The Effect of pH Water on the Concrete Mixtures and Curing Condition on the Compressive Strength of Concrete

Abstract

This research examined the effect of acid water as a concrete mix material and as a curing system on the compressive strength of concrete. The effect of wet-dry curing conditions in normal and low pH water on the concrete compressive strength was also evaluated. The water pH of 3 and 7 was conducted in this research. Water pH of 3 was obtained by diluting the HCl solution with tap water. The result showed that the concrete compressive strengths with normal water were 26.23, 26.61, 28.31, and 28.31 MPa at 28, 56, 90, and 120 days, respectively. In comparison, concrete mixed with low pH water was 25.48, 26.04, 26.42, and 26.42 MPa at 28, 56, 90, and 120 days, respectively. The wet-dry curing system for normal water concrete mixed reduced the compressive strength at 28 days by 14.39%, 56 days by 18.44%, 90 days by 14.00%, and 120 days by 10.00%. The wet-dry curing with acidic water also decreased the concrete compressive strength. The wet-dry condition breaks the hydration process between concrete and acid water. Wet-dry curing decreased the compressive strength of concrete. The compressive strength at 28, 56, and 90days decreased 16.30, 12.32, and 7.86%, respectively. While at 120 days, the compressive strength on wet-dry curing slightly increased by 1.43% by 0.01%. Wet-dry curing breaks the concrete hydration process with acid water.