Partial Replacement of Natural Coarse Aggregates by Recycled Coarse Aggregates

Concrete is a ubiquitous material in the construction industry, and its demand is escalating rapidly due to increasing urbanization. The subsequent rise in new building and infrastructure projects has led to a surge in demand for natural aggregates, resulting in excessive quarrying and depletion of natural resources. Concurrently, the demolition of existing structures generates vast amounts of construction and demolition waste, which are typically discarded in landfills. This project investigates the feasibility of replacing natural coarse aggregates (NCA) with recycled coarse aggregates (RCA) derived from demolished concrete in concrete production. The study evaluates the physical and mechanical properties of RCA, including water absorption, density, and compressive strength, compared to NCA. Various concrete mixes with partial and full replacement of NCA by RCA were prepared and tested to assess workability, strength, and durability. This not only requires substantial land areas, which are becoming increasingly scarce, but also poses significant environmental concerns. A viable solution to these dual challenges lies in recycling and reusing demolished concrete as aggregates in new concrete. The project also considers economic factors, such as the cost-effectiveness of RCA in regions with limited access to natural aggregates, and proposes guidelines for its adoption in local construction standards. This project investigates the feasibility of utilizing demolished concrete as a coarse aggregate, exploring its potential as a partial replacement for natural aggregates. The study examines the effects of replacing 0% to 40% of coarse aggregates with demolished concrete, assessing its suitability for use in new concrete applications.