Amirkabir University of Technology AUT Journal of Civil Engineering 2588-2899 1 2 2017 12 01 Comparison of Rut Susceptibility Parameters in Modified Bitumen with PPA 129 134 2736 10.22060/ceej.2017.12383.5198 EN M. Khodadadi Department of Civil & Environmental Engineering, Amirkabir University of Technology (Polytechnic), Tehran, Iran F. Moghadas Nejad Department of Civil & Environmental Engineering, Amirkabir University of Technology (Polytechnic), Tehran, Iran A. Khodaii Department of Civil & Environmental Engineering, Amirkabir University of Technology (Polytechnic), Tehran, Iran ABSTRACT: Journal Article 2017 01 09 Pavement as a multi-layer structure is subjected to various distress mechanisms such<br />as permanent deformation (Rutting) in its service time. Rutting resistance evaluation is one of the<br />important components of pavement management system which plays a substantial role in the effective<br />strategic development of pavement rehabilitation and maintenance. Improving the rheological properties<br />of bitumen using one of the various additives is one of the practical approaches to reduce the rutting<br />potential in the asphalt mixture. In this study, basic bitumen with an 85/100 penetration grade (PG58-22)<br />was modified by 0.5, 1.0 and 1.5% poly phosphoric acid by weight of bitumen. The rutting resistance<br />improvement of modified bitumen was investigated according to Superpave protocol. For this purpose,<br />temperature sweep and frequency sweep tests were performed on all bitumen at 46, 52 and 58 oC. Also,<br />rutting resistance improvement ratio was calculated based on the Superpave specification (|G*|/sinδ),<br />Shenoy specification (|G*|/[1-(1/sinδ×tanδ)]) and zero shear viscosity. This ratio was employed to rank<br />these specifications. The results of this study represent an improvement in rutting resistance of modified<br />bitumen. According to specification ranking results, it can be concluded that zero shear viscosity has more<br />potential and credibility to predict rutting damage occurrence as compared to Superpave specification<br />and Shenoy specification. https://ajce.aut.ac.ir/article_2736_47fd3c87f42f55d4b233417d49c34783.pdf