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DIVISION 03 Section 03300- Cast-In-Place Concrete � <br /> 2. Continue curing unformed concrete surfaces by water ponding, continuous fog , <br /> spraying, continuously wetted absorptive cover, or by moisture-retaining cover <br /> curing. Cure formed surfaces by moist curing until forms are removed. Keep <br /> concrete continuously moist for not less than 72 hours for high-eazly strength � <br /> concrete and 7 days for all other concrete. <br /> 3.04 FIELD QUALITY CONTROL � <br /> A. Perform sampling and testing during concrete placement as follows: <br /> 1. Sampling Fresh Concrete:ASTM C 172,except modi�ied for slump to comply with ASTM , <br /> C 94. <br /> a. Slump: ASTM C 143.One test at point of dischazge for each day's pour of each ' <br /> type of concrete. Additional tests when concrete consistency seems to have <br /> changed. <br /> b. Air Content: ASTM C 173, volumetric method for lightweight or normal ' <br /> weight concrete; AS.TM C 21, pressure method for normal weight concrete; <br /> one for each day's pour of each type of air-entrained concrete. <br /> c. Concrete Temperature: ASTM C 1064;one test hourly when temperature is 40 � <br /> deg F(4 deg C) and below,when 80 deg F (27 deg C) and above, and one test <br /> for each set of compressive-sirength-specimens. � <br /> d. Compressive Strength Tests:ASTM 39;one set for each day's pour exceeding 5 <br /> cu yd plus additional sets for each 50 cu yd more than the first 25 cu yd of <br /> each concrete class placed in any one day; one specimen tested at 7 days, two � <br /> specimens tested at 28 days, and one specimen retained in reserve for later <br /> testing,if required. <br /> 2. When frequency of testing will provide fewer than five strength tests for a given class of ' <br /> concrete, conduct testing. from attest five randomly selected,batches or firom each batch <br /> if fewer than five are used. � <br /> B. Test results will be reported in writing to Architect,Structural Engineer,ready mix producer, <br /> and Contractor witlun 24 hours after tests. Reports of compressive strength tests shall contain <br /> the Project identification name and number, date of concrete placement, name of concrete , <br /> testing service, concrete type and class, location of concrete batch in structure, design <br /> compressive strength at 28 days, concrete mix proportions and materials, compressive <br /> breaking strength,and type of break for both 7-day tests and 28-day tests. � <br /> C. Nondestructive Testing: Impact hammer, sonoscope, or other nondestructive device may be <br /> permitted but shall not be used as the sole basis for acceptance or rejection. <br /> D.Additional Tests:The testing agency will make additional tests of in-place Concrete when test � <br /> results indicate specified concrete strengths and other characteristics have not been attained <br /> in the structure, as directed by Architect. Testing agency may conduct tests to determine ' <br /> adequacy of concrete by cored cylinders complying with ASTM C 42,or by other methods as <br /> directed. <br /> END OF SECTION 03300 ' <br /> e 03300- 5 � <br /> P� <br /> HENNEPIN COUNTY Orono Sah Stora¢e <br /> March 22,2002 Project No.:0031569 Contract No.:0751R2 , <br />