Strength performance of sodium hydroxide-activated fly ash, rice straw ash, and laterite soil geopolymer mortar

Abstract

Abstract The geopolymer of fly ash (FA), rice straw ash (RSA) and laterite soil (LS) was prepared. The strength of the geopolymer mortar with the FA/RSA/LS percentage ratio of 41.67/16.67/41.67 was tested. The geopolymer was activated with sodium hydroxide (NaOH). Effect on air curing on compressive strength as well as the optimum mix proportion of geopolymer mortar was investigated. It is possible to achieve compressive strengths of 1.64 N/mm2, 1.72 N/mm2, and 3.22 N/mm2, respectively for the 12 M sodium hydroxide-activated geopolymer mortar after 3, 7 and 28 days of casting when air cured. Results indicated that the increase in the curing period increased the compressive strength.