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3. The following designated sizes* of aggregate shall be the maximum <br />employed in concrete: <br />F, <br />F, <br />E. Admixtures: <br />1. A water reducing agent shall be used in all concrete. The <br />admixture shall conform to ASTM Specification C494. <br />Proportioning and mixing shall be as recommended by the <br />manufacturer. <br />2. Admixtures causing accelerated setting of cement in concrete shall <br />not be used. Air entraining admixtures with demonstrated <br />compatibility with the concrete mix shall be used as required as a <br />moderate addition to the water reducing agent to obtain the <br />specified percent air in the resultant concrete. <br />PART 3 - EXECUTION <br />3.01 MEASURING MATERIALS <br />A. Materials shall be measured by weighing except as otherwise specified or <br />where other methods are specifically authorized by the Engineer. The <br />apparatus provided for weighing the aggregates and cement shall be <br />suitably designed and constructed for this purpose. Scales shall have <br />been certified by the local Sealer of Weights and Measures within one <br />year of use. Each size of aggregate and the cement shall be weighed <br />separately. The accuracy of all weighing devices shall be such that <br />successive quantities can be measured to within one percent of the desire <br />amount. Cement in standard packages (sacks) need not be weighed, but <br />bulk cement and fractional packages shall be weighed. <br />December 2006 03300 -7 06 -5723 <br />2 inch for plain concrete <br />1 inch for reinforced sections 10 inch and over in thickness <br />3/4 inch for reinforced sections less than 10 inch in thickness <br />*Note: "Designated <br />4. <br />The Size" and the gorres ondin gradations <br />p <br />shown represent the end or combined gradation of the coarse <br />aggregate to be used in the final concrete. <br />D. Water: <br />1. <br />Water shall be clean and free from injurious amounts of oils, acid, <br />alkali, organic matter or other deleterious substances. <br />2. <br />When subjected to the mortar strength test described in ASTM <br />C87, the 28 day strength of mortar specimens made with the water <br />under examination and normal portland cement shall be at least <br />100 per cent of the strength of similar specimens made with <br />distilled water. <br />3. <br />Potable tap water will normally fulfill the above requirements. <br />4. <br />Raw water (groundwater) and canal water shall not be allowed in <br />the mix. <br />F, <br />F, <br />E. Admixtures: <br />1. A water reducing agent shall be used in all concrete. The <br />admixture shall conform to ASTM Specification C494. <br />Proportioning and mixing shall be as recommended by the <br />manufacturer. <br />2. Admixtures causing accelerated setting of cement in concrete shall <br />not be used. Air entraining admixtures with demonstrated <br />compatibility with the concrete mix shall be used as required as a <br />moderate addition to the water reducing agent to obtain the <br />specified percent air in the resultant concrete. <br />PART 3 - EXECUTION <br />3.01 MEASURING MATERIALS <br />A. Materials shall be measured by weighing except as otherwise specified or <br />where other methods are specifically authorized by the Engineer. The <br />apparatus provided for weighing the aggregates and cement shall be <br />suitably designed and constructed for this purpose. Scales shall have <br />been certified by the local Sealer of Weights and Measures within one <br />year of use. Each size of aggregate and the cement shall be weighed <br />separately. The accuracy of all weighing devices shall be such that <br />successive quantities can be measured to within one percent of the desire <br />amount. Cement in standard packages (sacks) need not be weighed, but <br />bulk cement and fractional packages shall be weighed. <br />December 2006 03300 -7 06 -5723 <br />