Utilization of Cement Incorporated with Water Treatment Sludge

This study investigated the use of water treatment sludge to replace cement in the production of paving tiles for external use. The study utilized sludge-cement replacement percentages of 10%, 20%, 30%, 40% and 50%. Produced tiles were tested for water absorption and breaking (bending) strength. Leaching of sludge metals from tiles was assessed using TCLP. The study showed that all produced tiles exhibited a water absorption ratio of around 10%. The study concluded that produced tiles, except for 50% sludge-cement replacement, comply with the breaking strength requirements of 2.8 MPa for tiles for external use. The TCLP results indicated that metal leaching from tiles is negligible.