Improvement in Engineering Behaviour of Expansive Soil Reinforced with Randomly Distributed Waste Plastic Strips

Abstract

With rapid urbanisation in developing countries like India, there is an increase in the generation of plastic wastes. Disposal of these plastic wastes creates not only environmental issues but also consumes a large area of lands as landfills. Furthermore, due to no availability of sufficient recycling facility in India, most of the waste plastic could not be reused. Utilisation of these plastic wastes for construction purposes can not only solve the waste disposal problem but also create a sustainable construction methodology. The performance of pavement construction over expansive soil subgrade is greatly affected by moisture content in the soil. During monsoon/rainy season, expansive soil properties change drastically due to increase in moisture content. Due to migration of moisture content into the expansive soil, the volume of soil increases but strength reduces significantly. This variation in volume and strength may lead to catastrophic failure of the pavement. Therefore, it has become very much vital to adopt innovative construction approach to counteract the damaging effect of expansive soil subgrade. In this study, a new approach was attempted to study the effectiveness of polyethylene terephthalate (PETE) strips obtained from waste plastic glass as a reinforcing agent to improve the engineering properties of expansive soil. California Bearing Ratio (CBR) tests were performed to study the effect of plastic strip content and size of the plastic strip on swelling and strength behaviour of plastic reinforced expansive soil samples in series. The plastic strip length (10–30 mm) and quantity (0–4% by weight of soil) were varied to study the effect of the plastic reinforcement on the properties of the expansive soil. After the completion of series of experiments, it was observed that there was a significant improvement in the strength and swelling characteristics of the soil with polymer reinforcement to the expansive soil.