The Effect of Variation in Water Compaction and Blending Approach on the Performance of Gypsum-Based Soil Stabilized with Cement and Silica Fume

الملخص

The performance of chemical stabilization of gypseous soil, a conventional technique, relies on several aspects, i.e., soil structure, stibilzer combination, sulphate concentration, and water content etc. This research studies the impact of using various water contents and different mixing approaches on the behaviour of gypsum-based soil stabilized by varying proportions of cement (C) and silica fume (S). In this context, a series of gypseous soil samples was prepared by utilizing a blended combination of 7S-3S and 5C-5S, various water contents, and two blending approaches (dry-based blending (DM) and slurry-based blending approach (SM)). Then, the prepared gypseous soil samples were exposed to several engineering tests, entailing the compressive strength (UCS) and linear expansion invistigations. The outcomes revealed that utilizing SM in the fabrication of specimens led to a deteriorative impact on the UCS and swelling values. This deterioration is due to the clumping of cementitious compounds and the inhomogeneous distribution of hydrated materials produced during the chemical interaction. Conversely, the utilization of various water contents showed a deterioration in UCS values and an improvement in swelling values, possibly due to the extension of void geometry, thus reducing the hardness of soil against deformation and easing the faster ettringite growth.