Thermal and durability characteristics of optimized green concrete developed using slag powder and pond ash

Due to the vast development in the infrastructure section, the production of cement-based concrete is a major driving source for the increased global warming and extensive deployment of natural resources such as river sand. To reduce and mitigate these adverse effects, industrial by-products can be effectively used either in partial or complete levels to replace conventional materials such as cement, river sand, etc without compromising the strength and durability characteristics of concrete. This research work focuses on the experimental investigation of the thermal properties, strength, durability and microstructure analysis of optimized green concrete with pond ash and ground granulated blast-furnace slag (GGBS). The novelty of the proposed work lies in the investigation of the thermal and durability characteristics of sustainable green concrete with GGBS and pond ash as a partial replacement for cement and fine aggregate respectively. An optimum mix ratio obtained from the material characterization of 16 trail mixes was tested for mechanical properties, durability and thermal characterization. Moreover, the microstructure analysis of the optimized mix was performed using Scanning Electron Microscope (SEM) to overview the chemical constituents, bonding of molecules at the interfacial transition zone (ITZ), the effect of elevated temperature, etc Results from the trail mixes revealed that the replacement of 30% GGBS and 20% pond ash increased the compressive strength by 8% at 28 days of curing when compared to the control mix. In addition, a detailed multilinear regression analysis was performed and a new equation was proposed to determine the compressive strength of concrete with GGBS and pond ash. The predictions obtained from the proposed equation showed a good match with the benchmark experiments.