Thermal performance evaluation of eco-friendly bricks incorporating waste glass sludge

Approximately, 0.3 million tons of waste glass sludge (WGS), a by-product of plate glass manufacturing is being landfilled or discarded every year around the globe. Previously, mechanical and durability properties of burnt clay bricks incorporating WGS were reported by authors. The focus of this study is to explore the thermal properties of industrially manufactured burnt clay bricks incorporating WGS. For this purpose, WGS was obtained from a local glass cutting and polishing industry. Burnt clay bricks incorporating different dosages of WGS (i.e, 5%, 10%, 15%, 20% and 25% by weight of clay) were prepared in an industrial kiln and were studied for different physico-mechanical and thermal properties. It was observed that dense brick specimens can be manufactured by using WGS in replacement of clay. Increase in compressive strength of clay bricks was observed after addition of WGS. Burnt clay bricks incorporating 25% WGS showed 37% increase in compressive strength. Reduction in apparent porosity and water absorption was also observed with increasing content of WGS in brick specimens. Microscopic images also showed dense and homogenous structure with reduced porosity after adding WGS in brick specimens, which increased the thermal conductivity of burnt clay bricks incorporating WGS. Control brick specimens showed thermal conductivity of 0.53 W/mK, which increased to 0.59 W/mK after incorporating 25% WGS in brick specimens. However, results were observed within the thermal conductivity range (i.e., 0.4–0.7 W/mK) of traditional burnt clay bricks for masonry construction. Based on this study, utilization of WGS (up to 25%) in the production of burnt clay bricks can be helpful in reducing the landfill and associated environmental problems of WGS. Moreover, burnt clay bricks with improved properties can be manufactured on industrial scale leading towards sustainable and cleaner production.