%0 Journal Article %T Comparison of Rut Susceptibility Parameters in Modified Bitumen with PPA %J AUT Journal of Civil Engineering %I Amirkabir University of Technology %Z 2588-2899 %A Khodadadi, M. %A Moghadas Nejad, F. %A Khodaii, A. %D 2017 %\ 12/01/2017 %V 1 %N 2 %P 129-134 %! Comparison of Rut Susceptibility Parameters in Modified Bitumen with PPA %K Rutting of Asphalt Mixture %K Rheological Properties of Modified Bitumen %K Superpave Protocol %K Zero Shear Viscosity %K Poly Phosphoric Acid %R 10.22060/ceej.2017.12383.5198 %X Pavement as a multi-layer structure is subjected to various distress mechanisms suchas permanent deformation (Rutting) in its service time. Rutting resistance evaluation is one of theimportant components of pavement management system which plays a substantial role in the effectivestrategic development of pavement rehabilitation and maintenance. Improving the rheological propertiesof bitumen using one of the various additives is one of the practical approaches to reduce the ruttingpotential in the asphalt mixture. In this study, basic bitumen with an 85/100 penetration grade (PG58-22)was modified by 0.5, 1.0 and 1.5% poly phosphoric acid by weight of bitumen. The rutting resistanceimprovement of modified bitumen was investigated according to Superpave protocol. For this purpose,temperature sweep and frequency sweep tests were performed on all bitumen at 46, 52 and 58 oC. Also,rutting resistance improvement ratio was calculated based on the Superpave specification (|G*|/sinδ),Shenoy specification (|G*|/[1-(1/sinδ×tanδ)]) and zero shear viscosity. This ratio was employed to rankthese specifications. The results of this study represent an improvement in rutting resistance of modifiedbitumen. According to specification ranking results, it can be concluded that zero shear viscosity has morepotential and credibility to predict rutting damage occurrence as compared to Superpave specificationand Shenoy specification. %U https://ajce.aut.ac.ir/article_2736_e0fe1ef2bfb7664bdee7070c0ce8f7ee.pdf