<p>Recycled Concrete Aggregates (RCA) are primarily sourced from the demolition of concrete structures, while steel slag is a by-product generated during the steelmaking process. Utilizing waste materials or by-products as aggregates in pavement construction can mitigate the accumulation of waste and environmental pollution while also lowering construction costs. Therefore, the main objective of the present study was to investigate the mechanical properties of asphalt mixtures with RCA and steel slag. The mechanical performance of the bituminous concrete mixes containing three different types of aggregate (steel slag, RCA, natural aggregate) was evaluated in terms of rutting resistance (Hamburg wheel tracking test), cracking resistance (indirect tensile strength, CT_index, and semicircular bending test), stiffness properties (resilient modulus), raveling resistance (cantabro particle loss test) and water susceptibility, and their comparison was made with the traditional mix containing natural aggregates. Subsequently, the asphalt pavements incorporating the aforementioned asphalt mixes as the surface layer thicknesses were designed using IITPAVE software. Asphalt mix containing coarse steel slag and fine RCA emerged as the best performing mix, while asphalt mix comprising coarse RCA and fine natural aggregate emerged as the worst performing mix. Asphalt Mix comprising coarse steel slag and fine RCA was found to be more economical than conventional mix.</p>