Optimum Proportion Of Portland Cement, Fly Ash, And Expanded Polystyrene For Maximum Compressive Strength

     Due to the rapid increase in population and urbanization, the demand for cheaper construction materials have also increased. Incorporating recycled materials in construction is a great way of reducing its cost. In this study, lightweight concrete was formed using recycled expanded polystyrene· (EPS) beads, fly ash and cement. EPS was used as replacement for natural aggregates. EPS content of 50%, 65%, and 80% of the total volume were tested. Fly ash was also used as partial replacement for cernent, Fly ash replaced 20%, 40%, and 60% of the cement by volume. Water-binder ratios of 0.4 and 0.6 were used. The result of the compressive strength test was analyzed using multiple regression analysis, and a regression equation was constructed. The regression equation can predict the compressive strength of the concrete mixture based on the values of EPS content, fly ash content, and water-binder ratio. Based on tl1e results of the compressive strength test and regression equation, the mixture with 50o/o EPS content, 20% fly ash content and 0.4 water-binder ratio gives the optimum compressive strength. Based on the measured density of the samples, ranging from 338.714 kg/m3 to 1297.797 kg/m3, the concrete mixtures can be classified as lightweight concrete.