The Effect of Copper Tailings Sand on the Workability and Mechanical Properties of Concrete

Abstract

Concrete materials are widely used in engineering projects, with fine aggregates (sand) being a key component currently in short supply. Copper tailings sand, a waste by-product of copper mining, accumulates in large quantities in tailings dams. Recycling and reusing this waste sand is crucial for environmental sustainability. This paper investigated the incorporation of copper tailings sand into concrete as a partial replacement for fine aggregates and evaluated its effects on concrete’s workability and mechanical properties. The experimental results indicate that the addition of copper tailings sand reduced the workability and compressive strength of concrete. Specifically, at a 60% substitution rate, the slump of the concrete was reduced by 15%, and the axial strength was closest to that of ordinary concrete, with a reduction of 2.5%. As the proportion of copper tailings sand increased from 0% to 80%, the average axial strength decreased from 37.3 MPa to 34.9 MPa, and stiffness decreased by approximately 6.43%. A complete stress–strain curve equation was proposed based on fitting relevant parameters, closely aligning with experimental data. Moderately adding tailings sand can help address the issue of large amounts of waste sand accumulating in tailings dams while maintaining acceptable concrete properties.