Rice husk ash and spent diatomaceous earth as a source of silica to fabricate a geopolymeric binary binder

Results show that it was feasible to utilize RHA and SDE as a source of silica for geopolymerization. The use of these alternative silica sources delayed the initial and final setting time at 60 °C of a FA/MK-based binary alkali activated geopolymer system. Regardless of the source of silica used, the mechanical strength of the resulting geopolymer binders did not show a significant change over time. The FA/MK-SN system exhibited a final compressive strength of 75 MPa at 360 days, and at the same age FA/MK-DN and FA/MK-RN both reached final compressive strength values of 38 MPa.