Incorporating Construction Waste into Concrete Matrix: An Approach to Environmental Sustainability

Abstract

This study investigates the mechanical performance of concrete incorporating construction and demolition waste materials as partial replacements for conventional fine and coarse aggregates. Both mixes were designed at a 1:2:4 ratio with a w/c of 0.6 (BS EN 12390-3:2019 and BS EN 12390-5:2019). A total concrete volume of 0.09075 m³ was prepared for laboratory testing.

The results showed that the compressive strength of conventional concrete increased from 10.40 N/mm² at 7 days to 15.31 N/mm² at 28 days, while the corresponding values for CWICM were 6.22 N/mm² and 10.00 N/mm², respectively. Similarly, the flexural strength of CC improved from 2.56 N/mm² to 4.20 N/mm², whereas CWICM recorded 1.98 N/mm² to 2.56 N/mm² across the same period.

Regression analysis revealed that cube age and maximum crushing load are statistically significant predictors of compressive strength (p < 0.05), with cube age showing the highest standardized coefficient (β = 0.941). For flexural strength, cube age also exhibited the strongest influence (p = 0.008), while density and compressive strength showed moderate but statistically insignificant effects.

This research demonstrates the potential of reusing construction and demolition wastes as sustainable alternatives in concrete production.