Characterization of automobile effluent treatment plant sludge: Its utilization in construction materials

•Characterization of automobile ETP sludge.•Effect of ETP sludge on the properties of blocks, tiles, bricks studied.•Leaching test revealed that concentration of leached metals is quite low.•ETP sludge up to 35% can be utilized for making construction materials. In this study, the characterization and influence of automobile effluent treatment plant sludge on the properties of cement–sludge binder, paver blocks and flooring tiles is discussed. The engineering properties of burnt clay bricks prepared by partial replacement of soil with automobile sludge at 900°C and 1000°C were evaluated. The results of leaching studies, conducted for tiles/paver blocks samples using Toxicity Characteristic Leaching Procedure, revealed that the concentration of leached metals is quite low than the limits specified in Indian Standard. These results amply demonstrated that automobile sludge up to 35% can be utilized for making building components.