Biopolymer-based sustainable stabilization using xanthan gum–cement composite for slope soil from Lohaghat, India

Climate change intensifies rainfall-induced landslides, necessitating sustainable ground improvement alternatives to carbon-intensive cement. This study innovatively employs the biopolymer xanthan gum to stabilize soil from a vulnerable slope in Lohaghat, India. A comprehensive evaluation of mechanical, durability and microstructural properties was conducted. Xanthan gum was added at dosages from 0.25% to 2.5% by soil weight, with 1% xanthan gum selected as the engineering optimum because it provided the most balanced overall engineering performance. Durability testing through six wetting–drying cycles showed moderate mass loss but maintained a substantial proportion of its initial strength and remained stronger than the untreated soil. Scanning electron microscopy and X-ray diffraction analyses confirmed a physical stabilization mechanism. To further enhance the performance, a novel composite was created by adding low cement content (2–6%) to the optimal biopolymer mix. This xanthan-cement combined effect increased unconfined compressive strength and cohesion. The findings demonstrate that xanthan gum and its hybrid composite provide an effective, eco-friendly slope stabilization solution. The proposed xanthan gum–cement composite demonstrated enhanced mechanical performance under the investigated laboratory conditions and contributes to the growing body of research on biopolymer-based stabilization for more sustainable geotechnical applications.