Eco-Friendly Concrete Using Recycled Aggregates from Excavation, Construction and Demolition Waste

The study focuses on the attempt to produce structural concrete, class C25/30 with exposure class XC3, using recycled aggregates derived from Excavation, Construction and Demolition Waste (ECDW) management. All the necessary properties of the recycled aggregates used were determined and four concrete mix compositions were made with recycled aggregate percentages ranging from 25% to 100%, while two more mix compositions were made with natural aggregates (NAs) to compare the results. A total of 78 cubic specimens, 13 from each mix, were obtained and their compressive strength, dynamic modulus of elasticity, rebound number, maximum deformation and maximum mass loss due to evaporation were determined at ages of 3, 7, 14, 28 and 90 days. The results show that 25–50% replacement with mixed recycled aggregates can satisfy the C25/30 strength class, whereas 100% replacement leads to significant strength and stiffness reductions. Overall, the study demonstrates that structural-grade recycled aggregate concrete is feasible up to moderate replacement levels, provided that the high water absorption and increased deformability associated with recycled aggregates are explicitly accounted for in mix design, curing and serviceability checks.