Effective utilization of silica fume and waste colemanite in eco-sustainable prepacked geopolymers

Abstract

In this work, the ternary prepacked aggregates geopolymer composites (PAGC) consisting of waste colemanite (WCM), silica fume (SF), and ground granulated blast furnace slag (GBFS) were created with the cement clinker aggregate (CCA). The performance and microstructure of PAGC mixtures were examined in relation to the impacts of WCM concentration and curing temperatures (ambient (23oC), 50oC, and 75oC). WCM, SF, and GBFS were utilized in the production of PAGC as precursors. Sodium silicate (Na2SiO3) and sodium hydroxide (NaOH) were used as activators. Four PAGC mixes were created and cured at ambient (23oC), 50oC, and 75oC for eight hours. Studies were done to determine the influence of WCM content and different curing temperature on the compressive strength, transport properties, flexural strength, sorptivity and dry unit weight properties of PAGC. The heat-resistant characteristics of the resultant blends were also evaluated. The microstructure of the PAGC mixes created during the study was also examined using SEM. The results showed that the mixture M1, which contained 100kg/m3 of WCM and 900kg/m3 of GBFS, had the highest compressive strength of 16.37, 29.90, and 51.67MPa at ambient, 50oC, and 75oC, respectively. Furthermore, the mixture M1 showed strength enhancements of 82.65% and 215.64%, at 50 °C and 75 °C respectively, when compared to the samples cured at ambient. Inclusion of WCM to the PAGC mixtures improved the high temperature resistance at ambient curing. The highest WCM content of ambient cured mixture M4 resulted in a strength improvement of 34.65, 27.19, and strength loss of 11.84% at high temperature of 150oC, 350oC, and 550oC, respectively.