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<br />~ <br /> <br />. <br /> <br />" <br />. <br /> <br />state. Ensure the concrete is placed and cured in a manner to ensure that the strength and <br />durability of the concrete is maintained. <br /> <br />..., <br /> <br />. <br /> <br />347-2 Materials. <br />347 -2.1 General: Certify that all materials used in concrete are from Department <br />approved sources, and free from frozen or other detrimental matter. <br />Meet the following requirements: <br />(a) Portland Cement ..............................Section 921 * <br />(b) Fine Aggregate...................................Section 902 <br />(c) Coarse Aggregate............................... Section 901 <br />(d) Water............................................... Section 923 <br />(e) Chemical Admixtures ..........................Section 924 <br />(f) Pozzolans and Slag.............................. Section 929 <br />* The heat of hydration requirements of Section 921 is not applicable <br />to nonstructural concrete. Portland cements meeting the requirements of <br />AASHTO M-85 or ASTM C 150 are allowed for nonstructural concrete. <br /> <br />. <br /> <br />II <br /> <br />. <br /> <br />.... <br /> <br />.., <br />. <br /> <br />II <br /> <br />. <br /> <br />., <br /> <br />347-2.2 Admixture Requirements: Chemical admixtures may be added at the <br />dosage rates recommended by the manufacturer. <br />347-2.3 Substitution of Materials: Approved material sources may be substituted <br />for similar materials indicated on the originally approved mix design. Use originally <br />approved mix components and proportions, when unsatisfactory test results are obtained <br />from the use of the substituted material(s). <br />347-2.4 Material Storage: Use a concrete production facility that meets the <br />following requirements: <br />347-2.4.1 Cementitious Materials Storage: Provide a separate and clearly <br />labeled weatherproof facility to store each brand or type of cementitious material without <br />mixing or contamination. Provide a suitable, safe and convenient means of collecting <br />cementitious material samples at each storage facility. <br />347-2.4.2 Aggregate Storage: Provide suitable bins, stockpiles or silos to <br />store and identify aggregates without mixing, segregating or contaminating different <br />grades or types of materials. Identify Department approved pit number and aggregate <br />type/gradation. Handle the aggregates in a manner to minimize segregation and meet the <br />specification requirements when recovered from storage. Continuously and uniformly <br />sprinkle coarse aggregate with water, for 24 hours preceding introduction into the concrete <br />mix. Maintain stored aggregates in a well-drained condition to minimize free water content. <br />Provide access for the Engineer to sample the aggregates from the recovery side of the <br />storage facility. <br /> <br />" <br />. <br /> <br />-, <br />. <br /> <br />.., <br />. <br /> <br />"1 <br /> <br />. <br /> <br />11 <br /> <br />. <br /> <br />n <br />. <br /> <br />. <br /> <br />-, <br /> <br />347-3 Production, Mixing and Delivery. <br />347-3.1 Concrete Production Requirements: Deliver concrete from a production <br />facility that is certified by the National Ready-Mixed Concrete Association (NRMCA) or <br />approved by the District Materials Office. The District Materials Office may inspect the <br />concrete production facility's to verify compliance with the Specifications. Produce <br />concrete utilizing equipment that is in good operating condition and operated in a manner <br />to ensure a consistent product. Within two hours prior to each day's batching, ensure that <br />the concrete production facility determines the free moisture for the coarse and fine <br />aggregates. On concrete placements expected to exceed three hours, perform an additional <br /> <br />. <br /> <br />1"'"1 <br /> <br />. <br /> <br />,.., <br /> <br />. <br /> <br />..... <br /> <br />. <br /> <br />09/09 <br /> <br />01000-109 <br /> <br />03-4122.F <br /> <br />II <br /> <br />- <br />