STRENGTHENING MORTAR BY USING A TERNARY GEOPOLYMER BINDER MADE OF CASSAVA PEEL ASH, METAKAOLIN, AND RICE HUSK ASH

Abstract

An alternative new ternary geopolymer mortar was developed to resolve a traditional mortar problem which exhibits several disadvantages, including poor strengths and surface microcracks and the CO2 air pollution. The ternary binder was produced using Cassava peel ash (CPA), Metakaolin (MK), and Rice husk ash (RHA) activated with an alkaline mixture of sodium silicate (Na2SiO3) and 9 M NaOH in a mass ratio of 2.5. Five different mix proportions of CPA, MK, and RHA were used to fabricate the ternary geopolymer mortars (TGPM‘s). The water-to-binder ratio was 0.35. The mortars were heat cured for 24 h at 60℃ and then aged under room temperature. Mortar flow and compressive strength was tested. The results showed that the sample C70M20R10, which contained 70% CPA, 20% MK, and 10% RHA, exhibited high compressive strength (50.02 N/mm2 and 54.74 N/mm2 ) without any crack at 28 days and 56 days respectively, after being cured for 24 hours at 60C; however, the C90M07R03 mortar with optimal strength of 55.32 N/mm2 and 58.93N/mm2 for 28 days and 56 days respectively, showed some surface cracks. This ternary binder will be useful from an environmental viewpoint, as it reduces the waste disposed in landfills and helps prevent global warming. Production of new geopolymer binder of mortar as alternative to traditional cement binder with high early and normal strength from low cost waste materials and earth explored materials, less potential of cracking, less energy consumption need and low carbon dioxide emission.