Many industrial wastes can be utilized in construction, especially in concrete manufacturing. Disposing of these wastes represents a significant loss of materials that could serve as cost-effective alternatives to natural raw materials, alongside the environmental benefits to communities from reusing brick factory waste. In this study, waste red brick from brick factories with fineness modulus of 1.82 was used as a replacement for fine aggregate with fineness modulus of 3.1. Concrete mixes containing red brick were prepared at replacement ratios from 10% to 50% as a partial substitute for natural river sand. The resulting mechanical properties of the mixes were tested, along with an examination of the impact of red brick on durability through absorption. The results showed that replacing fine aggregates with recycled red brick improves the mechanical properties and durability up to a rate of 30%, with 20% being considered the optimal replacement ratio. This is to benefit from the use of recycled red brick aggregate environmentally and economically. However, higher replacement ratios 40%, 45% and 50% led to reductions in strength. These results suggest that crushed red brick can be safely utilized at moderate replacement levels without significant performance trade-offs. Overall, the research underscores the environmental and economic advantages of incorporating recycled crushed red brick into concrete. This practice contributes to sustainability by reducing waste, conserving natural resources, and mitigating the environmental footprint of construction activities.