535Precast, Prestressed Concrete Superstructure

535.01Description This work shall consist of casting and erecting precast/prestressed

concrete products and related material. Materials, work, inspection and documentation not specifically addressed by this Specification shall be done in accordance with the applicable sections of the Precast/Prestressed Concrete Institute (PCI), Manual for Quality Control for Plants and Production of Structural Precast Concrete Products (MNL 116), including Commentary. ALL REQUIREMENTS IN THIS SPECIFICATION ARE THE RESPONSIBILITY OF THE CONTRACTOR, UNLESS NOTED OTHERWISE.

535.02Materials Materials for precast/prestressed concrete products shall meet the

requirements of the following Subsections of the Standard Specifications: Portland Cement and Portland Pozzolan Cement 701.01 W a t e r 701.02 Air-Entraining Admixtures 701.03 Water Reducing Admixtures 701.04 High Range, Water Reducing, Admixture (HRWR) 701.0401 Set-Retarding Admixtures 701.05 F l y A s h 701.10 C a l c i u m N i t r i t e S o l u t i o n 701.11 S i l i c a F u m e 701.12 Ground Granulated Blast Furnace Slag 701.13 F i n e A g g r e g a t e f o r C o n c r e t e 703.01 C o a r s e A g g r e g a t e f o r C o n c r e t e ( C l a s s A , A A o r L a t e x ) 703.02 Reinforcing Steel 709.01 W e l d e d S t e e l W i r e F a b r i c 709.02 S t e e l S t r a n d 709.03 Portland cement shall conform to AASHTO M85 (ASTM C150), Type I, Type II, or Type III or AASHTO M 240. Supply the Department with copies of Certified Mill Test Reports for the cement. Provide a Materials Certification from the manufacturer of the prestressing strand. The certification shall include a representative load elongation curve for each coil. The manufacturer shall identify each coil of strand. Do not remove the identification from the coil. Partial coils may be used with the approval of the Fabrication Engineer. Failure to maintain traceability of a coil will be cause for rejection. Provide Certified Mill Test Reports for the reinforcing steel, welded wire fabric and fusion bonded epoxy coating.

535.03Working Drawings Prepare shop detail, erection and other necessary Working

Drawings in accordance with Section 105.7, Working Drawings. The Department will review the drawings in accordance with the applicable requirements of Section 105.7, Working Drawings. Changes and revisions to the reviewed Working Drawings will require further review by the Fabrication Engineer. Concrete mix designs shall be part of the Working Drawing submittal. Include aggregate specific gravity, absorption, percent fracture, fineness modulus and gradation as part of the mix design. Provide the mix design calculations demonstrating how the batch weights, water-cement ratio and admixture dosage rate were determined.

535.04Plant The plant shall be a PCI Certified facility

535.05Facilities for Inspection Provide a private office at the fabrication plant for the

Department’s inspection personnel, or Quality Assurance Inspectors (QAI’s). The office shall be in close proximity to the Work. The office shall be climate controlled to maintain the temperature between 68° F and 75° F and have the exit(s) closed by a door(s) equipped with a lock and 2 keys which shall be furnished to the QAI’s. The QAI’s office shall meet the following minimum requirements: Description Q u a n tity Office area (minimum ft2) 100 Drafting table surface (ft2) 3 5 Drafting stools-each 1 O f f i c e d e s k 1 Ergonomic swivel chairs 1 Folding chairs 2 High-speed internet connection (ports) o r w i r e l e s s 1 Fluorescent lighting of 100 ft-candles minimum for all work areas 2 110 Volt 60 cycle electric wall outlets 3 W a l l c l o s e t 1 Waste basket with trash bags 1 B r o o m 1 D u s t p a n 1 Water cooler 1 Cleaning materials-floor, surfaces, windows, for duration of the project The Contractor will be responsible for disposing of trash and supplying commercially bottled water for the water cooler. The QAI will have the option to reject any furniture or supplies provided to the QAI’s office, based on general poor condition. Provide parking space for the QAI(s) in close proximity to the entrance to the QAI’s office. Maintain the pathway between the parking area and the QAI’s office so that it is free of obstacles, debris, snow and ice. The facilities and all furnishings shall remain the property of the Contractor upon completion of the Work. Payment for the facilities, heating, lighting, internet connection and monthly internet charges and all furnishings shall be incidental to the Contract. Failure to comply with the above requirements will be considered denial of access to the Work for the purpose of inspection. The Department will reject all Work done when access for inspection is denied.

535.06Notice of Beginning Work Give the Department a minimum of two weeks notice

for in-Maine work and three weeks notice for out-of-Maine work, prior to beginning production. If the production schedule changes, notify the Fabrication Engineer no less than 3 working days prior to the initial start-up date. Any Work done without the QAI present will be rejected. Advise the Fabrication Engineer of the production schedule and any changes to it. If Work is suspended on a project, the Fabrication Engineer will require 72 hours notice prior to the resumption of Work.

535.07Quality Control Quality Control (QC) is the responsibility of the Contractor

Provide a copy of the Quality System Manual (QSM) to the Fabrication Engineer, if requested. Calibrate all production equipment in accordance with MNL 116, except that stressing jacks shall be calibrated every 6 months. Provide calibration certifications to the QAI prior to beginning fabrication. Calibrate scales, admixture dispensers and water gauges at the frequency specified in MNL 116. Use proving rings, load cells and solid standard weights, as applicable. The calibration shall be performed by a testing laboratory acceptable to the Department using calibration equipment the accuracy of which is traceable to a National Institute of Standards and Technology (NIST) standard. Quality Control Inspectors (QCI’s) shall have a valid PCI Quality Control Certification Level I, Level II or Level III. Personnel performing concrete testing shall hold a current ACI Field Testing Technician Grade I Certification, or equivalent. Inspect all aspects of the Work in accordance with the Contractor’s QSM. Reject materials and workmanship that do not meet Contract requirements. Record measurements and test results on the appropriate forms from APPENDIX E of MNL 116, or an equivalent form prepared by the user. Provide copies of measurements and test results to the QAI as follows: Type of Report When Provided to QAI* Aggregate gradations-fine aggregate and coarse Prior to beginni ng work and at least once a aggregate week thereafter Material certifications / stressing calculations / calibration certifications Prior to beginning work (anticipate adequate time for review by QAI) Tensioning report The same work day Pre-placement inspection report Prior to the concrete placement Concrete batch slips The morning of the next work day Results of concrete testing The morning of the next work day Results of compressive strength testing (for release) The same work day Concrete temperature records Provide with compressive strength testing (for release) Nonconformance reports/repair procedures Within 24 hours of dis covery Results of compressive strength testing (for design strength) Prior to stopping curing Post-placement inspection report Within 48 hours of achieving d esign strength * The Contractor and QAI may, by mutual agreement, modify any part of the schedule; however, failure to provide the documentation when required by the Fabrication Engineer will result in the product being deemed unacceptable. The Contractor may perform testing in addition to the minimum required. The results of all testing shall be made available to the Department.

535.08Quality Assurance Quality Assurance (QA) is the prerogative of the Department

The QAI will perform acceptance sampling and testing and will witness or review documentation, workmanship and testing to assure the Work is being performed in accordance with the Contract Documents. The QAI has the authority to reject materials and products that do not meet the Contract requirements, including Work rejected due to denial of access or the lack of adequate notice of the beginning of production. The acceptance of material or workmanship by the QAI will not preclude subsequent rejection, if found unacceptable by the Department, at a later date.

535.09Nonconforming Work Correct or replace nonconforming material and/or

workmanship. Generate a nonconformance report (NCR) describing the nonconformance and the proposed corrective action; provide a copy to the QAI and forward a copy to the Fabrication Engineer for review. In the event that an item does not meet the Contract requirements but is deemed suitable for use by the Department, said item may be accepted in accordance with Section 106.8, Non-Conforming Work, of the Standard Specifications.

535.10Forms and Casting Beds Construct forms in accordance with the Working

Drawings. The forms shall be well constructed, carefully aligned and sufficiently tight to prevent leakage of mortar. Reject forms that do not maintain the dimensions shown on the Working Drawings. Inspect the bulkheads after each cast and repair or replace worn or damaged pieces. Seal wooden forms to prevent absorption of water. Apply and cure the sealer in accordance with the manufacturer's product data sheet. Remove all paint, adherent material, foreign matter and debris prior to placing concrete. Apply a non-staining bond-breaking compound to the forms in accordance with the manufacturer's product data sheet. Solvent clean reinforcing steel and strand contaminated with the bond-breaking compound.

535.11Reinforcing Steel Fabricate, package, handle, store, place, splice and repair

reinforcing steel in accordance with Section 503 of the Standard Specifications. Accurately locate and securely anchor the reinforcing steel to prevent displacement during concrete placement. Install and secure all reinforcing steel prior to beginning the concrete placement. The concrete cover shown on the reviewed Working Drawings shall be the minimum allowable cover. Use sufficient bar supports and spacers to maintain the minimum concrete cover. The bar supports and spacers shall be made of a dielectric material or other material approved by the Fabrication Engineer.

535.12Voids and Inserts Voids shall be non-absorbent. The out-to-out dimensions of

the voids shall be within 2 percent of Plan dimensions. Repair damaged voids in a manner acceptable to the Fabrication Engineer. Store, handle and place voids in a manner that prevents damage. Accurately locate and securely anchor, securely cap and vent the voids in the form. Any portion of a void that is displaced beyond the allowable dimensional tolerances shall be cause for rejection of the slab or beam. Open the void drains immediately upon removing the product from the form. Recess inserts 1 inch, unless noted otherwise on the Plans. The Department is not responsible for verifying the location of inserts or other hardware installed for the convenience of the Contractor.

535.13Concrete New concrete mix designs and mix designs not previously approved by

the Fabrication Engineer shall be qualified by trial batches prepared in accordance with AASHTO T 126 (ASTM C192). The test results shall demonstrate that the concrete meets the requirements of the Plans and this Specification. If accelerated curing is to be used in production, the test specimens shall be similarly cured. The concrete mix design shall meet the following requirements: Minimum cement content 658 lbs./cubic yard Water-cement ratio * 0.40 (maximum) Air entrainment 5-½ % to 7-½ % Allowable Slump Flow for Self- Consolidating Concrete (SCC) 20 inches to 30 inches Visual Stability Index(VSI) for SCC VSI of 0 or 1, per ASTM C16 11. If a mortar paste halo is present, it shall not exceed 0.25 inch. Corrosion inhibitor ** 3 gal. /c.y. (unless otherwise specifie d) Silica Fume (when used) 5% to 10% of cement content by weight Fly Ash (when used) 40% of cementitious material (maximum) Slag (when used) 50% of cementitious material (maximum) * For the purpose of calculating water cement ratios, one U.S. gallon of water shall be considered to weigh 8.34 pounds. ** The water in the corrosion inhibitor solution shall be included when calculating the water-cement ratio. The concrete mix design shall be proportioned so that the concrete achieves transfer strength within twenty four hours of the completion of the placement if the release strength is 6,000 psi, or less. If two consecutive placements fail to meet the above requirements, no further placements shall take place until corrective action is taken by the Contractor.

535.14Concrete Placement Do not batch or place concrete until all the form(s) for any

continuous placement have been inspected and accepted by the QCI, and the QAI concurs. Test concrete in accordance with the following Standards: AASHTO T 22 (ASTM C39) Test Method for Compressive Strength of Cylindrical Concrete Specimens AASHTO T23 (ASTM C31) Practice for Making and Curing Concrete Test Specimens in the Field AASHTO T141 (ASTM C172) Practice for Sampling Freshly Mixed Concrete AASHTO T152 (ASTM C231) Test Method for Air Content of Freshly Mixed Concrete by the Pressure Method AASHTO T196 (ASTM C173) Standard Test Method for Air Content of Freshly Mixed Concrete by the Volumetric Method ASTM C1064 Test Method for Temperature of Freshly mixed Portland Cement Concrete ASTM C1611 Standard Test Method for Slump Flow of Self-Consolidating Concrete Test the first two loads of concrete for temperature, air entrainment and slump flow for SCC. If the first load is unacceptable, test the second load as the first. Continue this process until two consecutive loads are acceptable. After two consecutive loads are acceptable, the frequency of testing shall be at the discretion of the QAI. If there is a change in the dosage rate of any admixture or a change of more than 5 F in mix temperature, then test the concrete for temperature, air entrainment and slump flow for SCC. Test every load of 1 cubic yard, or less, from a stationary mixer or 2 cubic yards, or less, from a transit mixer for temperature, air entrainment and slump flow for SCC, prior to placing the concrete in the forms. Perform all testing in the presence of the QAI. The QAI will designate the loads to be tested. Make cylinders used to determine release strength during the last one-third of the placement. Place the concrete as nearly as possible to its final location. Control the depth of each lift in order to minimize entrapped air voids. The maximum depth of an unconsolidated lift shall be 18 inches. Vibrate the concrete with internal or internal and external vibrators. Do not use external vibrators, only. Insert internal vibrators vertically and penetrate the lower layer of concrete by at least 4 inches. Insert the vibrators in the concrete to assure that the radii of action of the vibrators overlaps. Hold the vibrators in position from 5 to 15 seconds; vibration time shall be reduced by 50 percent when placing SCC. Do not use vibrators to move concrete horizontally. Each lift of concrete shall have sufficient plasticity to be consolidated with subsequent lifts. Do not re-temper the concrete with water after discharging has begun. The Contractor may add HRWR to the concrete after batching, if that practice conforms to the manufacturer's product data sheet. Discard concrete that becomes unworkable. Do not use water or water-based products to aid in finishing fresh concrete. After the concrete has been placed and finished, and before the forms are covered, remove all concrete from projecting reinforcing steel. Measure and record the concrete cover at each void location after void hold-downs have been removed. The QAI will indicate the number and location of the measurements.

535.15Acceptance and Quality Control Testing of Concrete Acceptance of structural

precast/prestressed units, for each day’s production, will be determined by the Department, based on compliance with this specification and satisfactory concrete testing results. At least once per week, the QAI will make 2 concrete cylinders (6 cylinders when the Contract includes permeability requirements) for use by the Department; cylinders shall be standard cured in accordance with AASHTO T23 (ASTM C31). The QAI will perform entrained air content and slump flow testing, determine water-cement ratio and determine temperature of the sampled concrete at the time of cylinder casting. All testing equipment required by the QAI to perform this testing shall be provided in accordance with Standard Specification Section 502.041, Testing Equipment. In addition, the Contractor shall provide a slump cone meeting the requirements of AASHTO T 119. Providing and maintaining testing and curing equipment shall be considered incidental to the work and no additional payment will be made. Quality Control concrete test cylinders shall be made for each day’s cast and each form bed used. Cylinders tested to determine strand release strength and design strength shall be field cured in accordance with AASHTO T23 (ASTM C31). 28 day cylinders shall be standard cured. Record unit identification, entrained air content, water-cement ratio, slump flow and temperature of the sampled concrete at the time of cylinder casting If the Contractor fails to make enough cylinders to demonstrate that the product meets the Contract requirements, the product will be considered nonconforming work. The compressive strength of the concrete will be determined by averaging the compressive strength of two test cylinders made from the same sample. For the purpose of detensioning prestressed products, neither of the test cylinders shall have a compressive strength less than the minimum required transfer strength. For the purpose of determining design strength, the average of two cylinders shall meet or exceed the design strength, and the difference in strength between the two shall be no more than 10 percent of the higher strength cylinder. Perform compressive strength testing to determine transfer and design strength in the presence of the QAI. Cylinder tests not witnessed by the QAI will not be acceptable.

535.16Curing by Moisture Retention Cure the concrete in accordance with MNL 116,

Section 4.20. Moist cure the concrete until it has reached design strength. Do not use membrane- forming curing compounds without the approval of the Fabrication Engineer. If membrane-forming curing compounds are authorized, follow the requirements of MNL 116 and the curing compound manufacturer’s published recommendations.

535.17Accelerated Curing of Concrete (Optional) Cure the concrete in accordance with

MNL 116, Section 4.19, except as modified herein. After initial set, the temperature gain of the concrete shall not exceed 40F per hour. Initial set shall be determined in accordance with ASTM C403, Standard Test Method for Time of Setting of Concrete Mixtures by Penetration Resistance; a strength gain of 500 psi indicates initial set. The maximum allowable concrete temperature shall be 160F. Concrete temperature shall be measured near each end of the casting bed and at intervals not to exceed 100 feet. In order to qualify for accelerated cure, the concrete temperature shall attain a minimum temperature of 120F; that temperature shall be maintained for a minimum of 8 hours and the concrete shall achieve a minimum of 80 percent of design strength. Detension precast/prestressed products immediately after the completion of the curing cycle while the products are warm and moist. The accelerated curing cycle shall be considered complete when the method of supplying heat is stopped and/or the concrete temperature drops below 120°F. Two cylinders shall be tested immediately upon completion of the accelerated cure cycle. Products that have not achieved all of the above criteria shall be moist cured until the concrete has achieved design strength. If the precast/prestressed concrete products have achieved 80 percent of design strength during the accelerated curing cycle, no further curing will be required.

535.18Prestressing Tension the strands in accordance with MNL 116 and this

Specification. Provide stressing calculations to the QAI prior to tensioning strands. Do not tension the strands until the QAI has reviewed the calculations. Apply initial force and final force to the strands in the presence of the QAI. The QCI shall be present to monitor and document the application of initial force, final force and the elongation of the strands. Tension strands in an orderly sequence to avoid snags and entanglements. When strands from two, or more, coils are used, identify the locations of the different strand lots. Calculate the elongation and adjusted gauge pressure readings for each modulus of elasticity and cross sectional area of the strands. Prior to tensioning, cycle the hydraulic jacking devices until the hydraulic fluid reaches normal operating temperature. After initial tensioning, establish a permanent and clearly visible reference mark on the strand to determine strand elongation after final tensioning. Measure the strand elongation to the nearest 1/16 inch. If the strands have been tensioned for more than 48 hours without concrete being placed in the forms, test a minimum of 10 percent of the strands, but not less than two strands in each row and not less than two strands in draped strand arrays, by applying the theoretical force used during the final tensioning to each of the strands. If additional elongation is gained, subtract the amount gained from the theoretical elongation. If the result of the theoretical elongation minus the gain in elongation is less than the minimum allowable elongation for any of the strands tested, apply the final force to all strands. Do not measure total elongation from the original reference mark. Accept properly tensioned strand based on the force applied to the strands. Measure and record the chuck-to-chuck distance on self-stressing beds after tensioning the first set-up and at any time the number of strands or strand array changes. Confirm that the measurement used in the stressing calculations is the same as the field measurement.

535.19Detensioning Detension the strands in accordance with MNL 116 and this

Specification. Use a carburizing flame. Heat a minimum length of 6 inches of the strand slowly so that only one wire is released at a time. Cut both ends and any intermediate points simultaneously. Failure to maintain symmetry of cutting or causing sudden shock to the product will make it subject to rejection. Detension the strands in the presence of the QAI and QCI. Measure any strand slippage on all precast/prestressed concrete products. Mark all strands prior to detensioning. Measure a minimum of four strands per row. The QAI will choose the strands to be measured.

535.20Finishing Concrete and Repairing Defects Precast/prestressed concrete products

fabricated under this Section shall meet Standard Grade finish requirements as defined in MNL 116, except that the Contractor shall rub fascia units in accordance with Section 502 of the Standard Specifications. Abrasive blast fascia surfaces prior to finishing. The Contractor may use alternative methods of achieving an acceptable finish on fascia units, if approved by the Fabrication Engineer. Repair honeycombing, ragged or irregular edges and other non-structural or cosmetic defects using a patching material from the Department Qualified Products List (QPL). The repair, including preparation of the repair area, mixing and application and curing of the patching material, shall be in accordance with the manufacturer's product data sheet. Corners that are not exposed in the final product may be ground smooth with no further repair necessary if the depth of the defect does not exceed 1/2 inch. Remove form ties and other hardware to a depth of not less than 1 inch from the face of the concrete and patch the holes using a patching material from the Department QPL. Repair structural defects only with the approval of the Fabrication Engineer. Submit a nonconformance report (NCR) to the Fabrication Engineer with a proposed repair procedure. Do not perform structural repairs without an NCR that has been reviewed by the Fabrication Engineer. Structural defects include, but are not be limited to, exposed reinforcing steel or strand, cracks in bearing areas, through cracks and cracks 0.013 inch in width that extend more than 12 inches in length in any direction. Give the QAI adequate notice prior to beginning any structural repairs. Make chamfers and drip notches smooth and uniform. Sandblast keyways to remove mortar paste prior to shipping. Recess strand ends 1 inch and patch the holes with a patching material from the Department QPL. Coat the entire ends of the precast/prestressed concrete units with a bituminous protective coating unless otherwise specified on the Plans or as directed by the Fabrication Engineer.

535.21Precast/prestressed Deck Panels Produce precast/prestressed deck panels in

accordance with the Plans and Specifications. Cure the deck panels in accordance with Sections 535.16 or 535.17.

535.22Tolerances Product dimensional tolerances shall be in conformance with the

latest edition of MNL 116, Appendix B, as applicable to the particular product (e.g., slab, I- girder. box beam), the Plans and this Specification. Use Box Beam fabrication tolerances for voided slabs and use Double T tolerances for NEXT beams. In case of dispute, the Fabrication Engineer shall determine the allowable tolerance.

535.23Transportation and Storage Handle and store material using lifting devices

Handle and transport precast/prestressed units so that the reactions with respect to the unit shall be approximately the same during transportation and storage as in its final position. Do not transport units until the 28 day design strength has been attained. Support stored precast/prestressed units above the ground on dunnage in a manner to prevent twisting or distortion. Protect the units from discoloration and damage. Repair or replace precast/prestressed concrete units damaged by improper storing, hoisting or handling.

535.24Installation of Slabs, Beams and Girders Finish bearing areas to the elevations

shown on the Plans and in accordance with Section 523, Bearings, as applicable. Lift the units using the lifting devices cast into them. Support I-Girders at the abutments and piers to prevent overturning. Place beams and slabs in their final location in a manner that assures that the keyways are spaced properly and the post-tensioning ducts are in alignment. Use compressible gaskets around duct openings within keyways to prevent blocking of the duct with grout. Prior to grouting, initially post-tension slabs or beams to 5,000 lbs. force, per strand. Make a permanent and clearly visible reference mark on each strand after it has been initially post-tensioned in order to determine strand elongation after final post-tensioning. Immediately prior to grouting, clean the keyways between slab or box units and soak the keyways with water in order to prevent absorption of water from the grout. Seal the bottom of the keyways to prevent the loss of grout. Fill longitudinal keyways between slabs or beams with a non-shrink, flowable, cementitious grout with a minimum design compressive strength of 6,000 psi at 28 days. The grout shall be a material for keyways from the Department QPL. Mix, place and cure the grout in accordance with the manufacturer's product data sheet. The Contractor may propose the use of an alternate grout material supplied from a Department approved ready mixed concrete batch plant. Ready mixed grout shall achieve a design compressive strength of 6,000 psi at 28 days, have an entrained air content of between 6.0 and 9.0 percent, be non-shrink, flowable, and contain a non-shrink additive listed on the Department QPL for expansive cements. The proposed grout mix design shall be submitted to the Department for approval. Do not perform final post-tensioning of slabs or beams less than 24 hours after completion of the grouting operation. Final post-tension precast/prestressed concrete slabs or beams to 41,000 lbs. force per strand, unless otherwise specified on the Plans. Provide a jacking device that has been calibrated in accordance with MNL 116. Provide calibration documentation, a calibration curve and stressing calculations to the Resident, allowing adequate time for review. Do not post-tension slabs or beams until the documentation has been reviewed by the Department. Post-tension the slabs or beams in the presence of the Resident. No vehicular traffic, including the Contractor’s equipment, shall be allowed on the bridge until post-tensioning is complete. Saw cut or abrasive cut the post-tensioning strand of slabs or beams no closer than 1-¼ inches from the wedges after tensioning is complete. Coat the strand ends and wedges with a corrosion inhibiting grease and cap the ends with a watertight cover. Pack and neatly finish the post-tensioning recesses of slabs or beams with a grout made of the same brand and type of cement used to cast the slabs or beams. Clean the post- tensioning recesses prior to packing the grout.

535.25Installation of Precast/Prestressed Deck Panels Erect deck panels as shown on

the Plans or reviewed Working Drawings, as applicable. Adjust the bottom-of-slab elevation using threaded jacking devices cast into the panels, or by other means approved by the Resident. Fill the voids between the top of the beam and the bottom of the panels, as shown on the Plans, reviewed Working Drawings or Standard Details, as applicable, with a non-shrink, flowable, cementitious grout with a minimum design compressive strength of 6,000 psi at 28 days. The grout shall be a material for keyways from the Department QPL. Mix, place and cure the grout in accordance with the manufacturer’s published product data sheet. Provide vent holes at 3-foot intervals to avoid air locks. The Contractor may propose the use of an alternate grout material supplied from a Department approved ready mixed concrete batch plant. Ready mixed grout shall achieve a design compressive strength of 6,000 psi at 28 days, have an entrained air content of between 6.0 and 9.0 percent, be non shrink, flowable, and contain a non shrink additive listed on the Department QPL for expansive cements. The proposed grout mix design shall be submitted to the Department for approval. Prevent concrete leakage between the deck panels using caulking, backer rod or other methods approved by the Resident. Remove all visible contaminants from the deck panels and protruding reinforcing steel by abrasive blast cleaning or high pressure (minimum of 8,000 psi) water cleaning, prior to placing the deck concrete.

535.26Method of Measurement Prestressed structural concrete items will be measured

by the lump sum, except that precast deck panels will be measured as part of the structural concrete slab Pay Item(s).

535.27Basis of Payment Acceptable work done under Precast, Prestressed Concrete

Superstructure will be paid for at the Contract lump sum price for the respective Pay Item; all work associated with precast deck panels will be considered incidental to the structural concrete slab Pay Item(s). Payment will be full compensation for furnishing all materials, labor and equipment in the precast/prestressed work, including concrete, strand, reinforcing steel, anchor dowels and related items. Related items will include, but not be limited to: Working Drawings, preformed pads, transportation, erecting the units, drilling and grouting of anchor dowels, grouting of keyways, panels and ducts, tensioning and post-tensioning operations, and required concrete admixtures. Payment will be made under: P a y I t e m P a y U n i t

535.60Prestressed Structural Concrete Slab L u m p S u m

535.61Prestressed Structural Concrete I-Girders L u m p S u m

535.62Prestressed Structural Concrete Box Beams Lump Sum

2 Prestressed Structural Concrete NEXT Beam Lump Sum

Chapter 6 DIVISION 600 - MISCELLANEOUS CONSTRUCTION