The recycling of demolition roof tile waste as a resource in the manufacturing of fired bricks: A scale-up to the industry

Abstract

This study illustrates the utilization of roof tile waste as a resource in the manufacturing of fired bricks. Although commonly referred to as demolition waste, it is technically classified as construction and demolition waste (C&D). This demolition waste was used as a partial replacement of two soils (alluvial and laterite soil) at three firing temperatures that were considered economical (700, 850, and 900 °C). The waste considered was obtained from roof tiles previously fired at a low temperature below 800 °C, thus containing residual carbonates and clay minerals. The increased waste input resulted in higher firing shrinkage, bulk density, and water absorption while decreasing loss on ignition. An increase in firing temperature led to higher firing shrinkage, loss on ignition, and bulk density, but lower water absorption. The bricks met both Indian and ASTM standards for 2nd and 3rd class by adding 20–35 wt% of roof tile waste and firing at 850–900 °C in laboratory and industrial settings. The minimum acceptable quality for the produced bricks was achieved with an addition of 35 wt% waste, resulting in a water absorption of approximately 19% and a compressive strength ranging from 6 to 9 MPa. The study suggests that incorporating waste from demolished roof tiles into the production of burned bricks can be advantageous. It can partially replace the need for soils, reduce natural resource usage, lower energy consumption during production, and decrease the carbon footprint.