Reduction of Optimum Bitumen Content in Polyethylene Modified Bituminous Mixes

Using plastic as additive in pavement has gained popularity for the past several years. Plastics waste is a serious environmental issue due to its non-biodegradable properties and hard to be disposed. There is a high demand of plastics in the industries as a packaging and disposable consumer items due to its inexpensive, lightweight and durable properties. Polyethylene (PE) has been extensively used in packaging, pipes, toys, garbage bags and bottles. The purpose of this study is to evaluate the properties of PE modified bituminous mixture in comparison to conventional bituminous mixture. This study utilized both High Density Polyethylene (HDPE) and Low Density Polyethylene (LDPE) granules in order to achieve optimum benefits. Wearing course samples were prepared using Marshall Mix design method and according to Standard Specification for Road Works as guidelines. Laboratory study was performed on the compacted mixtures to determine the optimum bitumen content (OBC) and evaluate the effect of PE on its properties. The modified mixes show promising results: higher stability and lower optimum bitumen content (OBC) when compared to a conventional mix. The results indicate that the addition of 2% Polyethylene by weight of aggregate reduce the amount of OBC by 4.2%. Hence, Polyethylene modified bituminous mixture not only can helps reduce the waste plastics but also results in saving in pavement material costs.