Stabilization of expansive soil with agricultural waste additives: a review

Abstract

AbstractSoil is one of the most important construction materials in the world. It has been effectively exploited for various purposes, such as building social infrastructures, growing agricultural products, and promoting many other important activities that can be useful for human life. The nature of the soil is uncertain from one place to another due to its physical, chemical, and mechanical properties. The expansive type of soil is the most problematic soil and causes damage to the foundations of roads and buildings. On the other hand, solid agricultural waste is widely available and is also a serious problem for the environment and its ecosystem. Therefore, improving the property of problematic soil by using sustainable, locally available, and low-cost agricultural waste materials is required. This paper aims to review the existing knowledge and practices from the recently published state-of-the-art journals related to expansive soil stabilization by agricultural waste additives and to support the findings with scientific data analysis. The effect of using agricultural waste additives such as coffee husk, rice husk, sawdust, wheat straw, cornhusk, sugarcane bagasse, and bamboo powder was carefully evaluated in terms of geotechnical characteristics, and strength parameters. As a result of the review, agricultural waste additives improved California Bearing Ratio (CBR), Plastic Index (PI), and Unconfined Compressive Strength (UCS) values, significantly lowered Optimum Moisture Content (OMC) and increased the Maximum Dry Density (MDD) of the soil. Furthermore, the effects of microstructural composition, morphology, and changes in expansive soils treated with agricultural waste additives were analyzed based on the XRD test results and SEM image analysis.