Reusability of concrete sludge in sand brick

Abstract

In this study, bricks manufactured from dried concrete sludge collected from a concrete batching plant were investigated. Five different series of sludge proportioning ratios were studied, which exclusively involved the addition of sludge with ratios 10, 20, 30, 40 and 50 percent of the total weight of the mixture and one without the addition of sludge which served as control. Results of the tests indicated that the sludge proportion was a key factor in determining the brick quality. An increased in the sludge content results in the decrease of bulk density and compressive strength while the water absorption is increased. As result, brick with concrete sludge content of 10 to 30 % wt can be categorized as load bearing bricks class 1 with minimum compressive strength of 7 N/mm2 while other portions can be considered as non-load bearing bricks with minimum compressive strength of 1.4 N/mm2.