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EFFECT OF WATER TEMPERATURES ON THE COMPRESSIVE STRENGTH, SLUMP AND SETTING TIME OF CONCRETE
Authors: UMEONYIAGU IKECHUKWU ETIENNE
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ABSTRACT- This research conducted in Eastern Nigeria was aimed at determining the effects of mixing-water temperature on the compressive strength, workability and setting time of concrete. The river sand used was from River Otamiri and granite stones from Abakaliki were used as the coarse aggregates. These materials were prepared based on BS 812: 1987, BS410:1986 and BS 1881:1983. The temperatures of the water used were variously: – 50C, 100 C, 150C, 280C, 350C, 450C, 500C, 600C, 700C, 750C, 900C and 1000C. The mix ratio of 1:2:4 with water –cement ratio of 0.58 by weight of concrete was used. It was found that the compressive strengths were increasing as the age increased. This increase reached a peak of 33.65Mpa at 500C after which the strength declined gradually to as low as 1.97Mpa at a water temperature of 1000C. In terms of workability, the workability of the concrete increased as the temperature of the mixing-water increased, getting to a high of 175mm slump at 1000C and became constant for temperatures between 280C – 500C. For setting time, the setting time of the paste increased with the rise in temperature of the mixing water. The study has revealed that water temperature has a significant influence on the strength, workability and setting time of concrete. Also, it was shown that the optimal temperature to achieve a high strength at 28 days was 500C