Improving the Soil Subgrade with Plastic Waste Reinforcement

Improving the Soil Subgrade with Plastic Waste Reinforcement—An Experimental Study

Shah, Alka / Modha, Hiral

Abstract The subgrade soil is an integral part of pavements which provides support to the pavement. The behaviour of road surface depends on the strength of filling material and the subgrade below it. The pavements are vulnerably affected by the change in subgrade soil properties due to water-table fluctuation, overloading, flooding, etc. This study focuses on improving the strength of soil subgrade using plastic waste soil reinforcement technique in pavement construction, looking to the current environmental issue related to the utilisation of waste plastic, as plastic is a non-biodegradable material. In this study, geocell and geogrid were prepared from plastic waste and used as soil reinforcement. The plastic waste geocell and geogrid were placed at different depths from the top of the CBR mould. The CBR test was performed for unsoaked condition of virgin soil and reinforced soil, and the behaviour of load versus penetration was observed. The results show that by placing plastic waste reinforcement at different depths, the strength of the reinforced subgrade soil considerably increased with respect to virgin soil. The confined structure of plastic waste geocell shows significant strength improvement compared to plastic waste geogrid. The result shows that the significant improvement in strength of soil using geogrid and geocell was effective at a particular depth. This study reveals that the use of plastic waste for improving subgrade soil strength is a good option. The plastic waste can be utilised in pavement construction as well as it can be the cost-effective solution.