kaolin-Rice husk ash geopolymer activated by sodium hydroxide

Abstract

This research studied the improvement of Bangkok clay using kaolin - rice husk ash activated by sodium hydroxide. Kaolin (KA) was thoroughly mixed with rice husk ash (RA) in the proportion of KA: RA 90:10, 80:20, 70:30, 60:40 and 50:50.  The mixture was then activated by sodium hydroxide solution of 8 molar concentrations at the optimum moisture content. The maximum unconfined compressive strength (q_u) was obtained from sample with KA: RA 70:30 which was used as soil stabilizing agent. The kaolin samples were treated by KA-RA geopolymer replacement of 10, 20, 30, 40, and 50% by weight of dry soil. The samples were cured at 25, 70, and 100°c for 7, 14, 28, 60 and 120 days. Engineering properties were tested including unconfined compressive