Effect of Strength and Durability of Sand Cement Brick Containing Recycled Concrete Aggregate and Cold Bottom Ash

The market price of brick has risen sharply due to the insufficient brick supply. Therefore, implementing RCA as one of the alternative materials for sand replacement is significant. The consumption of natural aggregate (NA) can be reduced by using the RCA. It is a good step to utilize recycled concrete to minimize the problem of excess waste materials. The results of using RCA and CBA as sand replacements contribute to better performance in compressive strength as compared to the normal brick. The density of the brick was also reduced by 4.95% as the RCA and CBA took place in the brick. Besides that, the water absorption was decreased when incorporating RCA and CBA in the cement brick due to less free water in the mix and fewer voids.

This study aims to ascertain the performance, strength, and durability characteristics of sand cement bricks incorporated with RCA and CBA as partial replacements for sand.

Percentages of 1.5%, 3.0%, 4.5%, and 6.0% of CBA and 15%, 30%, 45%, and 60% of RCA were chosen for partial sand replacement. The brick had dimensions of 215 mm in length, 65 mm in depth and 105 mm in width. Density, compressive force, and water absorption tests were undertaken after each of the three varied ratios of water to cement (1:5, 1:6, and 1:7).

The finding indicates that with the optimum RCA and CBA replacement and the correct water to cement ratio, the performance of the new brick is better than the normal brick.

The optimum sand-to-cement ratio is 1:6, according to the overall results of selecting the optimal sand-to-cement ratio by density, compressive strength, and water absorption test. However, the result for the density value shows that the average brick density is inferior to the control brick. For all of the sample bricks, the compressive strength was best at a sand cement ratio of 1:6. However, as each of the samples complies with the British Standard criterion of less or equal to 15% absorption, it was determined that the sand cement brick's capacity for water absorption was sufficient.