Utilisation of industrial wastes in fired clay bricks

The stockpile issue of industrial wastes (glass wastes, industrial ash and RCF sand), the energy crisis, high building energy consumption and the related problem of CO2 emissions, and rising expenditures on the household alerted the exploration of innovative recycling strategies. This research aims to develop a strategy for translating industrial wastes into manufacturing fired clay bricks to lower energy costs and minimise CO2 emissions effectively. Physicochemical tests, including compressive strength, water absorption, initial water absorption, X-ray fluorescence (XRF) analysis, SEM analysis, X-ray diffraction (XRD) analysis, 3D-CT scanning and salt resistance tests were conducted to evaluate the physical, mechanical, environmental, durability and morphological characteristics of the bricks. The thermal performance-related properties, including the thermal conductivity, the calorific value, specific heat capacity, emissivity and reflectivity, were investigated. Additionally, in-depth heavy metal leaching investigations were undertaken to assess the environmental impact. The results demonstrated that novel bricks produced from wastes require less firing temperature (15 WGD brick - 5–10 % reduction) and improved thermal performance (WGD brick up to 10 % lower; IWA brick up to 40% lower) while satisfying the other compliance requirements based on national standards. Theoretical firing process energy consumption and the post-application energy (software simulation: Energyplus) results indicated that waste-added bricks required less energy to fire the bricks (average 21% energy savings), as well as less post-application energy (maximum 5% reductions), a reduction in corresponding CO2 emissions (a maximum reduction of 2.07 tonnes per year) and at least 6% economise on utility bills. Ultimately, this study provides a viable solution to the problem of waste accumulation, environmental issues, financial burden and raw material shortages by blending wastes into bricks.