base metal and between successive passes in the weld. Groove welds of direct butt splices and flare-groove welds shall not have reinforcement exceeding 1/8-inch in height measured from the main body of the bar and shall have a gradual transition to the base metal surface. No cracks will be allowed in either the weld metal or heat-affected zone. All craters shall be filled to the full cross-section of the weld. Weld metal shall be free from overlap. Undercutting deeper than 1/32-inch will not be allowed except at points where welds intersect the raised pattern of deformations where undercutting less than 1/16-inch deep will be acceptable. The sum of diameters of piping porosity in groove welds shall not exceed 1/8-inch in any linear inch of weld or exceed 9/16 inch in any 6 inch length of weld. The Contractor shall first obtain approval of the Engineer for proposed corrections to welds with shielded metal arc, gas metal arc, or flux-cored arc welding processes.

A welder qualified in the vertical position shall then be qualified for the horizontal and flat positions. A welder qualified for the horizontal position shall then be qualified for the flat position but not the vertical position. A welder qualified in the flat position shall be qualified for the flat position only.

Welders qualified for direct butt splice groove welds are qualified for indirect butt splice groove welds and fillet welds. A welder qualified for indirect butt splice grooved welds is not qualified for direct butt splice welds. The welder qualifications shall remain in effect indefinitely unless:

1 the welder is not engaged in a given process of welding for which he/she is qualified for a period

exceeding six months, or

2 there is some specific reason to question a welder’s ability.

Weld joint geometry shall be as shown on the Drawings and in compliance with the Specifications.Welding machines shall be DC current, be reverse polarity, andbe capable of placing welds as specified.

The Contractor is responsible for using a welding sequence that limits the alignment distortion of the bars due to the effects of welding. The maximum out-of-line permitted will be 1/4-inch from a 3.5-foot straight edge centered on the weld and in line with the bar.

The following procedure for welding steel reinforcing bars is recommended:

Sheared bar ends shall be burned or sawed off a minimum of 1/2-inch to completely remove the ruptured portion of the steel shear area prior to welding butt splices. Surfaces to be welded shall be smooth, uniform, and free from fins, tears, cracks, and other defects. Surfaces to be welded and surfaces adjacent to a weld shall also be free from loose or thick scale, slag, rust, moisture, grease, paint, epoxy covering, or other foreign materials. All tack welds shall be within the area of the final weld. No other tack weld will be permitted. Double bevel groove welds require chipping, grinding, or gouging to sound metal at the root of the weld before welding the other side. Progression of vertical welding shall be upward. The ground wire from the welding machine shall be clamped to the bar being welded.

Should the Contractor elect to use a procedure which differs in any way from the procedure recommended above, the Contractor shall submit the differing procedure with reasons for the changes to the Engineer for review. Engineer reviewed weld procedures shall be strictly followed.

The Contractor shall form mechanical splices with an Engineer-reviewedsystem using sleeve filler metal, threaded coupling, or another method that complies with this Section.

The Contractor shall adjust, relocate, or add stirrups, ties, and bars as needed to maintain required clearances after the splices are in place.

The Contractor shall provide the Engineer with the following information for each shipment of splice material before performing splicing:

All splices shall meet these criteria:

When a metallic, sleeve-filler splice is used (or any other system requiring special equipment), both the system and the operator shall qualify in the following way under the supervision of the Engineer. The operator shall prepare 6 test splices (3 vertical, 3 horizontal) using bars having the same AASHTO Designation and size (maximum) as those to be used in the work. Each test sample shall be 42 inches long and shall consistof two 21-inch bars joined end-to-end by the splice. The bar alignment shall not deviate more than 1/8 inch from a straight line over the whole length of the sample. All 6 samples must meet both the tensile strength and the slip criteria specified in this Section.

The Contractor shall provide labor, materials, and Equipment for making these test samples at noadditional cost to the Owner. The Owner will test the samples at no cost to the Contractor.

As the work progresses, the Engineer may require the Contractor to provide a sample splice (thermal or mechanicalor both) to be used in a job control test. The operator shall create this sample on the job site with the Engineer present using bars of the same size as those being spliced in the work. The sample shall comply with all requirements of these Specifications, and is in addition to all other sample splices required for qualification. The Engineer will require no more than two acceptable samples that conform to the specified splicing procedures on any Project with fewer than 200 splices and no more than one acceptable sample per 100 splices on any Project with more than 200 splices.

This work is furnishing, fabricating, coating, and placing epoxy-coated steel reinforcing bars as shown in the Contract. Coating material shall be applied electrostatically, by spraying, or by the fluidized-bed method.

All epoxy-coated bars shall comply with the requirements of Section 9-07. Fabrication may occur before or after coating.

The Contractor shall protect epoxy-coated bars from damage using padded or nonmetallic slings and straps free of dirt or grit. The Contractor shall lift bundled bars with a strong-back, multiple supports, or a platform bridge to prevent abrasion from bending or sagging. Bundled bars shall not be dropped or dragged. Bars shall rest on wooden or padded cribbing during shop or field storage. The Contractor may substitute other methods for protecting the bars if the Engineer approves. Coated bars that havesignificant damage (significant damage defined in this Specification Section) will be rejected.

Metal chairs and supports shall be coated with epoxy or other inert coating approved in writing bythe Engineer. The Contractor may use other support devices with prior written approval of the Engineer. Plastic coated tie wires, approved in writingby the Engineer, shall be used to protect the coated bars from being damaged during placement.

The bars shall be placed as indicated onthe Drawings. The bars shall be secured firmly in place during placing and setting of the concrete. All epoxy-coated bars in the top mat of the roadway slab, and epoxy-coated bars with spacing intervals of 1 foot or greater, shall be tied at all intersections. Epoxy-coated bars not in the top mat of the roadway slab, and with bar spacing intervals of less than 1 foot,shall be tied at alternate intersections.

The Contractor shall protect the epoxy-coating from damage that might result from other construction work in the interval between installing coated bars and concreting the deck.

The Engineer will inspect the coated bars after they are placed and again before the deck concrete is placed. The Contractor shall patch any areas that show significant damagedefined as follows.

Significant damage means the Engineer has determinedany opening in the coating that exposes the steel in an area that exceeds:

The Contractor shall patch significantly damaged areas with a patching material obtained from the epoxy resin manufacturer which has been submitted to and reviewed by the Engineer.This patching material shall be compatible with the coating and inert in concrete. Areas to be patched shall be clean and free of surface contaminants. Patching shall be done before oxidation occurs and according to the resin manufacturer’s instructions.

The manufacturing plant of prestressed concrete girders shall be certified by the Precast/Prestressed Concrete Institute’s Plant Certification Program for the type of prestress member to be produced and shall be approved by WSDOT as a Certified Prestress Concrete Fabricator prior to the start of production as part of WSDOT's annual plant review and approval process. Proof of plant certification by P/PCI and by WSDOT shall be submitted along with the Shop Drawings by the Contractor to the Engineer.

The Contractor shall providethe Engineer at least 3 Working Days advance noticeof the girderproduction schedule. The Contractor shall give the Engineersafe and unencumberedaccess to the work. If non-Specification work or unacceptable quality control practicesare observed, the Engineerwill advise the plant manager with Written Notice.Theproposed corrective action shall beacceptable to the Engineer. Failure to provide acceptable corrective action will be cause for rejection ofthe girder(s).

All reinforcement, from manufacture to encasement in concrete, used in girders shall be protected against contamination such as dirt, oil, grease, damage, rust, all corrosives, and any other material deleterious for its intended use. The proposed protection method requires the Engineer’s advance written approval. Reinforcement will be rejected if found contaminated.

The various types of girders are:

Prestressed Concrete Girder - Refers to prestressed concrete girders including Series W42G, W50G, W58G, and W74G girders, bulb tee girders, and deck bulb tee girders.

Bulb Tee Girder - Refers to a bulb tee girder or a deck bulb tee girder.

Deck Bulb Tee Girder - Refers to a bulb tee girder with a top flange designed to support Trafficloads (i.e., without a cast-in-place deck). This type of bulb tee girder is mechanically connected to adjacent girders at the Project Site.