Characteristics of geopolymer using rice straw ash, fly ash and laterite soil as eco-friendly materials

Abstract

This study discusses the utilization of Rice Straw Ash (RSA), Fly Ash (FA) and alkali activator (NaOH) to bind laterite soil (LS). RSA and FA are geopolymer activated with 12M NaOH. Geopolymer mortar strength was tested, where the percentage ratio of RSA/FA/LS was 16.67/41.67/41.67. Flow testing on fresh geopolymer shows that all materials are well bound and segregation does not occur. Specimen were cured with three variations, namely immersed in water, immersed in Na2SO4 and immersed in H2SO4 solution until 28 days to evaluate its durability. The compressive strength and stress-strain relationships are analyzed to study the behaviour of hardened mortar geopolymer. Method of treatment and age of mortar can be effective for compressive strength. The geopolimeryzation show increased strength in the immersion of sulphate solution. The XRF test results confirm that the pozzolanic from RSA can be bound by geopolymers. The results of this reactivity are very promising in terms of the potential reuse of ash in the cementing systems.