Recycled Coarse Aggregate Evlauation of its Strength and Durability

Compressive strength tests, a significant decline in strength was recorded. Specifically, 7-day compressive strength decreased by 3.2%, 10.6%, and 15.2% for 20%, 30%, and 40% RCA, respectively. Similarly, 28-day compressive strength decreased by 1.3%, 3.7%, and 15.3% for the same RCA levels. Durability assessments indicated a rise in water permeability, with penetration depth increasing by 0.7 mm, 2.0 mm, and 3.9 mm at 20%, 30%, and 40% RCA replacement, respectively. This suggests a direct correlation between RCA content and concrete porosity. Resistance to acidic and sulfate environments declined with higher RCA content, though moderate durability was observed up to 40% RCA. Moreover, chloride ion permeability increased substantially, with a 271.9% rise at 40% RCA, highlighting potential long-term durability concerns. Overall, the study concludes that RCA replacement up to 30% is optimal for M60 grade concrete, balancing sustainability with acceptable mechanical and durability properties.