The depletion of natural resources, coupled with the rising levels of construction and demolition (C&D) waste, highlights the need for sustainable solutions in the construction sector. Current study examines the effects of both unprocessed and processed recycled concrete aggregates (RCA) on the mechanical properties of high-strength concrete (HSC). Study compares the concrete moulded with natural aggregates, unprocessed, and processed RCA treated with 500 revolutions in a Abrasion machine. Further, RCA replaced with natural aggregates at a level of 25% and 50% proportions, and the mechanical properties, including compressive strength, split tensile strength, and flexural strength, were evaluated. The results demonstrate that processed RCA significantly enhances mechanical properties compared to unprocessed. With 25% replacement, the compressive strength of processed RCA touched 48.2 MPa at 28 days, closely approaching the 50.4 MPa achieved by the natural aggregate control mix, whereas unprocessed RCA attained only 46.1 MPa. Both RCA types showed similar split tensile strength, indicating effective interlocking. However, flexural strength tests demonstrated that processed RCA outperformed unprocessed RCA by 31.3%, emphasizing superior bonding and mechanical interlocking in the concrete matrix. Although processed RCA shows improved performance, it does not entirely match the strength of natural aggregates. These findings suggest that while RCA processing techniques can enhance its viability in HSC, further advancements and the use of supplementary materials may be required. The study highlights the potential of processed RCA to contribute to more sustainable construction practices, reducing reliance on natural aggregates and addressing C&D waste management.