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D. Water: <br />1. Water shall be clean and free from injurious amounts of oils, <br />acid, alkali, organic matter or other deleterious substances. <br />2. When subjected to the mortar strength test described in ASTM <br />C87, the 28 day strength of mortar specimens made with the <br />water under examination and normal portland cement shall be at <br />least 100 per cent of the strength of similar specimens made <br />' 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 <br />in the mix. <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 <br />shall not be used. Air entraining admixtures with demonstrated <br />compatibility with the concrete mix shall be used as required as <br />a 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 <br />or where other methods are specifically authorized by the Engineer. <br />The apparatus provided for weighing the aggregates and cement shall <br />be suitably designed and constructed for this purpose. Scales shall <br />have been certified by the local Sealer of Weights and Measures <br />within one year of use. Each size of aggregate and the cement shall <br />be weighed separately. The accuracy of all weighing devices shall be <br />such that successive quantities can be measured to within one percent <br />of the desire amount. Cement in standard packages (sacks) need not <br />be weighed, but bulk cement and fractional packages shall be <br />weighed. <br />B. Water shall be measured by volume or by weight. The <br />water - measuring device shall be capable of control to 1/2% accuracy. <br />' All measuring devices shall be subject to approval. Admixtures shall <br />be dispensed either manually with use of calibrated containers or <br />measuring tanks, or by means of an approved automatic dispenser <br />designed by the manufacturer of the specified admixture. <br />1 07/03 03300 -7 03- 3148.A <br />