Density, Compressive Strength and Water Absorption Properties of Sand Cement Brick Containing Recycled Concrete Aggregate (RCA) and Crumb Rubber (CR) as Partial Sand Replacement Materials

Commercial construction in Malaysia commonly used natural fine aggregate as the building materials. Concrete production has recently been increased as linear with the economic growth of Malaysia. However, the concrete industry is facing a challenge to find adequate sources of natural fine aggregates and currently considering in utilizing the alternative to substitute fine aggregate with the waste material for concrete production. Thus, a combination of Recycled Concrete Aggregate (RCA) and Crumb Rubber (CR) was used in this research as a partial of sand replacements materials in the sand cement brick. This research aims to study the performance of sand cement brick that contains a combination of RCA and CR as partial sand replacement materials in terms of density, compressive strength and water absorption. A total of 144 brick specimens were prepared and mixed with different percentages of RCA and CR as a partial sand replacement material. The design replacement of RCA was set to 0, 15, 30 and 45%, while CR was 0, 2, 4 and 6. Other than, W/C ratio that was used in this research was 0.6. The tests that were conducted included sieve analysis, density, compressive strength and water absorption tests. The brick was tested on day 28 after the brick was prepared. Based on the result, the percentage of water absorption was increased after incrementing of CR while RCA after 30% of replacement. In addition, the percentage of compressive strength and density was decreased after incrementing of CR while RCA after 30% of replacement. Throughout this research, brick that contained 30% of RCA and 2% of CR showed the optimum mix design where it shows the highest percentage of compressive strength and lowest in water absorption compared to another mix design. It is potentially applicable to the RCA and CR as secondary sources of natural fine aggregate and also can reduce waste of RCA and CR in Malaysia.