This study investigates the utilisation of concrete waste as partial substitute for fine aggregates at different ratios (R.M = 10%, 20%, 30%, 40%, 50%) to enhance the sustainable use of construction and demolition waste (CDW) and appraising their potential use in concrete compositions. In this study, concrete samples were tested for compression, split tensile, and flexure strength at 7, 14, and 28 days to evaluate the performance of the modified mix and compared with conventional concrete mix. Results of the study show that the utilisation of concrete waste as a substitute for fine aggregate up to 30% showed significant improvement in all tested parameter. Compression strength was increased from 29.17 to 39.45 N/mm2, respectively, compared with conventional concrete as shown while split tensile was increased from 3.44 to 4.06 N/mm2 and flexure strength was increased from 3.81 to 4.34 N/mm2 compared with conventional concrete at 28 days. One of the key benefits to the use of recycled materials in construction is that it directly tackles the issue of environmental pollution by reducing landfill space and by conserving natural resources. This alone adds substantial environmental benefit but also enhances the economic value of the concrete structures at the same time. This high-value application for recycled aggregates is a sustainably sound and economically viable option to safeguard the environment.