Abstract

This study assesses the technical feasibility of replacing portions of the cement in mortar mixes with copper mine tailings, with a particular focus on mechanical strength. Compression, flexural, workability (flow test), and splitting tensile strength tests were conducted with different replacement percentages of cement by copper tailings (10, 20, and 30%). The experimental setup included three study cases: (i) fine aggregates, (ii) coarse aggregates, and (iii) fine aggregates with double the cement/tailings dosage ratio. The results revealed a decrease in mechanical strength as the percentage of mining tailings increased for compressive and tensile strength. However, the compressive and flexural strength increased when the cement-to-water ratio was increased in which case good mechanical results were obtained. In particular, in case (iii), the flexural strength increased by almost 40% when a mixture with 30% of copper tailings was used. Thus, the results obtained here suggest that it is feasible to use copper tailings in the manufacture of mortars, achieving acceptable mechanical strength and promoting a circular economy in copper extraction.