Improvement of Highway Materials

Abstract

The performance of paved and unpaved roads is often poor after every monsoon and, in most cases; these pavements show cracking, potholes and serious differential settlement at various locations. Therefore, it is of utmost importance considering the design and construction methodology to maintain and improve the performance of such pavements. Attempts have been made in our project to demonstrate the potential of reclaimed High Density Polyethylene strips (HDPE) and Jute Fibre as soil reinforcement for improving engineering performance of subgrade soil. HDPE strips obtained from waste plastic were mixed randomly with the soil. Jute fibres (in the form of jute threads) were obtained from waste jute bags. A series of California Bearing Ratio (CBR) tests were carried out on randomly reinforced soil by varying percentage of HDPE strips and jute threads with different lengths and proportions. Results of CBR tests demonstrated that inclusion of waste HDPE strips and jute threads in soil with appropriate amounts improved strength and deformation behaviour of subgrade soils substantially. The proposed technique can be used to advantage in embankment/road construction. The experimentation at several institutes indicated that the waste plastic, when added to bitumen will form a fine coat of plastic over the bitumen and such bitumen, when mixed with the aggregate is found to give higher strength, higher resistance to water and better performance over a period of time. Sulphur added bitumen can be a far better substitute of bitumen used in road construction. It is a less expensive application when used as a thin top course over failed pavement that would otherwise need replacement