Feasibility of using recycled aggregates in high-strength concrete for sustainable construction

The growing demand for construction materials has significantly impacted natural resources, leading to the exploration of alternative, sustainable materials in concrete production. Recycled aggregates (RAs), derived from construction and demolition waste, have emerged as a potential solution to reduce the environmental impact of concrete production. This research investigates the feasibility of using recycled aggregates in high-strength concrete (HSC) to promote sustainable construction practices. The properties of recycled aggregates, such as mechanical strength, durability, and workability, are critical factors influencing their suitability for HSC applications. In this research, different mixes of recycled aggregates were tested and compared with conventional concrete, using various strength grades ranging from 40 MPa to 80 MPa. The results reveal that recycled aggregates can be incorporated into high-strength concrete with an acceptable reduction in strength, but only when specific treatment methods are applied to the aggregates. Notably, the compressive strength of HSC with recycled aggregates was found to be lower than that of conventional concrete, but the use of enhanced methods like improved aggregate washing and pre-treatment with admixtures showed promising results. Furthermore, the environmental benefits of using recycled aggregates, including a reduction in carbon footprint and waste reduction, were quantified. This research concludes that while the use of recycled aggregates in high-strength concrete is feasible, further optimization of aggregate processing methods is needed to enhance its strength and durability for widespread construction applications. The integration of recycled aggregates in HSC can thus contribute significantly to sustainable construction practices, providing a viable alternative to traditional concrete materials.