Mechanistic behaviour under traffic load of a clayey silt modified with lime

The behaviour under traffic loads of a soil modified with lime was researched through a laboratorial mechanistic approach. A clayey silty soil from Cebollatí, eastern Uruguay, and a commercial calcic lime were used. Cyclic triaxial compression tests were carried out on the soil treated with different lime contents, curing periods and dry densities in order to study its resilient behaviour. The fatigue life was investigated through cyclic indirect diametrical tensile tests by varying the lime content and curing period. A model of resilient modulus as power function of the deviator stress was found, independent of the lime content and curing period and dependent on the compaction effort. The model is similar to that observed in the natural soil, which means that the treated soil behaves as modified material. Nevertheless, the material is susceptible to fatigue cracking. The fatigue life, expressed as the number of load cycles up to break, is an inverse power function of the initial tensile strain, being most sensitive to that parameter. It was found that the fatigue life can be better explained when expressed as function of the ratio between the initial tensile strain and the tensile stain at break.