Experimental investigation and modelling of the tensile strength and soil water characteristics of a low-plastic clay

The tensile strength and soil water characteristics of unsaturated soils plays a critical role as a fundamental property in various road engineering projects. The purpose of this study is mainly to investigate the tensile strength and soil water characteristics of compacted and desiccated specimens with varying water contents with under the dry density of 1.5, 1.6, and 1.7 g/cm³ using the filter paper method and Brazilian splitting test. The research findings reveal that during the drying process, as the water content decreases, the overall morphology of the pore size distributions remains largely consistent with a tri-modal distribution, in contrast to the bimodal distribution observed in compacted specimens. Furthermore, desiccated specimens exhibit better water retention behavior compared to compacted specimens. Additionally, compacted specimens reach their peak tensile strength at a critical water content, whereas desiccated specimens progressively increase their tensile strength until stabilizing. In the desiccated specimens, a significant amount of bonding material fills the soil pores, resulting in the formation of a stable bonding force between particles and aggregates. This phenomenon leads to a continuous increase in the tensile strength of the desiccated specimens. The study further establishes a tensile strength model that incorporates the influence of physicochemical forces. The accuracy and reliability of this model were confirmed by comparing its results with experimental data from the test soil in this study, as well as other available resources.