Mechanical performance of eco-friendly cement mortar incorporating aluminum dross under acidic exposure

The incorporation of aluminum dross into cement-based mortars offers potential benefits for environmental sustainability; however, it may adversely affect the mechanical performance of the material. This study integrates experimental testing with statistical analysis to evaluate the influence of aluminum dross on the mechanical properties of mortar specimens exposed to sulfuric acid (pH 1.5). Compressive strength, flexural strength, and mass variation were measured for mortars containing different aluminum dross contents. Following 28 days of water curing, the specimens were immersed in sulfuric acid for periods ranging from 0 to 90 days. The results indicate that exposure to sulfuric acid led to progressive deterioration in all mortar mixtures, with average reductions of 39% in compressive strength after 14 days and about 80% after 90 days. Before acid exposure, increasing aluminum dross content reduced the initial mechanical strength by up to 28% compared with the control mixture. Under prolonged acidic conditions, slag-containing mortars-particularly those incorporating 10% and 15% aluminum dross-exhibited reduced strength loss and enhanced acid resistance compared to slag-free control specimens. Statistical analysis demonstrated strong correlations between mechanical properties, acid exposure duration, and mass loss, whereas the effect of aluminum dross content was less significant. These findings underline both the potential benefits and the practical limitations of using aluminum dross in sustainable cement mortar applications subjected to acidic exposure.