This paper elucidated the potential of electron backscatter diffraction analysis for ground granulated blast furnace slag geopolymers at 1000°C heating temperature. The specimen was prepared through the mechanical ground with sandpaper and diamond pad before polished with diamond suspension. By using advanced technique electron backscatter diffraction, the microstructure analysis and elemental distribution were mapped. The details on the crystalline minerals, including gehlenite, mayenite, tobermorite and calcite were easily traced. Moreover, the experimental Kikuchi diffraction patterns were utilized to generate a self-consistent reference for the electron backscatter diffraction pattern matching. From the electron backscatter diffraction, the locally varying crystal orientation in slag geopolymers sample of monoclinic crystal observed in hedenbergite, orthorhombic crystal in tobermorite and hexagonal crystal in calcite at 1000°C heating temperature.

This study explores the influence of alkali activators on the initiation of polymerization reaction of alumino-silicate minerals present in class-F fly ash material. Different types of fly ash aggregates were produced with silicate rich binders (bentonite and metakaolin) and the effect of alkali activators on the strength gain properties were analyzed. A comprehensive examination on its physical and mechanical properties of the various artificial fly ash aggregates has been carried out systematically. A pelletizer machine was fabricated in this study to produce aggregate pellets from fly ash. The efficiency and strength of pellets was improved by mixing fly ash with different binder materials such as ground granulated blast furnace slag (GGBS), metakaolin and bentonite. Further, the activation of fly ash binders was done using sodium hydroxide for improving its binding properties. Concrete mixes were designed and prepared with the different fly ash based aggregates containing different ingredients. Hardened concrete specimens after sufficient curing was tested for assessing the mechanical properties of different types concrete mixes. Test results indicated that fly ash -GGBS aggregates (30S2‒100) with alkali activator at 10M exhibited highest crushing strength containing of 22.81 MPa. Similarly, the concrete mix with 20% fly ash-GGBS based aggregate reported a highest compressive strength of 31.98 MPa. The fly ash based aggregates containing different binders was found to possess adequate engineering properties which can be suggested for moderate construction works.

The effects of supplementary cementitious materials (SCM) on the characteristics and internal structure of synthetic aggregate made from ground granulated blast furnace slag are investigated in this study (GGBS). Due to its high pozzolanic activity, GGBS was shown to be superior to other SCM materials, enhancing both the strength and durability of synthetic aggregate. Because sintering uses a lot of energy and generates a lot of pollutants, using a cold-bonded approach to make low density lightweight aggregates is particularly significant from an economic and environmental standpoint. Thus, the utilisation of ground granulated blast furnace slag (GGBS) as a substitute material in the production of green artificial lightweight aggregate (GLA) using the cold bonding method was discussed in this work. Admixtures of ADVA Cast 203 and Hydrogen Peroxide were utilised to improve the quality of GLA at various molar ratios. The freshly extracted GLA was then evaluated for specific gravity, water absorption, aggregate impact, and aggregate crushing in order to determine the optimal proportion blend. As a result, the overall findings offer great application potential in the development of concrete (GCLA). It has been determined that aggregates with a toughness of 14.6% and a hardness of 15.9% are robust. The compressive strength test found that the GCLA has a high strength lightweight concrete of 37.19 MPa and a density of 1845.74 kg/m3. The porous features developed inside the internal structure of GLA have led to GCLA’s less weight compared to conventional concrete.