This study investigates the feasibility of incorporating shredded e-plastic waste as a partial replacement for coarse aggregates in unreinforced concrete such as concrete blocks. Cubes were produced with varying e-waste contents (0%, 10%, 15%, 20%, 25%, 30%) and tested for workability, density, compressive strength, thermal conductivity, water absorption, and dynamic modulus of elasticity. Results showed that increasing e-waste generally enhanced workability and thermal insulation while reducing density and stiffness. The 15% replacement mix demonstrated the most consistent overall performance, combining reliable mechanical strength with improved thermal resistance and reduced water absorption. At 30% replacement, significant weight reduction and insulation gains were observed, although structural integrity declined, making it more suitable for nonload-bearing or thermally focused applications. These findings highlight the potential of 15% e-waste replacement as an optimal solution for sustainable concrete, balancing strength, durability, and energy efficiency.