Tensile strength of compacted clays

The paper presents experimental results linking matric suction and tensile strength of compacted clays. Test results from a cohesive soil are presented and discussed with respect to the soil structure and the interaction of soil and water. It is assumed that two main groups of pores can be clearly identified in compacted clays; the pores between aggregates (interaggregate pores) and pores between particles (intraaggregate pores). Based on a description of soil-water-interaction an expected behaviour, describing tensile strength as a function of matric suction, is derived and compared with the experimental results. The laboratory test results indicate that there is a strong correlation between the pore size distribution (assessed by interpretation of the soil water characteristic curve SWCC) and the tensile strength of compacted soils. Furthermore, the test results are compared by using micro-mechanical considerations of the interaction between the skeleton of unsaturated soils (interparticle contact force) and by using numerical calculations with an elastic relationship.