Production of soil cement bricks using sludge as a partial substitute

Abstract

Water treatment plants (WTP) produce copious quantities of solid waste in the form of sludge that is deteriorating water resources, agriculture lands and human health. It should be discarded properly but a grave issue is finding ecological solution for its ultimate disposal. This study will provide an idea of incorporating sludge into soil-cement bricks that are used for construction providing dual benefits: reducing amounts of sludge and introducing cheaper bricks. A sample of sludge was analyzed for chemical constituents, plasticity value, particle size and content of organic matter. Sludge bricks incorporating 10 % of waste material by weight were prepared. The quality of sludge bricks was evaluated in terms of mechanical and physical properties (compressive strength test, water absorption test and apparent density test). The obtained results have revealed that waste material is mostly composed of plastic and could be utilized for manufacturing of sludge bricks. The compressive strength and density of bricks reduced with increasing amounts of sludge. However, the compressive strength of the bricks could even meet the standard requirement.

Soil-cement blocks: a sustainable alternative for the reuse of industrial solid waste

“…According to Anjum et al (2017), the addition of sludge from wastewater treatment plants directly affects the increase in water absorption in the block, as it is a plastic solid waste. Because of that, it also affects the cement hydration reactions next to the organic matter present in the sludge and the type of soil used, since the sludge traps large amounts of water; therefore, it lacks an adequate amount of water to complete these reactions.…”

Direct Shear Test of Unsaturated Soil

“…Test samples in triaxial tests are relatively bigger (39.1 mm diameter, 80 mm thickness; 50 mm diameter, 100 mm thickness and 70 mm diameter, 140 mm thicknesses). Thus, determining the matric suction requires much more time; comparatively time associated with shear strength testing of unsaturated soils is significantly reduced from the smaller size of test samples, generally 61.8 mm diameter, 20 mm thickness (Bishop et al, 1960;Bishop et al, 1963;Ali et al, 2017;Anjum et al, 2017).…”