Compressive and Flexural Strengths of Biomass Ash Geopolymer Mortar

Abstract

This research studied the unit weight and compressive strength of biomass ash geopolymer mortar. Biomass ash is a byproduct of a power plant in Songkhla province. This research used the sand to biomass ash to Portland cement ratios of 50:50:0, 50:45:5, 50:40:10, 500:35:15, 50:30:20, 50:25:25 and 50:20:30, sodium silicate (Na2SiO3) to sodium hydroxide (NaOH) ratio of 70:30, and NaOH concentration of 8 molar. The unit weight and compressive strength of biomass ash geopolymer mortar sample were investigated at curing time of 7 days. The test results showed that the unit weight of biomass ash geopolymer mortar increased as cement content increased. The maximum compressive strength of the biomass ash geopolymer mortar sample was 340 ksc at the sand to biomass ash to Portland cement ratios of 50:25:25.