Preparation and Characterization of High Compressive Strength Geopolymeric Monoliths Using Silica Waste

The goal of the present work was investigated development of ET(Environmental Technology) industrial geopolymer materials from mixture Silica Mine Waste(SW) and ground granulated blast furnace slag(GGBFS) and alkali activator solution(sodium silicate) by the Geopolymer Technique at ambient temperature. As for the synthesis of geopolymeric monoliths, four different GGBFS content(10wt%, 20wt%, 30wt%, 40wt%) and three types of GGBFS(GGBFS-1(blaine 4,000cm2/g), GGBFS-2(6,000cm2/g), GGBFS-3(8,000cm2/g)) are investigated to obtain the optimum synthesis condition based on the high compressive strength. The weight ratio between the alkali activator solution and dry mix(SW and GGBFS) were 0.25 and 0.3, respectively. The results showed that geopolymeric monolith containing 30wt% GGBFS exhibits higher compressive strength and increased along with increase of GGBFS blaine. The compressive strengths of GGBFS-1, GGBFS-2 and GGBFS-3 are 66.7MPa, 83.1MPa, 94.1MPa, respectively. Additionally, scanning electron microscope (SEM) techniques are used to characterize the microstructure of the geopolymeric monoliths. SEM observation shows that it is possible to have amorphous aluminosilicate gel and calcite forming simultaneously within monoliths. XRD patterns indicate that geopolymeric monolith is composed of amorphous aluminosilicate phase and calcite and quartz.