The water treatment plants are industrial units used in large scale in the treatment of raw fresh water for human consumption. However, the process of raw water treatment generates large volume of sludge that needs to be discarded. In Brazil this sludge has been disposed mainly on water resources closer, resulting in environmental, economic and social problems. In this work, a study was done to evaluate the influence of the addition of sludge of water treatment plant (WTP) on the technological properties of soil-cement bricks for use in civil construction. The raw materials used were soil, WTP sludge, and Portland cement. Cylindrical pieces containing up to 5 wt.% of WTP sludge in partial replacement of soil were prepared by uniaxial pressing and cured in a humid chamber for 28 days. The soil-cement bricks were characterized in terms of water absorption, bulk density, and compressive strength. Microstructural analysis of the cured bricks was monitored by confocal microscopy and X-ray diffraction. The results indicated that the incorporation of WTP sludge directly influence the technological properties of soil-cement bricks. Moreover, the WTP sludge studied can be incorporated into soil-cement brick in an amount of up to 1.25 wt.% as partial replacement of natural soil.
WTP sludge; soil-cement brick; properties; recycling
