Evaluating slate waste-laterite mixtures for low-volume road base layers

This paper explores the viability of a blend containing crushed slate rock waste and lateritic clayey soil. The geotechnical properties of the base, subbase and regularised subgrade of an experimental low-volume road in Brazil were investigated through laboratory experiments, such as mechanical analysis using resilient modulus and permanent deformation tests. Additionally, numerical simulations were conducted using the mechanistic-empirical MeDiNa software to evaluate rutting and cracked area for comparison analysis between the performance of the soil-slate waste mixture and some conventional base aggregates. Despite high plasticity, lateritic soils combined with crushed slate formed effective mixtures for efficient compaction. The slate-laterite mixture performed similarly to conventional materials in fatigue and rutting simulations. This mixture also exhibited lower permanent deformation compared to others. This outcome has been consistently confirmed in the experimental pavement section over the three years since its construction. The study demonstrates the potential of using slate waste for sustainable pavements.