Evaluation of the physical and mechanical properties of concrete with the incorporation of recycled concrete aggregate

The construction industry generates tons of waste annually worldwide, causing a significant impact on the environment. The massive accumulation of construction and demolition waste exacerbates this problem, particularly in countries like Peru where the construction industry is rapidly growing. This research proposes addressing this challenge by substituting natural aggregates in concrete production with recycled concrete aggregates (RCA), treated beforehand. The main objective is to assess the feasibility of using RCA in concrete as a partial substitute for coarse aggregate and to analyze the physical and mechanical properties of concrete incorporating RCA to address its use in the Peruvian context. Within the methodology employed, five types of samples with recycled concrete at proportions of 10%, 20%, 30%, and 40% by weight of coarse aggregate were prepared, and physical and mechanical properties were evaluated at 7, 14, and 28 days. The results showed that the optimal RCA content was 20%, where slump, unit weight, and air content decreased but remained within permissible ranges. Additionally, it was observed that mechanical properties remained stable without significant variations. The compressive strength did not exhibit values lower than 21 MPa compared to the reference concrete. Likewise, the modulus of elasticity, tensile strength, and flexural strength decreased, showing a consistent trend. Consequently, it can be concluded that recycled aggregates are viable as effective substitutes for natural aggregates in the production of sidewalks, slabs, pavements, etc., offering a sustainable and environmentally friendly alternative.