Influence of Reuse of Drinking Water Treatment Plants Sludge in Concrete

This investigation addresses the effect of sludge from water treatment plants as partially replacing cement on the mechanical properties. Various mixtures of sludge powder (SL) after heated treatment at 200℃, 300℃, and 500 ℃ are produced by partially replacing cement with 0%, 5%, 10%, 15%, 20%, and 25 wt%. SL after heated treatment at 200℃ with 0%, 5%, 10%, 15%, 20%, and 25 wt% was replaced with 10% liquid sodium silicate. The program includes the substitution of cement with 5% un-hydrated lime and 10% silica fume at sludge powder after heated treatment at 200℃ with 0%, 5%, 10%, 15%, 20%, and 25 wt%. A series of laboratory tests were performed to investigate the mechanization of strength development which included compressive strength, splitting tensile, flexural strength, SEM, EDX, and mapping. Generally, the results showed that using 5%, 10% sludge in concrete increased the strength and then decreased at 15-25% of sludge. The use of silica fume improved the strength the most and also increase heated treatment of Sludge increased the strength.