Erosion control performance of geotextiles treated with alkali-activated binder reinforced slope

Soil erosion is a global environmental issue that can trigger disasters. This study evaluated the effectiveness of alkali-activated binder (AAB) treatment on the performance of natural geotextiles (coir mats and straw mats) in controlling slope erosion through field-based artificial rainfall experiments. The results demonstrated that AAB treatment significantly improved the microstructure and mechanical properties of the geotextiles. The tensile strength of AAB-treated coir mats increased by 20%, with an elongation at break of 54.6%. Under a rainfall intensity of 120 mm/h and a slope gradient of 1:1, AAB-treated coir mats reduced the peak runoff rate by 70% and the peak erosion rate by 8.8% compared to bare slopes. High-intensity rainfall drives rapid yet spatially heterogeneous water movement. While the 1:1.75 gradient enhances infiltration depth and soil moisture uniformity, the 1:1 slope induces surface runoff, resulting in maximum water accumulation at the slope base. Alkali-activation reactions in AAB-functionalized geosynthetics produce cementitious phases that refine pore networks, increasing the stabilized water content of slope soils by 10% to 15%. These microstructural modifications concurrently enhance moisture retention capacity and erosion resistance in vegetated slope systems.