EFFECT OF MICRO LIME ON THE ENGINEERING PROPERTIES OF AMBIENT TEMPERATURE-CURED SUGARCANE BAGASSE ASH-BASED GEOPOLYMER CONCRETE

Abstract

significant carbon emissions. Advancing concrete technology places geopolymer concrete as a potential green concrete by completely replacing Ordinary Portland Cement. However, the geopolymerization process is initiated at elevated temperatures, which demands that curing at elevated temperatures be conducted for several hours, limiting its application. Calcium ions in Geopolymer concrete (GPC) allow the formation of Calcium Aluminate Silicate and Calcium Silicate Hydrate gels, allowing ambient temperature curing. To study the effect of micro lime on the engineering properties of ambient temperature-cured sugarcane bagasse ash-based GPC, this research used Sugarcane Bagasse Ash (SCBA) as source material; one part of sodium Hydroxide 16M solution and two parts of sodium silicate were used as the alkaline activator. Crushed stones and river sand were utilized as the coarse and fine aggregates, respectively. A sodium naphthalene formaldehyde (SNF) based superplasticizer was added at 3% of the SCBA. Micro lime was added as an admixture in varying proportions as a percentage weight of SCBA. In the fresh state, it was found that the workability decreased with the increase of micro lime content. The ambient temperature curing of the SCBA-based GPC was achieved at a 1% addition of the micro lime. The SCBA-based GPC's compressive strength increased with the micro lime increase, up to 7%. The ambient temperature cured SCBA-based GPC at 3% had the best water absorption resistance. The SCBA based GPC had no significant weight loss on 2.5% sulfuric acid exposure. The 5 and 7% micro lime mix had no significant change in compressive strength under the condition of sulfuric acid, unlike the 0,1 and 3%. The results from this research contribute to the body of knowledge on ambient temperature-cured SCBA-based geopolymer concrete. It reveals the possibility of expanding the applications of GPC made from the locally available source material, SCBA.