ABSTRACT
The main objective of this research is to investigate the long term performance of asphalt concrete mixtures using wastes of polyethylene and polyester. To achieve this objective, Control mix (CM) was designed by Marshall mix method without any additives then cores with wastes of polyethylene and polyester fibers were prepared and tested for their properties. The testing program included advanced tests to evaluate the long term performance of CM and two selected mixes using additives as determined by earlier studies. Advanced tests included rutting resistance test, indirect tensile strength test and resilient modulus test. For medium density polyethylene (MDPE), 4% MDPE by weight of bitumen, was used for 10 min. mixing time at 165°C mixing temperature to prepare the polyethylene (PE) mix while 0.35% polyester of 1cm fiber length was used for polyester (PS) mix. The indirect tensile strength (ITS) values of the specimens containing fibers were higher than that of CM samples. Values of ITS increased by 18% and 15% for PE and PS mixes compared to that value for CM. The results of resilient modulus test confirm that performance of PE and PS mixes were better compared to CM at 25°C, which is a sign of high resistance to cracking. The resilient modulus value has improved by 35% for PE mix compared to CM while it has improved by 20 % for PS mix. The results of wheel tracking test showed that the rut depths of PE and PS mixes were less than that of CM at 60°C, rut depth was reduced by 30% and 40%, compared to rut depth of CM, using PE and PS additives, respectively. The results of this research demonstrate the benefit of using polyethylene and polyester additives to enhance long term performance of asphalt mixtures.