Compressive Strength of Fly Ash-based Geopolymer Mortar Cured with Electric Oven

Abstract

This research paid attention on the determination of the optimum condition (in terms of both temperature and curing period) for curing via electric oven of fly ash-based geopolymer mortars. The aim was to achieve the highest possible compressive strength at minimum energy consumption; environmental friendliness was also of concern. The study was divided into two parts. The first part was to study the influences of the fly ash-to-activator (FA/AS) ratio of 2.0 to 2.5 and the mass ratio of Na2SiO3-to-NaOH (NS/NH) of 0.5 and 1.0. The second part was to study the influence of the curing temperature (55ºC, 65ºC, 75ºC and 85ºC) and curing period (24, 48 and 72 hours). The optimum points were noted to be the use  of the curing temperature of 65ºC for 24 hours and the mass ratio of Na2SiO3-to-NaOH (NS/NH) of 0.5; or the use of the curing temperature of 75ºC for 24 hours and the mass ratio of Na2SiO3-to-NaOH (NS/NH) of 1.0.