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.

Current development consists of a high-rise building and heavy traffic load demands for soil with good engineering properties. Lateritic soil is commonly treated with Ordinary Portland Cement (OPC) to improve its engineering properties in order to enhance its load bearing capacity. The production of OPC however emits a large amount of carbon dioxide (CO2) into the atmosphere. Geopolymer technology has been explored as an alternative replacement for the OPC. In this research, the unconfined compressive strength (UCS) of a lateritic soil treated with fly ash (FA) based geopolymer up to 40% by weight of the dry soil and activated using combination of sodium silicate (Na₂SiO₃) and sodium hydroxide (NaOH) was investigated by means of unconfined compression test (UCT). The effect of different molarity of NaOH (5-20 M), FA to alkali activator (AA) ratio (1-3) and different curing temperatures to the UCS of treated soil sample are being determined. In general, as the content of FA in the soil increases, the UCS increases more than 100% and almost 400% compared to the untreated soil for room curing temperature and oven curing temperature respectively. Based on the scanning electron microscopy (SEM) result, the molarity of NaOH solution reduces the pores in the treated soil sample. The geopolymerization process combines the soil particle and makes it denser, resulting in higher UCS than the untreated soil sample.