00540Structural Concrete

00540.00 Scope - This Work consists of furnishing, pla cing, and finishing portland cement concrete,

throughout this Specification referred to as structural concrete or concrete, for Bridge s and other Structure s according to the Specifications and in close conformity to the lines, grades and dimensions shown or established.

00540.01 Abbreviations and Definitions :

Falsework - Structural system to support the vertical and horizontal loads from forms, reinforcing steel, plastic concrete, structural steel, loads from placement operations and other related loads . Forms - Structural system to contain the horizontal pressures exerted by plastic concrete. HPC - High Performance Concrete - See 02001.02 for definition. Post-Tensioned - Tensioning of prestressing steel after concrete has reached specified strength. Surrounding Temperature - The air temperature measured in the shade. When placement and curing of concrete is enclosed, it is the lowest temperature within the enclosure. Tolerance: • The permitted variation from a given dimension or quantity, or • The range of variation permitted in maintaining a specified dimension, or • A permitted variation from location or alignment.

00540.02 Deck Pre-Placement Conferences:

(a) Supervisory Personnel - Hold a pre-placement conference with all supervisory personnel who are to be involved in the concrete Work at a mutually agreed time approximately 3 weeks in advance of placing concrete for bridge decks. Ensure the Engineer, concrete Supplier , and any other Subcontractor is represented. Present and discuss all phases of the concrete deck placement Work . (b) Placement Crew - Hold a second pre- placement conference with the Engineer and the entire concrete placement crew at the Project Site 1/2 hour before the first placement begins to discuss placem ent duties and procedures.

00540.03 Required Submittals for Deck Sidewalk and Curb Ramps - Material ordered or Work

done before the Engineer reviews and returns the documents shall be at the Contractor's risk. Submit the following: (a) ADA Certification for Contractors - For all supervisory personnel who directly supervise the curb ramp Work, submit the names, telephone numbers, and copies of the ODOT ADA Certification for Contractors at least 10 Calendar Days before the preplacement conference. (b) Working Drawings - Submit Working Drawings for curb ramp Work at least 10 Calendar Days before the construction of the curb ramp Work according to 00759.03(c). 00540.10 476 (c) Corrective Action Plan - Unless otherwise approved, notify the Engineer before performing corrective action on curb ramps. Include temporary pedestrian access routes necessary to complete the corrective action Work. At least 21 Calendar Days before concrete pedestrian structure Work is scheduled to begin, submit a corrective action plan. Include the plan items according to 00759.03(d). The Engineer will review the corrective action plan(s) and provide a response to the Contractor within 5 Days after receiving the plan. Do not begin concrete pedestrian structure Work until the cor rective action plan is approved by the Engineer. Materials

00540.10 Materials - Provide sampling, testing, and quality control according to Section 00165.

Furnish Material s meeting the following requirements: Concrete ..................................................................................................... 02001 Concrete and Crack Sealers ...................................................................... 02060 Concrete Coating ....................................................................................... 02210 Curing Materials ......................................................................................... 02050 Concrete Surface Retarder ........................................................................ 02055 Epoxy and Non-Epoxy Bonding Agents ..................................................... 02070 Epoxy and Non-Epoxy Grouts .................................................................... 02080 Epoxy Cement ............................................................................................ 02060 Portland Cement Concrete Repair Material ................................................ 02015 Hot Applied Joint Sealant ...................................................................... 02440. 30 Preformed Expansion Joint Filler .......................................................... 02440.10

00540.11 Classes of Concrete - Furnish concrete meeting the requirements of Section 02001 and

the requirements of Table 02001-1 for the classes of concrete to be used in various Structure s and concrete paving mixtures. The Plans or Special Provisions will show the class of concrete required for the component parts of the Structure . Use the specified class of concrete, or a higher class. Where the class is not specified, use Class 3300.

00540.14 Concrete Mix Tolerances and Lim its - Furnish a workable concrete mixture, uniform in

composition and consistency and meeting the properties and limits requirements of 02001.20.

00540.15 Form Materials - Furnish wood, minimum nominal 5/8 inch thick APA exterior grade

plywood, minimum nominal 5/8 inch thick APA plyform, metal, or other suitable form material. For round concrete columns, provide either metal or other approved f orm material that produces a smooth and true surface free from fins, joints and other irregularities. Use APA plyform for all decks and slabs.

00540.16 Quality Control - Provide quality control according to Section 00165 and the following:

• For all structural concrete, provide personnel according to 00540.30 to sample and test the mix for temperature, air content, slump, water -cementitious ratio, density and yield, from the first load of each placement, whenever there is a visible change in the slump of the concrete, and when a set of cylinders is obtained. • If the results of any test are outside of the Specification limits, stop placement of the load. Correct the load or, i f the load cannot be corrected, do not incorporate it into the Work . Test subsequent loads before any further concrete placement. Correct subsequent loads if any of the tests are still outside the Specification limits. Return to the specified test freque ncy when the test results from two consecutive loads are shown to meet the Specification limits.

00540.17 Acceptance of Concrete - Acceptance of concrete will be according to Section 00165 and

the following: 00540.22 (a) Aggregate - Acceptance of Aggregate will be according to 02690.12. (b) Plastic Concrete - Acceptance of plastic concrete will be based on tests performed by the Contractor's QCT, according to the Tolerances and limits of 02001.20. (c) Hardened Concrete - Cast and cure test specimens according to AASHTO T 23 in 6 inch x 12 inch or 4 inch x 8 inch, single -use plastic molds and test at 28 Days according to AASHTO T 22. (1) General - For all classes of concrete, acceptance of hardened concrete wi ll be based on an analysis of compressive strength tests of cylinders cast by the QCT. Test cylinders at an ODOT certified laboratory. (2) Acceptance - Hardened concrete with an ASTV meeting or exceeding the specified design strength, ƒ'c will be accepted for strength. If the ASTV is less than ƒ'c but at least 85 percent of ƒ'c, the Engineer may review the results to determine if the concrete represented by the cylinders is suitable for the intended purpose. Remove concrete that has an ASTV less than 85 percent of ƒ'c unless otherwise authorized, in writing, by the Engineer. If the concrete is removed, the cost of removal, replacement and all related Work is the Contractor's responsibility. If the Engineer determines that the concrete is suitable for the intended purpose, the concrete may be allowed to remain in place, subject to a price adjustment according to 00150.25. If an ASTV falls below ƒ'c, the Contractor may submit a written plan outlining a proposed alternate method of evaluating compressive strength. Submit the plan for review by the Engineer within 3 Days of the test. Provide evidence that a reasonable ƒ'cr (over-design) was maintained and that there is credible evidence (besides low strength) which warrants consideration of this option. The Engineer may allow an alternate method of acceptance if the compressive strength test results are determined to be suspect from definable external factors. Equipment

00540.22 Concrete Conveying Equipment - Use clean, non-aluminum conveying Equipment

capable of supplying concrete to the point of placement without segregation. (a) Concrete Pumping Equipment - Provide a discharge line for the pump made of steel or rubber pipe and having the following minimum size: Nominal Maximum Size Minimum Pipe Size, of Concrete Aggregate Inside Diameter 1 inch 4 inches 1 1/2 inches 5 inches (b) Chu tes - Use steel or steel -lined chutes. Where steep slopes are required, equip the chutes with baffles or provide short lengths that reverse the direction of movement. (c) Pipes or Trunks - Other than tremie seal pipe, provide rubber or steel pipes, and plastic trunks. (d) Tremie Seal Pipe - Provide a tremie seal pipe that: • Is rigid pipe with minimum diameter of 10 inches and sufficient length to reach from the bottom of the excavation to above the waterline, with an attached receptacle or hopper for receiving concrete. • If jointed, is the flange -and-gasket type and waterproof. 00540.23 478 • Has means to close the discharge end. • Is supported to permit free movement of the discharge end throughout the seal. • Is equipped with a device to permit rapid lowering when necessary to retard or stop the flow of concrete.

00540.23 Vibrators - Provide vibrators that:

• Are an internal type unless other methods are approved by the Engineer. • Are capable of transmitting vibration to the concrete at frequencies of not less than 4,500 impulses per minute. • Are in working condition to meet manufacturer's rating. • Are fitted with a manufactured rubber sleeve to prevent damage to epoxy coated reinforcement.

00540.24 Deck Finishing Machine - Provide a deck finishing machine that is:

• Capable of finishing the entire Roadway surface or the specified stage construction width. • Self-propelled with positive control in both forward and reverse directions. • Capable of raising rolls or screed to clear the screeded surface with positive control to the specified grade. • Equipped with augers. • Equipped with rollers or vibrating screeds. (a) Deck Finishing Machine Support System - Furnish calculations and detailed drawings of the proposed deck finishing machine support system according to 00540.41. (b) Other Deck Finishing Equipment - In narrow Bridge widenings where a deck finishing machine is not practicab le, a mechanical vibrating screed may be used.

00540.25 Straightedge - Furnish a 12 foot metal straightedge for checking bridge de ck roadway and

sidewalk surface T olerances.

00540.26 Concrete Saws - Provide power -driven concrete saws for sawing joints and as required

for surface texture.

00540.28 Power Washers - Provide power washers that produce a minimum 2,500 psi pressure at

the nozzle, with a fan pattern, and a minimum 4.5 gallons per minute capacity. For bridge decks, provide at least one power washer for each side of the deck section to be placed. When using power washers to produce a fog spray for curing, match the flow rates and pressures of the power washers with the fogging nozzles to produce an average droplet size of 3 mils, according to the nozzle manufacturer's recommendation.

00540.29 Work Bri dges - Provide at least two transverse work Bridge s when placing concrete on a

bridge deck. Use the transverse work Bridge s to facilitate placement of the cure. Labor

00540.30 Personnel Qualifications - In addition to the certified technicians requir ed in 02001.50

provide and designate an individual to be present at the placement site at all times during concrete placements for projects with more than 100 cubic yards of structural concrete and for all H igh Performance Concrete, and who is authorized and responsible for acceptance and rejection of Materials. 00540.40 479 Provide onsite supervisory personnel that are ODOT ADA Certified during construction of the curb ramps. Construction

00540.40 Tolerances - The following T olerances apply to cast -in-place Structure s:

(a) Foundation Footings: (1) Lateral Alignment: • Actual (as cast) location of the center of gravity: 0.02 times width of footing in the direction of misplacement, but not more than 2 inches • Supporting masonry: 1/2 inch (2) Level or Vertical Alignment: • Top of footing supporting masonry: 1/2 inch • Top of other footings: minus 2 inches to plus 1/2 inch (3) Cross -Sectional Dimensions:

00540.41 Design of Falsework :

(a) Submittal of Working Drawings and Calculations - Submit stamped F alsework Plans and design calculations according to 00150.35, except as modified below. Ensure the Falsework designer prepares a Falsework Design Summary and completes a Falsework Design Checklist to accompany the Plans and calculations. Include in the summary a list of each F alsework member with its: • Assumed dead and live loads • Allowable and design stresses • Allowable and calculated deflections • Design references and derivations for design formulas • Documentation for computer -generated calculations The Falsework Design Checklist is included in the Special Provisions. Submit five sets (nine sets if Railroad approval is required) of the Plans and three copies (five copies if Railroad approval is required) of the calculations, summary, and checklist. 00540.41 481 Design Falsework acc ording to the current edition of AASHTO Guide Design Specifications for Bridge Temporary Works except where in conflict with the Specifications. (b) General Design Loads - Design and construct Falsework to support the total applied loads and provide enough redundancy in the design to prevent a failure of the entire system. Ensure design loads used are the maximum loadings. Ensure deflections used on manufactured devices and assemblies do not exceed the manufacturer's recommendations. Furnis h catalog data that lists the manufacturer's recommendations. (c) Falsework Foundation: (1) On Soils - Consider anticipated construction and Soil conditions in determining the Soil's support capacity, including draining water away from the supports. F or Falsework supported on Soils , show the following in the calculations: • Assumptions and methods used to determine the Soil's capacity to support the footing loads. • Anticipated Falsework footing settlement based on the allowable Soil bearing values. (2) On Piles - For Falsework supported on piles, show on the Working Drawings the pile type, size and spacing. Accompany these drawings with calculations which show the assumptions and methods used to design the piles and the bearing values to which the piles need to be driven to support the calculated loads. (d) Requirements at Highway and Railroad Traffic Openings - For Falsework adjacent to or spanning a Highway or Railroad traffic opening, do the following: • Design the posts using a minimum elastic section modulus, about each axis, of: • 12.2 cubic inches for structural steel • 244 cubic inches for timber • Increase the vertical post load 150 percent. If the load on the F alsework will be increased by load transfer due to prestressing, increase the vertical post load by the additional load due to prestressing or by 150 percent, whic hever is greater. • Provide mechanical connections for posts to supporting footing with capacity to resist a minimum lateral force of 2,000 pounds applied in any direction at the base of the post. • Provide mechanical connections between top of posts and the c ap or stringer capable of resisting a lateral force of 1,000 pounds from any direction. • Tie down all beams or stringers spanning traffic so that each will resist a 500 pound force from any direction. • Use 5/8 inch diameter or larger bolts at connections for timber bracing. • Show temporary erection/removal bracing on the Falsework Plans . (e) Additional Requirements at Railroad Traffic Openings - For Falsework bents within 20 feet of the track centerline: • Design bracing so that the bent will resist the required horizontal load or 5000 pounds, whichever is greater. • Provide solid sheathing of 5/8 inch thick plywood between 3 feet and 16 feet above the top of the rail, properly blocked at the edges. • On Falsework Plans , show: 00540.42 482 • Collision posts if they are requ ired • Soffit and deck overhang forming details (f) Concrete Forms on Steel Structures - Provide sufficient temporary bracing or temporary struts and ties to minimize lateral deflection and rotation of the exterior steel girder. Calculate exterior girder rotation according to the Oregon Bridge Design Manual section 1. 16.3. Limit deck deflection at the edge of deck due to girder rotation to no more than 1/4 inch. Support compression member or bottom connection of cantilever formwork support brackets either within 6 inches maximum vertically of the bottom flange or within 6 inches maximum horizontally of a vertical web stiffener. If partial depth cantilever formwork support brackets are permitted, submit Working Drawings showing the additional formwork str uts and ties used to brace the steel girder against web distortion.

00540.42 Falsework Construction - Construct Falsework according to the current edition of

AASHTO Construction Handbook for Bridge Temporary Works , exc ept where in conflict with the Specifications. Assure that F alsework is constructed according to the F alsework design and on Soils equal to or exceeding design assumptions. Within 2 Days of notice of the falsework design engineer's pending inspection, the Engineer will provide a list of construction concerns. Do not place concrete until the falsework design engineer of record, accompanied by the Engineer, field inspects that portion of the F alsework proposed for use. Do not place concrete until all const ruction concerns have been addressed, the falsework design engineer furnishes the Engineer a written statement that the Falsework conforms to the design and will serve the intended use, and the Engineer agrees in writing that the F alsework will serve the intended use. Set Falsework to give the finished Structure the Camber shown or specified. Install telltales on F alsework at locations as directed and use jacks, hardwood wedges or other methods approved, to take up settlement in the formwork. When used, provide sand jacks consisting of a metal piston and metal frame filled with compacted, clean, dry S and. Ensure the annular space between the top bearing plate or piston and the frame does not exceed 1/4 inch. Use temporary barriers according t o 00226 .11(a) to protect Falsework from damage from adjacent traffic. Make provisions to prevent damage by debris in streams. Upon completion of the Structure , remove all Falsework to at least 24 inches below ground line or streambed. Limit the height of timber blocking and wedging to 24 inches, or to less than 1 1/2 times the least horizontal dimension of the blocking or wedges, whichever is smaller. Limit post, shim pack and wedging assemblies supporting beams to six faying (interface or contact) surf aces. Ensure adjacent beam support assemblies do not have a difference of more than two faying surfaces. Ensure timber blocks loaded perpendicular to the grain are free of splits. For Post-Tensioned Structure s, do not remove F alsework until post -tension ing is complete.

00540.43 Joints - Construct joints in concrete Bridge s according to details shown or directed.

(a) Construction Joints - Make construction j oints between concrete placements only where shown or specified unless otherwise approved. 00540.43 483 Do not form construction joints in concrete exposed to salt water between levels of extreme low and high water. Where concrete may be exposed to the action of alka line water or Soil, place concrete continuous until completion of the section, or until the concrete is at least 18 inches above the ground or high water level. Unless otherwise shown, provide construction joints with a roughened surface. Do not smooth o r trowel Aggregate into the cement paste. Provide a minimum deviation from a plane surface or 1/4 inch and a maximum deviation from a plane surface equal to the maximum size of Aggregate in the specified class of concrete. Apply a concrete surface retarder according to the manufacturer's recommendations. Remove surface mortar within the time period recommended by the manufacturer and clean the joint surface and reinforcing steel by removing loosened particles of Aggregate, damaged concrete, unconsolidated concrete and surface laitance with a high pressure washer conforming to 00540.28 to the extent that clean Aggregate (free of surface mortar) is exposed on 50 percent of the surface. Clean the joint surface again immediately prior to the concrete placement to remove any subsequent deposits of dirt, debris or other foreign materials. Saturate the joint surface with potable water immediately before resuming concrete placement. Remove standing water in depressions or hollows of the joint surface. Sawcut the top 1 inch of the deck joints with a straight vertical cut before subsequent concrete placement and before saturating the surface with water. Where joints are straight and without spalls, the Engineer may waive this sawcut requirement. Hand rub or brush fresh concrete paste onto the existing surface of vertical deck joints down to the top mat of reinforcing steel at the beginning of subsequent concrete placement. Stay in place joint F orms are not allowed in bridge deck construction joints. (b) Open Joints - Locate open joints as shown. Construct the form so the form support system may be released as soon as the concrete takes its initial set. Do not chip or break the corners of the concrete when removing Forms. Do not extend reinforcing bars across an open joint unless shown. (c) Joints with Fillers - Construct joints with preformed expansion joint fillers or poured fillers as shown and according to the manufacturer's recommendations for the filler used. Provide a 3/4 inch chamfer on each edge of the joint unless otherwise noted. (d) Bridge Deck Expansion Joints - Construct expansion joints for bridge decks as shown and according to Section 00585. (e) Construction Joints Between Existing and New Concrete - Construct construction joints between existing and new concrete as shown or directed. If not shown, roughen surfaces on existing concrete and prepare the surfaces for joints located in structural members as specified. Sand-blast or wa ter-blast existing concrete surfaces where shown or directed. Roughen surface to a uniformly distributed 1/4 inch minimum amplitude surface profile. If approved, bush hammers or scabbler may be used for roughening existing concrete surfaces. Use pneumat ic hammers, chipping guns, manual picks and chisels for area with limited access. Do not use pneumatic hammers heavier than a nominal 15 pound class. Remove loosened particles of Aggregate and damaged concrete with a high -pressure washer conforming to 00540.28. Visually verify the surface profile of all prepared surfaces according to International Concrete Repair Institute (ICRI) Guideline 310.2R -2013 Selecting and Specifying Concrete Surface Preparation for Sealers, Coatings, Polymer Overlays, and Conc rete Repair - surface profile CSP 7. 00540.44 Remove all loose particles, dust, dirt, laitance, oil, or film of any sort. Abrasive -blast exposed existing reinforcing bars according to SSPC Standard SP6 Commercial Blast Cleaning or equivalent procedure. Saturate the existing concrete surface with potable water for 24 hours minimum before placing concrete against the existing surface. Remove standing water in the depressions or hollows of the roughened surface. Sawcut the top 1 inch of the construction joint surf aces to form a straight line joint before saturating the surface with water and before placing concrete. Where joints are straight and without spalls, the Engineer may waive the sawcut requirement. Hand rub or brush fresh concrete paste onto the existing concrete surface down to the top mat of reinforcing steel at the beginning of subsequent concrete placement.

00540.44 Foundations - Place concrete foundations for Structure s on suitable Soil or Rock bearing

surfaces, concrete seals or piles as shown. Excavate and backfill according to Section 00510.

00540.45 Construction of Forms - Construct Forms that:

• Conform to ACI 347 and ACI SP-4. Are mortar-tight and sufficiently rigid to conform to and maintain the specified dimensions and Tolerances. Provide a 3/4 inch chamfer on all exposed concrete edges unless otherwise noted. Provide a smooth concrete surface unless otherwise specified. Are c onstructed so portions may be removed without disturbing F orms that are to remain. Are treated with a release agent that is not detrimental to the concrete. Are cleaned of dirt, sawdust, excess water and other foreign material before placing concrete in the Forms. • Are saturated with water immediately before placing concrete and kept damp during placement. • Are retightened before depositing new concrete on or against concrete which has hardened. On Structure s located within 25 aerial miles of the Pacific Oce an, remove metal ties and anchorages to a depth of 2 inches from accessible surfaces. Remove fiberglass form ties and anchorages to a depth of 1 inch from accessible surfaces. On Structure s located more than 25 aerial miles from the Pacific Ocean, constr uct ties or anchorages within the Forms so they can be removed to a depth of at least 1 inch from accessible surfaces. Install embedded conduit 2 inches clear of the nearest face of concrete. Secure in place expanded polystyrene F orms and spacers between adjacent concrete placements to prevent floating or displacement during concrete placement. Carefully cut joints in expanded polystyrene and fill with a suitable filler or mastic to prevent intrusion of concrete mortar. After the concrete has hardened, completely remove expanded polystyrene unless otherwise stated. Permanent stay -in-place bridge deck F orms are not allowed unless shown otherwise. Use removable concrete Forms on all steel Structures. Do not weld any part of the form to any steel girder. (a) Footings - When footings are not founded in firm Rock , concrete may be placed without Forms if the excavation does not exceed the T olerances of 00540.40(a)(3)(b). 00540.48 Do not form portions of footings founded in firm Rock . Place concrete against undisturbed Rock , filling the overbreak to the top of Rock or top of footing. (b) Accessible Box Girder Cells - Falsework and deck Forms for accessible box girder cells may be supported by girder stems or bottom slab provided the bottom slab is fully supported and designed to take additional loading from deck Forms and Falsework, deck concrete, and concrete placement forces. (c) Inaccessible Box Girder Cells - Falsework and deck Forms for inaccessible box girder cells may be left in place provided: • Falsework and deck Forms left in place are not supported off the bottom slab. Falsework and deck Forms supported by girder stems are allowed. • 1/2 inch preformed expansion joint filler are placed between the end of deck Forms and transverse beams and at 25 foot spacing in the deck F orms. • Box girder cells are cleared of materials and Forms except as necessary to support the deck slab before the deck forming is compl ete. (d) Form Maintenance - Set Forms and maintain them true to designated line and grade until the concrete hardens. When F orms appear to be unsatisfactory, either before or during the placing of concrete, the Engineer may order the Work stopped until the defects have been corrected. Leave Forms in place for periods specified in 00540.52.

00540.47 Delivering Concrete - Schedule delivery of concrete to ensure continuous delivery during

placement. For all placements except seal and deck placements, ensure the interval between the end of one load and the start of the next load does not exceed 20 minutes. See 00540.48 for seal and deck placements. If the requirements of the previous paragraph are not met, the Engineer will determine whether the concre te has taken its initial set and may order a bulkhead installed or removal of concrete in the affected placement.

00540.48 Handling and Placing Concrete :

(a) General - Do not place concrete under water or in flowing water unless specifically authorized. Place concrete: • In the sequence shown or as approved. • In its final position in the F orms within 1 1/2 hours after the addition of the cement to the Aggregate. A retarder may be used or required. Use a retarder from the QPL and furnish at no additional cost to the Agency. • As close as possible to its final position and consolidated to: • Avoid segregation of the Materials and displacement of the reinforcement • Produce a dense, homogeneous concrete, free of voids and Rock pockets • Through pumps, chutes or trunks conforming to 00540.22, when placement requires dropping concrete more than 5 feet. Place the bottom of pump hose, chutes, pipes or trunks as close to final placement position as practica ble. • In layers not more than 18 inches thick, except for seal concrete placement, and unless shown otherwise. Place and consolidate each layer before the preceding layer has taken initial set to avoid surfaces of separati on between the layers. 00540.48 486 Do not place concrete prior to complete approval of: • The excavation and the bearing material in a foundation • Installed piling • The Falsework and F orms • Placed reinforcing steel After initial set of the concrete, do not disturb the F orms or place loads on the ends of reinforcing bars projecting from the concrete placement until allowed by 00540.52. (b) Pumping Concrete - Pump concrete with pumping Equipment conforming to 00540.22. Pump a cement -water slurry through the lines before starting the mix through the pump. Operate the pump in a manner that produces a continuous stream of concrete without air pockets or segregation. When a placement nears completion, if concrete remaining in the pipeline is to be used, remove it in a manner that will not cause contamination of the concrete already in place. There will be no extra payment for additional cement or additives required to ensure a mix is pumpable. (c) Vibrating Concrete - Except for seal con crete, thoroughly consolidate fresh concrete according to the following: • Vibrate concrete internally using mechanical vibrating Equipment . • Provide an extra vibrator for emergency use. • Re-vibration of concrete may be required as directed. Apply vibration at the point of freshly deposited concrete. Apply vertically at points uniformly spaced not farther apart than 1 1/2 the radius over which the vibration is visibly effective. Penetrate into previously placed plastic layers. Do not use vibrators to make concrete flow or to move concrete from one point to another in the Forms. Do not apply directly on or through the reinforcement to sections or layers of concrete which have hardened to the degree that the concrete ceases to be plastic under vibration. Supplement vibration by spading as necessary to ensure smooth surfaces and dense concrete along form surfaces and in corners or other locations impossible to reach with vibrators. Continue vibration until the concrete is thoroughly consolidated. Discontinue vibration if segregation occurs or localized areas of grout form. (d) Concrete Exposed to Salt Water, Alkaline Water, or Soil - For concrete exposed to salt water, see 00540.43(a) for location of construction joints, and 00540.53 for surface finish requirements. Do not allow alkaline water or Soil to contact the concrete during placement or for a period of at least 72 hours after placement. See 00540.43(a) for location of construction joints. (e) Seal Concrete - Deposit seal concrete in still water near its final position, by means of a tremie seal pipe meeting the requirements of 00540.22(d) or a concrete pump with a rigidly held discharge line to prevent unwanted vertical movement. Place seal conc rete continuously from start to finish, at a rate of at least 50 cubic yards per hour, keeping the surface of the concrete nearly horizontal at all times. Place each increase in height before the preceding concrete has taken its initial set. 00540.48 487 Do not use v ibrators. At the start of the Work and on any withdrawal of the pipe, close the discharge end to prevent water entering the pipe. During the progress of the Work , keep the pipe full of concrete to the bottom of the hopper. When concrete is dumped into t he hopper, start the flow of concrete by slightly raising the discharge end, always keeping it in the deposited concrete. Control the elevation of water inside the cofferdam to prevent any flow through the seal. Dewatering may proceed when the concrete s eal has achieved a compressive strength of 2,200 psi. Remove high spots, laitance and other unsatisfactory material from the exposed surface. (f) Walls, Abutments, Bents, Piers, Columns, Beams, Girders, and Slabs - Place concrete following the sequences shown and the delay period specified in 00540.52. Delay placement for the Superstructure until the column Forms have been stripped sufficiently to determine the character of the column concrete. Ensure Superstructure loads are not carried by the bents or piers until the concrete has been in place and has attained the strength specified in 00540.52. Stop placement for the bottom slab of box girder Structure s at the bottom of beam stems or bottom of stem fillets. Before placing concrete in the stems, wai t for a period not less than that specified in 00540.52. Stop placement for T -beams and box girder stems at the bottom of the deck fillet. Before placing deck concrete, wait for a period not less than that specified in 00540.52. (g) Bridge Decks - Use deck finishing machines conforming to 00540.24 and set to run parallel to the skew of the bent lines. Place screed rails outside the finishing area. Extend screed rails beyond both ends of the scheduled placement length for a distance that allows the finishing machine to reach all of the concrete. For Bridge s with continuous spans, ensure reinforcing steel is in place and tied in any adjacent span in the continuous Bridge segment before placing concrete. Before placing concrete, operate the finishing machine the length of the proposed placement, and check th e deck thickness and clearance from the screed to the reinforcing steel in the presence of the Engineer, by an approved method. The permissible variation from the clearance indicated will be plus or minus 1/4 inch. Make necessary corrections before begi nning the placement. Furnish transverse work Bridge s according to 00540.29. Extend the screed rails beyond the start end to allow placement of all transverse work Bridge s on the screed rails before placement of concrete begins. Do not place bridge deck concrete until the Engineer is satisfied that the Contractor: • Meets the requirements of 00540.41, 00540.45 through 00540.49, and 00540.52. • Has the finishing machine and transverse work Bridge s placed and ready on the screed rails. • Is able to deliver concrete for decks so deck placement progresses at a rate of not less than 20 feet per hour. • Proceeds up grade from the lowest deck elevation, unless otherwise shown. • Is able to produce and place concrete at a rate sufficient to complete proposed placement and finishing operations within the specified time. 00540.49 488 • Illuminates the work area during hours of darkness. • Has experienced concrete finishers and necessary finishing tools and Equipment at the Project Site . • Provides wind breaks, fog spray, or other approved methods when the concrete surface is exposed to conditions which may cause premature drying during placement operations. • Has saturated the tops of precast prestressed concrete members and formwork by applying continuous water for a minimum of 2 hours immediately prior to beginning deck placement. If delays occu r lasting longer than 30 minutes, the Engineer may order construction of a bulkhead. If a bulkhead is constructed, do not begin further placement in that span or the adjacent F alsework span, if any, for at least 24 hours. Construct bulkheads only where s hown or when directed by the Engineer.

00540.49 Weather Conditions for Concreting :

(a) All Concrete Placement: (1) Hot Weather - Maintain the concrete temperature during hot weather as specified. When concrete temperatures approach the maximum allowable temperature according to 02001.20(d) , take appropriate action to lower the concrete temperature. Do not place concrete on or i n Forms if surface temperature of Forms or reinforcing steel is 90 °F or above. (2) Cold Weather:

0.15 lb/sq ft/hr rate of

evaporation.) 0 2 5 10 15 20 25 Wind Velocity, mph 40 50 60 70 80 90 100 Concrete Temperature, °F Relative Humidity, % 10 20 30 40 50 60 70 80 90 100 00540.51 491 00540.50 Bridge Deck Roadway and Sidewalk Finish : (a) General - After the bridge deck roadway and sidewalk concrete is placed and consolidated, strike it off to lines, grades and Cross Section s shown. (b) Deck Roadway Finish - After the deck roadway concrete has been screeded with a finishing machine conforming to 00540.24, float, if necessary, to produce a uniform surface, according to 00540.55. If the Work does not conform to the pr escribed limits, stop the operation until revised methods, changes in Equipment , or correction of procedures are approved for trial. Also stop the revised operation if it does not produce a specified surface. (c) Deck Roadway Texturing - After correcting any non -specification surface T olerance according to 00540.55, texture the deck roadway surface with a saw that cuts grooves into the bridge deck as follows: • Cut grooves 1/8 inch wide and 1/8 inch to 3/16 inches deep. • Space grooves randomly from 3/4 inch to 1 1/2 inches apart with a minimum of 12 grooves for every foot of deck surface. Measure groove spacing parallel to the roadway centerline. • Orient the grooves perpendicular to the roadway centerline and full width of the Roadway except leave smooth strips 16 inches wide along each curb face. Do not overlap grooves. • Do not groove within 6 inches of joint blockouts and bridge ends. For skewed Bridge s, additional ungrooved portions at joint blockouts and bridge ends are allowed to accommodate the width of the gang saw. • Continuously remove saw slurry and laitance from the sawing operation while cutting grooves. • Cut grooves after the bridge deck has been checked for non- specification surface Tolerances as req uired by 00540.55 and after the water cure is complete. • Cut grooves no sooner than 14 Days after the deck is cast. Cut grooves before opening the Roadway to traffic. For Structure s constructed in stages, the Roadway may be opened to traffic before cuttin g grooves provided the time period from opening to actual construction of grooves is between June 1 and October 1. (d) Deck Sidewalk and Curb Ramp Finish - Finish concrete surfaces on pedestrian facilities including but not limited to sidewalks, curb ram ps and pedestrian structures that contain a Pedestrian Access Route (as defined in 00759.02) according to 00759.50.

00540.51 Curing Concrete :

(a) General Requirements - Cure cast -in-place concrete surfaces with water , wet burlap, and a layer of 4 mil polyethylene film , except polypropylene fabric may be used in place of wet burlap on horizontal surfaces . Begin curing as soon after placement as possible without damaging the freshly placed concrete. Continue curing for 7 Calendar Day s (14 Calendar Day s for bridge decks) after placement. Keep surfaces not covered by waterproof Forms damp by applying water with a fog nozzle until the surface has set sufficiently to allow sprinkling with water or covering with wet burlap or an approved wet or dry material. Do not interrupt curing for more than 1 hour during the curing period. If the ambient temperature falls below 50 °F, or is forecasted to be below 50 °F, provide a 24-hour continuous recording thermometer and place it directly on the surface of the concrete. Once placed, the thermometer shall remain in place for the duration of the cure period. Use methods 00540.52 492 approved by the Engineer to maintain a con crete temperature of at least 50 °F during the cure period. (b) Curing Concrete Bridge Decks - In addition to requirements of 00540.49, cure cast -in-place concrete bridge deck surfaces by doing the following: • Provid e wind breaks or other approved methods when exposed to conditions which may cause premature drying during placement operations. Premature drying is defined as an evaporation rate equal to or greater than 0.10 pounds per square foot per hour, as determined from Figure 00540- 1, or as the loss of surface sheen when the evaporation rate at the surface exceeds the bleed rate. • Provide high pressure washers, according to 00540.28, fitted with fog nozzles during all deck placements to prevent and control prematur e drying. Apply fog spray upwind of the concrete placement during finishing. The purpose of fogging is to maintain a layer of high humidity above the concrete surface in order to minimize water loss in the mix after placement and before application of cure. Do not allow larger water droplets that drip from nozzles to fall onto the freshly finished plastic concrete. • Cover the concrete with a single layer of clean initial covering immediately after finishing . Apply initial covering no later than 20 minutes after final Pass of the finishing machine and no greater than 20 feet from the back of the finishing machine. Provide an initial covering with a minimum length sufficient to cover the bridge deck from side to side of the concrete placement. Use one of the following: • Saturated wet burlap having a minimum dry weight of 10 ounces per yard for material 40 inches wide. Presoak the burlap by immersing it completely in water for 72 hours prior to the deck placement and presoak new burlap with a wetting agent. Overlap the edges at least 6 inches. • Nonwoven, needle punched polypropylene fabric curing blanket from the QPL. Thoroughly wet fabric within 15 minutes of fabric placement. Overlap the edges at least 12 inches . • Provide soaker hoses for additional soaki ng of the initial covering. Place over the full width of the concrete placement, at a maximum of 10 foot intervals. Do not allow initial wetting of burlap or fabric to dry before soaker hoses are in place and operational. Operate soaker hoses continuous ly to keep the initial covering saturated. • Place a layer of 4 mil polyethylene film over the initial covering and soaker hoses. Provide clear or white polyethylene film if the air temperature is forecasted to be above 65 °F within 24 hours of the concrete placement, and black at other times, as determined by the Engineer. Overlap the edges of polyethylene film by 12 inches . Keep the film in place by taping and weighting the edges where they overlap or are vulnerable to movement by wind. Once a particula r type of film has been placed, do not change it during the curing period. • Maintain a continuous water cure of the concrete surface for 14 Days. (c) Additional Cure Time - If, during the cure time, the Surrounding Temperature falls below 45 °F, extend the cure for the number of hours the temperature is below 45 °F.

00540.52 Removal of Forms and Falsework, and Subsequent Loading - Do not remove F orms

and Falsework or place subsequent loads without approval. In determining when to remove F orms and F alsework, and when to place subsequent loads, the Engineer will consider the Contractor's proposed schedule, the location and character of the Structure , the weather, and other conditions influencing the setting of the concrete. If appropriate, these operations will be controlled by compressive strength tests of cylinders cast by the Contractor and witnessed by the Engineer. Test the cylinders at a recognized testing laboratory at no additional cost 00540.52 493 to the Agency. Cast and cure cylinders according to AASHTO T 23 (field cured) which is equivalent to the most unfavorable field conditions for the portions of the concrete which the cylinders represent. Forms and F alsework may be removed and subsequent loads may be placed when both conditions of Table 00540-1 are met. Table 00540-1

Part 1 — :

Percent of Counting Form and Falsework Removal for: Specified Strength Days 1 Side form for footings, walls, stems, abutments, caps, − 1 traffic and pedestrian barriers, and any other side Forms not supporting the concrete weight Columns − 3 Cantilevered bridge deck sidewalks − 7 Bridge decks supported on steel beams or 80 7 precast, prestressed concrete members; top slabs of concrete box culverts Crossbeams, caps, box girder s, T-beam girders, 80 7 and flat slab Superstructures Arches 2 80 7

Part 2 — :

Percent of Counting Subsequent Loading 3 of: Specified Strength Days 1 Footings for signal, luminaire and sign supports 100 7 Footings 4 − 3 Walls, wall -type abutments, columns, vertical − 3 girder stems, and box culvert stems over 4 feet in height 4 Bottom slabs of box girders 66 5 Members and F alsework designed integrally to 100 7 carry the additional loads Pile caps, bents, and other members designed 100 7 as moment -carrying members All other members 100 7 1 From the time of the last placement in the F orms or Falsework supports and excluding Days when the Surrounding Temperature is below 40 °F for a total of 4 hours or more. 2 Where continuous spans are involved, the time for all spans will be determined by the last concrete placed affecting any span. 00540.53 3 Except loads from F orms and reinforcing steel of further concrete placements. 4 Mass type or other type members where subsequent loading will not induce flexural bending and flexural stresses. Early removal of F orms does not eliminate the curing requirement of 00540.51. Remove Forms and F alsework: • With methods not likely to deface, damage, or cause overstressing of the concrete. • In a manner that permits the concrete to uniformly and gradually take the stresses due to its own weight. • From the interior of structural steel box girders. • From accessible concrete box girder cells before any loading, post -tensioning or removal of the supporting Falsework. • From all decks after subsequent loading is authorized, except those necessary to support the deck slab in inaccessible cells. Dispose of F orms and F alsework according to 00290.20(c).