This document studies using e-waste as a partial replacement for coarse aggregate in concrete. E-waste is a growing environmental issue as electronic products have shorter lifecycles. The study mixes concrete with 0%, 5%, 10%, 15%, 20%, and 25% replacement of coarse aggregate with crushed e-waste. It tests the compressive, splitting tensile, and flexural strengths of the concrete mixtures at various ages when cured in normal water and sea water. The results showed the compressive strength was highest with a 10% replacement of coarse aggregate with e-waste. Using e-waste in concrete provides an environmentally-friendly way to dispose of e-waste while producing concrete with comparable or improved mechanical properties.