EXPERIMENTAL PERFORMANCE OF RECYCLED AGGREGATE CONCRETE IN BANGLADESH CONTEXT

Abstract

Due to the deterioration of existing structures and the replacement of numerous low-rise buildings with comparatively high-rise ones, the amount of demolished concrete in Bangladesh is increasing.  One of the major challenges of our present society is to construct environmental friendly sustainable structures with low-cost technology. Reusing concrete in the form of aggregate would lead to environmental and economical benefits. The research covers experimental work on Particle size distribution by sieve analysis, Fineness modulus, Specific Gravity, Water absorption, Bulk density, and percent void of recycled coarse aggregate. The goal of this study is to measure the compressive strength of recycled aggregates as a substitute for coarse aggregate. For this reason, several important experiments like a) slump test of concrete, b) compressive strength of cylinder concrete specimen are performed. Here, brick aggregates are used as coarse aggregate, the water-cement ratio (0.4) is kept the same, and 30%, 50%, and 70% natural aggregate are replaced by the same percentage of recycled aggregate without any admixture. The result shows that the compressive strength of recycled aggregate concrete (RAC) with 30% replacement of natural aggregate by recycled aggregate is near to the compressive strength of natural aggregate concrete (NAC). It is found that the specific gravity and bulk density of Recycled Concrete Aggregate (RCA) are 2.07 and 1163-1245 kg/m³ respectively which is significantly smaller than Natural Aggregate (NA). Recycled concrete aggregate (RCA) is discovered to have a larger percentage of pore volume and water absorption capacity than natural aggregate (NA), measuring around 13% and 36% respectively. The aggregate properties used in this research are in an acceptable range compared to other researchers.