Laboratory Investigation on Strength Characteristics of Expansive Soil Treated with Jute Fiber Reinforcement

Abstract

Based on an extensive list of research work, expansive soil is renowned for its swelling-shrinkage property. Despite the wealth of research, the strength characteristics of expansive soil, which are more complicated than common clayey soil and characterized by a considerable loss of postpeak strength, have not been fully investigated. Within this area of study, soil reinforcement with discrete, short natural fibers is attracting increased attention in geotechnical applications, in part thanks to the unique advantages that this material possesses. Because of these possible advantages, the objectives of the study presented in this paper are (1) to investigate strategies for improving the strength characteristics of expansive soil through the introduction of jute fibers into soil mass and (2) to ascertain jute fibers’ reinforcing effects in relation to several important parameters known to control the effectiveness of fiber-reinforced expansive soil. The study presents discussions related to fiber content, fiber length, fiber orientation, water content, and dry density. More specifically, an experimental program of direct shear and triaxial compression tests was performed on unreinforced and reinforced specimens. The results demonstrate the beneficial role of jute fibers in enhancing strength parameters, enhancing deviator stress-strain behavior, and, if the considered parameters are properly selected, in reducing the postpeak strength loss of expansive soil. The study also presents a detailed discussion regarding the variation of the reinforcing effects and regarding the mechanisms accounting for how fiber-reinforcing effects are affected at the fiber and grain scale. Finally, limitations of this study and potential work for the future are contemplated.