Stabilization of clay soil with glass powder

Abstract

Soils in construction sites are not always favourable and often their mechanical properties need to be improved by mixing the soil with other stabilizing materials. In this research, Shiraz clay soil with a specific gravity of 2.65 and an optimal moisture content of 17% was stabilized with glass powder (GP) with content ratios of 0, 5, 10, 15, 20 and 25% in order to improve the soil properties. Then Atterberg limit tests, consolidation tests, uniaxial compression tests, direct shear tests and compaction tests were performed on samples with different GP contents to evaluate the effects of the GP on the stability and strength of the clay. The results showed that, by increasing the glass powder content of the clay, the Atterberg limits decreased. A correlation was observed between adding glass powder and consolidation indexes. The soil samples without glass powder showed the highest void ratio, which decreased with increasing pressure. The inclusion of 5%, 10%, 15%, and 20% glass powder yielded a distinct void ratio pattern during consolidation tests. The highest compressive strength of the samples was observed for the soil with 15% glass powder. As the glass powder content increased up to 20%, the optimum moisture content (OMC) decreased, and the maximum dry density (MDD) increased. The results suggest a range of 15% to 20% glass powder content as optimal for enhancing the strength of stabilized clay without utilizing any alkali-activated materials. Scanning electron microscopy analysis provided visual insight into the microstructure, showcasing the interaction between glass powder and clay at varying concentrations.