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e <br />1 <br />1 <br />1 <br />1 <br />4. *Note: The "Designated Size" and the corresponding gradations <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. Water shall be clean and free from injurious amounts of oils, acid, <br />alkali, organic matter or other deleterious substances. <br />2. When subjected to the mortar strength test described in ASTM C87, <br />the 28 day strength of mortar specimens made with the water under <br />examination and normal portland cement shall be at least 100 per <br />cent of the strength of similar specimens made with distilled water. <br />3. Potable tap water will normally fulfill the above requirements. <br />4. Raw water (groundwater) and canal water shall not be allowed in the <br />mix. <br />E. Admixtures: <br />A water reducing agent shall be used in all concrete. The admixture <br />shall conform to ASTM Specification C494. Proportioning and <br />mixing shall be as recommended by the 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 specified <br />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 been <br />certified by the local Sealer of Weights and Measures within one year of <br />use. Each size of aggregate and the cement shall be weighed separately. <br />The accuracy of all weighing devices shall be such that successive <br />quantities can be measured to within one percent of the desire amount. <br />Cement in standard packages (sacks) need not be weighed, but bulk <br />cement and fractional packages shall be weighed. <br />B. Water shall be measured by volume or by weight. The water - measuring <br />device shall be capable of control to 1/2% accuracy. All measuring devices <br />shall be subject to approval. Admixtures shall be dispensed either manually <br />with use of calibrated containers or measuring tanks, or by means of an <br />approved automatic dispenser designed by the manufacturer of the <br />specified admixture. <br />03300 -6 03- 4138.0 <br />