Application of rice husk ash in high strength concrete

Rice husk ash waste would cause dangerous environmental problems in soil and air. One of the solutions to overcome the environmental impact of rice husk ash is by processing it into a partial substitute for cement. The purpose of this study was to analyze the compressive strength of high strength concrete. The method used was experimental research by utilizing rice husk ash as a cement substitute in concrete with a percentage of 0%, 5%, 10%, 15%, 20%, and the addition of superplasticizer. The test object was made with a diameter of 10 cm and a height of 20 cm. The test object was treated using clean water. The strength of concrete with rice husk ash as a cement substitute was tested based on absorption and compressive strength of concrete on day 7 and day 28. Thus, the optimum compressive strength was obtained in the variation of 10% rice husk ash as the cement substitution. Based on this study, the highest average compressive strength was found in concrete with a variation of 10% rice husk ash, which was 38.5 MPa at 7 days and 56.2 MPa at 28 days.