Desiccation cracking behavior and its suppression methods in lateritic soil under drying and wetting cycles

Abstract

Abstract In this study, the desiccation cracking behavior of lateritic soil caused by drying and wetting cycles was investigated and effective methods for mitigating crack development were proposed. Direct mixing and spray coating methods based on different additives were used to modify lateritic soil. Cyclic wet–dry tests were performed to analyze the influence of wet–dry cycles on the cracking behavior. Subsequently, uniaxial tensile tests were conducted to examine the strength degradation caused by crack formation and strength enhancement by additives. In addition, the modification mechanisms were revealed using electron microscopy. The results demonstrated that desiccation cracks developed significantly during the drying process, with some cracks closing upon wetting. However, most of the cracks reopened and expanded further during subsequent drying, leading to a steady increase in the crack rate during the wet-dry cycles. When using the direct mixing method, lignocellulose was the most effective additive for enhancing the crack resistance of lateritic soils. The optimal crack resistance was achieved with a lignocellulose content of 0.75%, resulting in an 18.2% increase in tensile strength. Conversely, when employing the spray coating method, PAC was found as the optimal additive, with a desirable concentration of 1.5–6.0%.