Pengaruh Beton Mutu Tinggi dengan Substitusi Fly Ash Pasca-Curing menggunakan H2so4

Abstract

This research was intended to (1) design high-strength concrete with fly ash as a substitute for type I Portland cement, (2) determine the workability of fly ash-substituted high-strength concrete, and (3) determine the mechanical behavior of post-curing concrete with sulfuric acid. The method used in this research is the experimental method. In this research, fly ash from PLTU Pangkalan Susu was used as a substitute for cement in high-strength concrete with fly ash content variations of 10%, 20%, 30%, 40%, and 50% with cylinders measuring ∅ 150 mm and 300 mm high with a concrete quality plan. The specimens that have been finished will be tested by curing with a H2SO4 concentration of 4% for 28 days. Subsequently, the compressive strength and split tensile strength of concrete can be tested. Based on the results of this research, it is concluded that the 10% fly ash substrate variation is the most optimal for being in the sulphate environment compared to other variations in accordance with each test carried out in the research. The compressive strength value of the concrete in the 10% variation is 64.1 MPa, followed by the split tensile strength value of the concrete in the 10% variation of 3.9 MPa. This was due to the fact that the addition of fly ash to concrete can reduce the content of calcium hydroxide (Ca(OH)2), which causes concrete to reactivate into H2SO4 solution. Consequently, the reduced calcium hydroxide content in the concrete makes the concrete non-reactive to sulphate, which in turn increases the resistance of the concrete to sulphate