Subgrade stabilization using non-biodegradable waste material

Abstract

Non-biodegradable waste materials pose a major environmental threat. The need for their safe discarding has increased. Incorporation of non-biodegradable waste materials in various engineering applications such as in highways and runways, etc., has been among main agendas of geotechnical engineers. In this paper, the results of testing to evaluate the effect of using non-biodegradable waste rubber powder in soft soils as an additive is reported. The soil behavior has been characterized by CBR as the intention is to use the in situ soil after the inclusion of the waste rubber material in road sub-grades so that the necessity of transporting good soil from borrow pits is eliminated. This will result in economic and environmental benefits. With the inclusion of non-biodegradable waste material, numbers of CBR tests were performed on soil samples. Non-biodegradable waste rubber powder is added to soil in different percentages as 0.5, 1, 1.5, 2, 2.5, 3, 3.5, 4, 5, 6, 7, 8, and 10% of dry weight of soil. The testing process was carried to check the consequences of using non-biodegradable waste material on CBR values of soil subgrade. The results showed that the use of non-biodegradable waste materials for soil stabilization improved the CBR properties of soil. The optimum value of rubber powder that can be added to soil is found out to be 7% of dry weight of soil. Further increase of rubber power after 7% resulted in a decrease in the CBR value.