Prediction of shear strength parameters in soil–lime mixture design – part 2: hydrated lime

In the field of lime stabilisation of soil, one of the main research objectives is optimisation of the mix design procedure. To this aim, correlations between strength parameters of treated soils and the main characteristics of lime treatment can be useful to have a preliminary estimation and reduce the number of laboratory tests to be performed in the design phase. This paper, part 2 of two companion papers, describes a comprehensive series of direct shear tests carried out on specimens of six soils with different characteristics treated with different amounts of hydrated lime (HL). In part 1, quicklime (QL) treatment is addressed with the same purpose. Good correlations between shear strength parameters and main soil–HL variables were obtained by multiple regression analyses and they were validated with data from the literature. The most significant predictors of the shear strength parameters were always found to be the clay fraction of the untreated soil and the lime content. In order to obtain an overall view of stabilisation possibilities, experimental results and predicted values for QL treatment formerly obtained by authors are discussed in this paper. This approach helps in the selection of the most suitable type of lime.