Microstructural Study of Soil Stabilization of the Southern Marl Using Lime and Nano-SiO2

Marlies are of problematic soils, which easily eroded when exposed to water flow and create problems in the sustainability of the developmental projects substrate. Using additives such as lime, cement and nanoparticles is one of the methods for soil chemical modification. The present study investigates the effect of lime and nano-SiO2 on the engineering properties of marl soil and formation of new compounds due to the stabilization process. In this regard, after determining the geotechnical properties of Marl soil, the improvement of engineering properties of the samples stabilized with different percentages of lime and nano-SiO2 has been evaluated at the end of the treatment period. In order to identify present minerals in the soil and investigate the formation of calcium silicate hydrate compounds in the reaction of soil with lime and nano-SiO2, the X-Ray Diffraction (XDR) test was conducted. The results showed that the presence of nano-SiO2 in the limestone system led to the uniform distribution of cement (C-S-H) compounds in the soil. Based on the results, with increasing the treatment time, lime participation in pozzolanic reactions was increased, also, the results obtained from the Atterberg limits test showed a diminution in the paste limit of the marl sample with increasing lime and nano-SiO2 values.