Synergistic effect of rice husk, glass and marble sludges on the engineering characteristics of eco-friendly bricks

Due to rapid population growth and industrialization, the generation of different industrial and agricultural wastes has surged in the past few decades. In this study, burnt clay bricks are prepared to investigate the synergistic and individual effect of glass sludge (GS), marble sludge (MS), and rice husk (RH) on the physical, mechanical, durability, and thermal properties of brick samples. Results show that the addition of waste materials (GS, MS, and RH) reduces the shrinkage, weight per unit area, and thermal conductivity of brick samples. All the brick samples incorporating different waste materials show efflorescence much lower than 10%. Furthermore, no brick sample faced any cracking even after 50 freeze-thaw cycles. The mass loss of brick samples incorporating 25% of GS is observed lower than the specified limit of ASTM C67 and are classified as freeze-thaw resistant brick samples. All the brick samples incorporating different waste materials satisfy the minimum compressive strength and modulus of rupture requirements for building bricks and can be used in a moderate weather-resistant environment, leading to sustainable masonry construction. Furthermore, all the brick samples show leaching toxicity values much lower than the specified limits of the Environmental Protection Agency. The scanning electron microscopic images also support the results of porosity and water absorption of brick samples observed in this study. Based on the results, all the combinations of waste materials considered in this study for making brick samples can be used for masonry construction leading towards landfill reduction and the production of eco-friendly bricks.