Performance Evaluation of Fatigue and Moisture Susceptibility of HMA Containing PET

Abstract

Strength, sustainability, and durability are the fundamental prerequisites of pavement structure. To achieve these objectives, a variety of mixing techniques are employed, which may include the addition of polymers such as PET, to create a sustainable asphalt pavement structure. The durability of the Hot Mix Asphalt (HMA) is evaluated by performance parameters such as fatigue and moisture susceptibility, among others. Utilizing PET which is crushed bottle waste in asphalt mix yield in economical, sustainable, environmentally friendly pavements. With the use of plastics in the roads, the durability of pavement structure can be increased to many folds and the waste plastic material can be utilized which go untreated otherwise. It is, therefore, the most suitable option to utilize waste plastic material in a way that contributes significantly and positively in another field of life. Advantages of using PET in road construction is internationally known and is also used on an industrial scale I countries including India, Australia and Korea. Keeping the potential benefits of using PET as an additive in Asphalt mixtures using local material and in local construction environment, this research focuses on evaluating the performance of HMA by using polyethylene Terephthalate (PET) in certain replacement of optimum virgin bitumen. NHA Gradation-B, ARL Grade 60/70 Asphalt, Khanpur crush, crushed PET waste from a local plastic shredder from Rawalpindi, Pakistan was utilized as research material in the very study. Rheological testing was conducted on virgin asphalt as well as polymer modified asphalt which includes penetration, softening point, viscosity and ductility test. Furthermore, various volumetric properties of HMA samples were also studied using Marshall Testing and Optimum Bitumen Content was evaluated. Later different mixes of HMA were prepared with varying percentages of PET (0%, 2%, 4%, 8% and 10%) through Marshall Mix design using wet and dry mixing technique. The fatigue behaviour of asphalt mixes was evaluated using Indirect Tensile Fatigue Test (ITFT), while susceptibility to moisture damage of HMA was evaluated by Moisture Susceptibility Test. Results obtained clarified that fatigue resistance and resistance to moisture damage improved significantly with the optimum increase in percentages of PET. Dry mixing technique yielded better results for ITFT, while wet mixing technique yielded better results for wet mixing technique. PET modification of HMAxvii yields cost effective, sustainable and environmental friendly pavements which is beneficial for countries like Pakistan where financial funding as well as waste management is an issue.