Experimental study to examine the independent roles of lime and cement on the stabilization of a mountain soil: A comparative study

The durability, efficiency and the integrity of structures built within or over mountain soils are mainly controlled by the geotechnical properties. It is therefore imperative to analyse these properties before the commencement of such projects, and upgrade them when and where required. The current study focusses on the addressing the problems associated with soil failure that occur during the construction and widening of roads and highways in the area of interest. The soil samples, which were collected from the study area, were stabilized using two types of readily-available additives, namely, lime and cement. The outcomes of the study indicate the dependence of the geotechnical and microstructural properties on the type of additive used. The comparative analysis suggests that the cement has a relatively higher influence on the mechanical behaviour of soil when compared to that of lime. Additionally, the compressive strength of the samples that had been cured for 28 days increased nearly four to six times than that of the untreated specimen, thereby suggesting the influence of curing time on the strength parameters. The increase in compressive strength can be attributed to the chemical transformations that occur in the soil on the addition of additives. The cation exchange and pozzolanic reactions resulted in the formation of cementitious compounds within the soil matrix, which was observed by performing X-ray diffraction (XRD), scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FTIR) analysis. The present study suggests that satisfactory strength can be achieved with the addition of 5% additives to the soil mixture, which will save the cost of stabilization subsequently.