Evaluation of the Compressive Strength of Concrete Using Bush Gravel as Coarse Aggregates Partially Replaced with Broken Bricks

Abstract

Abstract: Concrete is the most used building material in the construction industry. In recent years, concrete production has become more expensive due to the increase in demand for it, which has led to a rise in the cost of concrete production. This has compelled the construction industry to find alternatives to concrete production. In this study, the compressive strength of concrete is evaluated when bush gravel, as coarse aggregate, is partially replaced with broken bricks which have acceptable properties comparable to a normal concrete. The absolute volume method was used in determining the values of water/cement ratio, aggregate/cement ratio and the relative proportions of aggregates of various sizes. Mix ratio of 1:2:4 and water/cement ratio of 0.45% were used. The compressive strength observed after 7 days was 15.29, 14.39, 14.68, 14.55, 14.22, 13.41 and 10.75N/mm 2, while compressive strength after 14 days was 18.46, 16.12, 15.38, 15.23, 14.87, 14.82 and 13.67N/mm 2,compressive strength after 21 days was 20.45, 19.94, 19.63, 19.41, 19.26, 17.78, and 14.81N/mm2, and finally after 28 days, the compressive strength was 23.63, 21.85, 20.30, 19.29, 18.26, 18.22 and 16.45N/mm2 all for 0, 10, 20, 30, 40, 50, and 60% replacements of broken bricks respectively. These results clearly shows that the compressive strength of concrete increases as the curing ages increases and both bush gravel and broken bricks can be used as coarse aggregates for structural concrete when structural coarse aggregates are hard to find, and where high strength of concrete is not needed.