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conformance with the requirements in ASTM Designation: C 109, when compared to the results obtained with distilled <br /> water or deionized water,tested in conformance with the requirements in ASTM Designation: C 109. <br /> • In nonreinforced concrete work, the water for curing, for washing aggregates and for mixing shall be free from oil <br /> and shall not contain more than 2000 parts per million of chlorides as Cl, when tested in conformance with California <br /> Test 422,or more than 1500 parts per million of sulfates as SO4,when tested in conformance with California Test 417. <br /> • In addition to the above provisions, water for curing concrete shall not contain impurities in a sufficient amount to <br /> cause discoloration of the concrete or produce etching of the surface. <br /> • Water reclaimed from mixer wash-out operations may be used in mixing concrete. The water shall not contain <br /> coloring agents or more than 300 parts per million of alkalis(Na2O+0.658 K2O)as determined on the filtrate. The specific <br /> gravity of the water shall not exceed 1.03 and shall not vary more than±0.010 during a day's operations. <br /> 90-2.04 ADMIXTURE MATERIALS <br /> • Admixture materials shall conform to the requirements in the following ASTM Designations: <br /> A. Chemical Admixtures—ASTM Designation: C 494. <br /> B. Air-entraining Admixtures—ASTM Designation: C 260. <br /> 90-3 AGGREGATE GRADINGS <br /> 90-3.01 GENERAL <br /> • Before beginning concrete work,the Contractor shall submit in writing to the Engineer the gradation of the primary <br /> aggregate nominal sizes that the Contractor proposes to furnish. If a primary coarse aggregate or the fine aggregate is <br /> separated into 2 or more sizes,the proposed gradation shall consist of the gradation for each individual size,and the proposed <br /> proportions of each individual size, combined mathematically to indicate one proposed gradation. The proposed gradation <br /> shall meet the grading requirements shown in the table in this section,and shall show the percentage passing each of the sieve <br /> sizes used in determining the end result. <br /> • The Engineer may waive, in writing, the gradation requirements in this Section 90-3.01 and in Sections 90-3.02, <br /> "Coarse Aggregate Grading," 90-3.03, "Fine Aggregate Grading," and 90-3.04, "Combined Aggregate Gradings," if, in the <br /> Engineer's opinion,furnishing the gradation is not necessary for the type or amount of concrete work to be constructed. <br /> • Gradations proposed by the Contractor shall be within the following percentage passing limits: <br /> Primary Aggregate Nominal Size Sieve Size Limits of Proposed Gradation <br /> 37.5-mm x 19-mm 25-mm 19-41 <br /> 25-mm x 4.75-mm 19-mm 52-85 <br /> 25-mm x 4.75-mm 9.5-mm 15 -38 <br /> 12.5-mm x:4.75-mm 9.5-mm 40-78 <br /> 9.5-mm x 2.36-mm 9.5-mm 50-85 <br /> Fine Aggregate 1.18-mm 55-75 <br /> Fine Aggregate 600-µm 34-46 <br /> Fine Aggregate 300-µm 16-29 <br /> • Should the Contractor change the source of supply, the Contractor shall submit in writing to the Engineer the new <br /> gradations before their intended use. <br /> 90-3.02 COARSE AGGREGATE GRADING _ <br /> • The grading requirements for coarse aggregates are shown in the following table for each size of coarse aggregate: <br /> Contract No. 10-OM7104 <br /> 75 <br />