Organo-modified reservoir sludge as fine aggregates in cement mortars

In Taiwan, a considerable amount of reservoir sludge is being increasingly difficult to dispose of in landfills and creates serious disposal problems. Attempts have been made to study the feasibility of using reservoir sludge as a substitute for a portion of fine aggregates in cement mortars. Reservoir sludge in Taiwan mainly composed of smectite clay is first organo-modified by a cationic-exchange reaction. The compressive strengths and permeability ratios of cement mortars with various percentages of organo-modified reservoir sludge (OMRS) particles were measured and then compared to those of plain cement mortars. The experimental results indicate that it could be possible to replace up to 30% by weight of fine aggregates by OMRS particles in a cement mortar for normal practice. Meanwhile, OMRS particles can be used in controlled low-strength materials (CLSM) if their replacement percentage for fine aggregates is higher than 80%. Also, excellent waterproof of cement mortars is achieved when the percentage of OMRS particles is within the range of 5–50%.