Optimizing Waste Glass Powder Content in the Development of Sustainable Concrete for High-Temperature Resistance

The recent globalisation trend and infrastructure development have resulted in large-scale constructions leading to the generation of huge amounts of waste. The resource materials and the construction waste, if judiciously used, can be a step forward in sustainable development. Glass waste is one such product generated all over the world that can prove to be a feasible and environment-friendly solution by incorporating it into concrete. The current study aims to establish an optimum replacement quantity for fine aggregates with waste Glass Powder (WGP). The slag replaced fine aggregates by volume at 5, 10 and 15% to prepare WGP-concrete. Concrete samples cured for 28 days’ strength were initially heated to temperatures of 300 °C, 500 °C, and 800 °C at the rate of 10 °C/min. The heated WGP-concrete specimens are air-cooled to ambient temperature and tested for their residual compressive strength. Subsequently, the samples are tested to evaluate the apparent change in weight, dynamic elasticity modulus, compressive strength, split-tensile strength, flexural strength and relevant non-destructive test parameters. Scanning Electron Microscope imaging for both control and heat-treated specimens was conducted to study their microstructure. The results indicate an increase in compressive strength, flexural strength and split tensile strength initially up to 300 °C. However, these properties tend to decrease at higher temperatures. Heating up to 600 °C leads to minor changes in the compressive strength values for the control mix, and 5% and 10% WGP-replaced concrete; however, a strength drop of 29% is obtained for 15% WGP-replaced concrete. Thus, the use of the appropriate amount of WGP in concrete considering high-temperature effects can help in the sustainable construction of Reinforced Concrete structures.