Experimental characterization of rutting performance of Polyethylene Terephthalate modified asphalt mixtures under static and dynamic loads

• Properties of PET modified asphalt mixtures were investigated.
• Rutting behavior of asphalt mixtures was assessed.
• Static and dynamic loadings were designated.
• PET modified mixtures demonstrated different behaviors under static and dynamic loadings.

During the last decades by increasing vehicles’ number and weights on roads, road pavement has been subjected to greater damages which in many cases occurred even before expected pavement service life. Hence, in order to tackle with this problem road designers and engineers are to find solutions to improve pavement characteristics. One of the most common solutions is constructing asphalt mixture with modified characteristics. This paper aims to evaluate effects of using waste Polyethylene Terephthalate (PET) as a modifier on properties of asphalt mixture in three steps. In the first step, bulk specific gravity test, Marshall test, indirect tensile stiffness modulus test and indirect tensile strength test were conducted on mixtures containing different percentages of PET. In the second step, permanent deformation of PET modified asphalt mixture were assessed under static and dynamic loads. Finally in the last step, relationships were found between the results achieved in the first and second steps. The results showed that using PET as additive can change the properties of asphalt mixture. PET modified mixtures had entirely different behaviors under static and dynamic loadings and when it could not be considered as a proper additive for pavements experiencing static loading, it was a superior additive which can considerably improve rutting properties of asphalt mixture under dynamic loading condition.