Laboratory investigations on the behavior of CBR in two expanding soils reinforced with plant fibers of varying lengths and content

Abstract

Any structure built on soil with poor mechanical and physical properties, such as swelling soil, needs to be reinforced. Previous research has focused on the effects of additives such as lime, cement, and sand on these properties. On the other hand, current technological developments in soil reinforcement are leading to more cost-effective and environmentally friendly engineering solutions. In this context, using plant fibers in civil engineering, especially in geotechnical engineering, is considered a new technique to solve soil problems. This study aimed to investigate the effect of discrete, randomly distributed fibers on the heave of expansive soil. California Bearing Ratio or CBR tests were performed on two types of reworked expansive soils without and with fibers, varying the length and percentage of addition. This paper presents the results of an experimental program on the ability of fibers to inhibit the behavior of expansive soil. Three natural fibers (Alfa, jute, and sisal fibers) were used as reinforcement materials. These fibers were used in different percentages, namely 1%, 3%, 9%, and 18%, with three lengths (L1 = 10 mm L2 = 30 mm, and L3 = 90 mm) respectively. For a specific type of fiber. It was found that the improvement in swelling potential/pressure was a direct function of the length or percentage of fiber addition. The longest fiber is most effective at slowing down swelling to produce the optimum stabilization scenario. 18% has been suggested as the optimal content for all three types of fiber. On the other hand, higher inclusions might be a good option if the compression set is not a key problem. The study provides a solution for dealing with expansive soils before construction begins and is a step toward mitigating the disasters associated with infrastructure on expansive soils.