Incorporation of Waste Glass as an Activator in Class-C Fly Ash/GGBS Based Alkali Activated Material.

In this study, an alkaline activator was synthesized by dissolving waste glass powder (WGP) in NaOH-4M solution to explore its effects on the formation of alkali-activated material (AAM) generated by Class-C fly ash (FA) and ground granulated blast furnace slag (GGBS). The compressive strength, flexure strength, porosity and water absorption were measured, and X-ray diffraction (XRD) and scanning electron microscopy with energy dispersive X-ray (SEM-EDX) were used to study the crystalline phases, hydration mechanism and microstructure of the resulting composites. Results indicated that the composition of alkali solutions and the ratios of FA/GGBS were significant in enhancing the properties of the obtained AAM.

Strength and Microstructure of Class-C Fly Ash and GGBS Blend Geopolymer Activated in NaOH & NaOH + NaSiO.

In this paper, class-C fly ash (FA) and ground granulated blast-furnace slag (GGBS)-based geopolymer activated in NaOH and NaOH + NaSiO was studied regarding setting time, compressive strength, porosity, microstructure, and formation of crystalline phases. When comparing the effects of alkali type on the FA and GGBS geopolymer composites, results revealed that NaOH has a lesser effect in developing strength and denser microstructure than does NaOH + NaSiO since the addition of NaSiO provides the silica source to develop more compact structure. Incorporation of NaSiO reduced the crystallinity and the paste was more amorphous compared to NaOH activated pastes.