Stabilization of Expansive Soil Using Cementitious Materials with Non-Woven Geotextile

This research employed cementitious materials to alter the engineering characteristics of expansive soil. Tests were conducted on both treated and untreated soil samples, using different proportions of cementitious materials, while reinforcement was achieved with non-woven geotextile. The evaluated parameters included free swell index, compaction, unconfined compressive strength, California bearing ratio and expansion ratio. The standard proctor test was conducted on different proposed proportions to achieve an optimal mix. After a curing period of 28 days, the unconfined compressive strength and California bearing ratio values showed significant improvements. As the percentage of cementitious materials increases, both the expansion ratio and free swell index values exhibit a linear decrease. The rationale for these changes can be comprehended through the application of various analytical techniques, including Field emission scanning electron microscopy, Energy dispersive spectroscopy, X-ray fluorescence, X-ray diffraction and Fourier transform infrared spectroscopy. Field emission scanning electron microscopy reveals the formation of impermeable calcium silicate hydrate and calcium aluminate hydrate gels within the soil structure. Elemental compositions were derived from the analyses of Energy dispersive spectroscopy and X-ray fluorescence. The soil stabilized with cementitious materials exhibited the development of cementitious chemicals, as evidenced by the emergence of several additional peaks in both X-ray diffraction and Fourier transform infrared spectroscopy analyses. This study is useful for the subgrade of heavily used highways that can be modified by using cementitious materials during the construction of flexible pavements on expansive soil.