EVALUATION OF MICROSTRUCTURE AND COMPRESSIVE STRENGTH PROPERTIES OF BINARY BLEND ALKALINE ACTIVATED MORTAR

Abstract

Alkaline Activated materials have been proven recently to be the way of converting Agricultural, thermal and industrial waste into construction repair materials. This paper evaluates the microstructure and compressive properties of Cassava Peel Ash (CPA) incorporated Metakaolin (MK) based Alkaline Activated Mortar (AAM). Sodium silicate (Na2SiO3) and sodium hydroxide (NaOH) solution were used as an alkaline activator and NaOH in varying concentrations of 6, 9 and 12 M. The mass ratios of sodium silicate to sodium hydroxide (NS: NH) and the binder to fine aggregate (B: A) were fixed to 2.5 and 0.4 respectively. The specimens were subjected to a curing temperature of 60ºC for a duration of 24 hours. The compressive strength of the synthesized AAMs was determined at 3, 7 and 28 days. The use of Scanning Electronic Microscope (SEM) was used to study the microstructure of the mortar. It is demonstrated that 50% of MK replaced CPA of 12m of NaoH achieved the highest compressive strength as much as 47.6 N/mm2 at 28 days curing. The strength and microstructural characteristics of the synthesized AAMs was significantly improved. The study showed that the use of Cassava Peel Ash and Metakaolin in the production of sustainable green geopolymer mortar is a suitable alternative repair material that is feasible both technically and environmentally.