Peningkatan Parameter Kuat Geser Clay Shale Menggunakan Xanthan Gum Modifikasi Polyvinyl Alcohol (PVA)

Abstract

The highly expansive characteristics of clay shale lead to several issues in construction. This study aimed to evaluate the use of xanthan gum (XG), polyvinyl alcohol (PVA), and their combination to improve the shear strength parameters of clay shale. A series of experiments were performed, starting from physical property tests, including specific gravity, gradation, and Atterberg limits, and mechanical property tests using the direct shear test to evaluate the effect of the addition of Xanthan Gum and polyvinyl alcohol or their combination on the soil parameters. Xanthan gum and polyvinyl alcohol were mixed with clay shale using dry and wet mixing methods. The study results show that adding xanthan gum and polyvinyl alcohol, and their combination, improves the plasticity index by 156%, 98%, and 6%, respectively. The modification of XG using polyvinyl alcohol was also reported to increase the cohesion and internal friction angle by 200% and 103%, respectively. This study concludes that the addition of polyvinyl alcohol as a modification of xanthan gum is an effective way to improve the soil strength of clay shale.