ABSTRACT
In this paper the economic benefit of using wastes of polyethylene and polyester in asphalt mixes was investigated. The objective of this research was accomplished through using the properties of three different mixes; control mix (CM) polyethylene mix (PE) and polyester mix (PS). For polyethylene, 4% by weight of optimum bitumen content, determined by Marshall Mix Design Method, was added to the asphalt mixture. Polyester fibers were also used with fiber length of 1 cm and a percentage of 0.35% by total mix weight. To conduct an economical study, thickness of the surface layer was determined by AASHTO Design Method based on the resilient moduli of CM, PE, and PS. The results showed that the thickness of surface layer was reduced by 13% when adding polyethylene waste and by 9% when adding polyester waste. Design life was also calculated using the Kenlayer program. For single wheels, the results showed that design life of the pavement containing polyethylene was higher by 19% compared to that of the CM. This percentage was 15% when polyester fibers were used. Under dual-tandem wheels, the design life of the pavement increased by 11% and 8% for PE and PS mixes respectively compared to the CM.