Evaluation of Improving the Resistance of Marl Soils Stabilized With Nanosilica by Cement and Lime (Case Study: Marl Soil around Kazeron City)

Chemical soil improvement using lime and nanosilica has been used for long-term improvement of geotechnical properties as well as stabilization process. The purpose is to investigate the microstructural characteristics and geotechnical characteristics of marl soils and provide a solution to improve the properties and engineering characteristics of these soils. In this regard, the effect of lime addition and the combination of lime and nanosilica on the microstructural and geotechnical characteristics of the soil was investigated. After taking the marl soil samples around Kazerun city, the samples were transferred to the laboratory in order to determine the physical, chemical and mechanical properties and classification of the soil, Etterberg limits, density and unconfined compressive strength on the base soil. The stabilization of marl soil by adding lime and nanocomposite with different percentages of soil dry weight was evaluated by uniaxial strength test. The required samples were prepared with different proportions of cement and microsilica in optimal humidity and after curing, they were subjected to unconfined compressive strength (UCS), California bearing ratio (CBR) and pH tests. The Etterberg limit test was performed after several days of curing on different soil-lime-nanosilica combinations. The results of the experiments showed that by adding 3% nanosilica and 4% lime for the adhesion parameter, and also by adding 1% nanosilica and 2% lime for the internal friction angle parameter, the optimum value of the additive was obtained. The presence of nanosilica in the soil-lime system led to the uniform distribution of hydrated calcium silicate compounds in the soil.