CBR Characteristics of Layered Black Cotton Soil Stabilized with Red Stone Dust and Geosynthetics

Abstract

Geosynthetic materials play a pivotal role in addressing the challenges associated with black cotton soil, a problematic soil type prone to volume changes and exhibiting high plasticity. The primary objective is to enhance the strength properties of black cotton soil through a two-step process. Initially, the soil is stabilized by incorporating varying percentages (5%, 10%, 15%, 20%, 25%, 30%, and 35%) of red stone dust waste. Subsequently, to prepare the stabilized soil for use as a subgrade, geosynthetics are employed for reinforcement, with placement at different depths in both single and double layers. California Bearing Ratio (CBR) tests serve as a key assessment tool for the blends of Black Cotton Soil (BCS) and Red Stone Dust (RSD) with geotextile and geogrid reinforcement. The geosynthetic materials are strategically placed at depths of H/3 and 2H/3 from the top of the loading surface. Among the tested blends, those containing 25% RSD exhibit the most promising results in terms of CBR improvement. Moreover, the study reveals that the incorporation of additional reinforcement in a single layer yields more substantial enhancements in CBR values compared to the double-layer reinforcement approach. Specifically, the findings highlight that a single layer of geogrid, positioned at H/3 depth, outperforms geotextile in a single layer. This research contributes valuable insights into optimizing the stabilization and reinforcement of black cotton soil using a combination of red stone dust waste and geosynthetic materials, offering a comprehensive understanding of the interplay between various parameters for effective soil engineering solutions.