Effect of Na2SiO3/NaOH ratio on compressive strength of lateritic soil mixed with bagasse ash geopolymer

Abstract

This paper investigated the effect of Na2SiO3/NaOH ratio on compressive strength of lateritic soil-bagasse ash geopolymer. Lateritic soil was obtained from Sikhio District, Nakhon Ratchasima. Bagasse ash is a waste from the burning of sugarcane for electricity The lateritic soil to binder ratio was fixed at 85/15. The alkaline activator was composed of sodium silicate solution (Na2SiO3) and sodium hydroxide solution (NaOH) at concentration of 5 M. The Na2SiO3/NaOH ratios were 80/20, 70/30 and 50/50. The compressive strength of lateritic soil-bagasse ash geopolymer samples was evaluated at curing time of 7, 14, 28 and 60 days. It can be seen that the compressive strength of lateritic soil mixed with bagasse ash geopolymer increases as the Na2SiO3/NaOH ratio and curing time increase. The maximum compressive strength of lateritic soil-bagasse ash geopolymer was found at the Na2SiO3/NaOH ratio of 80/20 and curing time of 60 days, which gave maximum compressive strength of 9.84 MPa.