Experimental study of the effects of geogrids on elasticity modulus, brittleness, strength, and stress-strain behavior of lime stabilized kaolinitic clay

Abstract

Lime stabilization has been widely used in civil engineering to improve soils properties. A major shortcoming of lime is that it increases the soil brittleness. Thus, the aim of this research is to study the effect of lime along with geogrids on unconfined compressive strength (UCS) and modulus of elasticity (E_s) of the stabilized soil. Atterberg limits, XRF, and pH tests were performed to determine the optimal percentage of lime. Then, different percentages of lime were added to the soil to study strength, stress, and strain of specimens using UCS tests. Also, the effect of inclusion of geogrid on the lime stabilized soil was studied by adding four layers of geogrid in the soil at constant intervals. By increasing the percentages of lime, brittleness index, UCS, and E_s increased and deformability index decreased. Moreover, applying geogrids led to increasing deformability and failure strain. Based on SEM tests, an addition of lime caused fewer voids led to increasing UCS and E_s. A phenomenological model was used to develop equations for predicting UCS, E_s, brittleness, and deformability indexes for the stabilized soil. The results showed that there was a good correlation between the measured values and the estimated values given by the predicted equations.