Experiment on making autoclaved sludge bricks with water- treatment plant sludge

摘要

This is an experiment on making autoclaved sludge fly ash bricks with reference to the technology of making autoclaved fly ash bricks. To probe into the feasibility of making autoclaved fly ash bricks with dewatered sludge, tests and analysis of the compressive strength, flexural strength, freezing resistance, drying shrinkage, carbonation, corrosion of the autoclaved sludge bricks as well as the dilution and solidification of heavy metals during the autoclaving process are carried out. The test results show that the compressive strength decreases with the increase of sludge content, and the flexural strength increases slightly with lime content increased. The freezing resistance, drying shrinkage and carbonation coefficient of autoclaved sludge fly ash bricks meet the quality requirements of fly ash brick MU20. The leaching liquid of the autoclaved sludge fly ash brick is non-corrosive. The heavy metals in sludge can be effectively solidified in autoclaved sludge fly ash brick and the leaching liquid meets the requirement of Class III water standard in China's “Surface Water Environmental Quality Standard” (GB3838-2002).