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PGSF WMVD Storm and Combined Sewer - Construction Package 2 Cast-in-Place Concrete <br />Project No. 180162 03 30 00 - 13 <br /> <br />C. Curing and sealing compound shall be certified compliant with final finish system if <br />applicable, including compatibility with floor hardeners in areas where floor hardeners <br />are specified to be used. <br />PART 3 EXECUTION <br />3.01 GENERAL <br />A. Use only truck-mixed, ready-mixed concrete conforming to ASTM C94. Proportion <br />materials by weighing. <br />B. Introduce pozzolan into the mixer with cement and other components of the concrete <br />mix; do not introduce pozzolan into a wet mixer ahead of other materials or with mixing <br />water. <br />C. Introduce water at the time of charging the mixer; additional water may be introduced <br />within 45 minutes from charging the mixer, provided the specified w/c ration and slump <br />is not exceeded and the maximum total water per the approved mix design is not <br />exceeded. <br />D. Arrange with the testing laboratory for inspection as required to comply with these <br />specifications. <br />E. Deliver concrete to the site and complete discharge within 90 minutes after introduction <br />of water to the mixture. Extension of allowable time beyond this limit requires a <br />Contractor proposed remedial action plan to be reviewed and accepted by the Owner’s <br />Representative. <br />3.02 CONVEYING AND PLACING CONCRETE <br />A. Convey concrete from the mixer to the forms in accordance with ACI 301. Remove <br />concrete that has segregated in conveying from the site of the work. <br />B. Placing Concrete: <br />1. General: <br />a. Place concrete in accordance with ACI 301. Do not permit concrete to drop freely <br />more than 4-ft (6-ft when superplasticizer is used). <br />2. Placing Concrete By Pumping: <br />a. Concrete placed by pumping is at Contractor’s discretion and shall not be the <br />cause to change or relax specified mix design characteristics. Concrete shall <br />possess the specified characteristics at the point of placement. <br />b. Measure slump at the hose discharge, except as follows: Initial slump testing in <br />each placement shall occur at both the pumping unit inlet hopper and hose <br />discharge. Slump loss in pumping, measured between the inlet hopper and the <br />hose discharge, shall not exceed 1 inch. After these criteria have been satisfied, <br />slump may be measured at the inlet hopper with allowable slump increased by <br />the earlier measured difference, not to exceed 1 inch.