RESPONSE SURFACE MODELLING OF PERFORMANCE OF CONCRETE WITH BAUXITE LATERITE SOIL AND FLY ASH
Keywords:Bauxite laterite soil, Fly ash, Compressive strength, Response surface modelling, Philippines
The study examined the use of waste materials such as fly ash and bauxite laterite soil in concrete to address waste disposal issues and reduce the cost of concrete products. Bauxite laterite soil is a byproduct of aluminum extraction, while fly ash is a byproduct of coal-fired power plants. To produce bauxite laterite concrete, 20% fly ash was utilized as a partial cement substitute, and 10%, 20%, 30%, and 40% bauxite laterite soil was utilized as a fine aggregate substitute. The mechanical properties of bauxite laterite concrete were studied and compared to those of conventional concrete. The test results indicate that a 10 % substitution of bauxite laterite soil is the optimal amount. After 28 days of curing, the mixture achieved a 58% improvement in compressive strength compared to conventional concrete. In addition, bauxite laterite concrete exhibited high early compressive strength and a unit weight decrease of between 6% and 8%. However, as more bauxite laterite soil was incorporated into the mix, the concrete's workability decreased. Moreover, a Response Surface Model was developed to predict the compressive strength of the bauxite laterite concrete. It can be inferred that both bauxite laterite soil and fly ash are viable alternatives to fine aggregates and cement.