The study investigated the aging properties of the degree of penetration of modified asphalt PG 76-22 (binder). Aging was simulated using the rolling film kiln (RTFOT) and pressure aging vessel (PAV) for short and long term aging during the production and placement of asphalt mixtures, although the actual aging time at Long term varies depending on time of paving and use. Empirical tests, including penetration and softening points, were carried out to determine the consistency of the binder and also the viscosity of the binder was investigated before and after aging. The RTFOT was carried out at 1630 ° C for 85 minutes and PAV for 20 hours. The results of the study indicated that aging resulted in the oxidation of the bitumen with increasing stiffness of the binder. Aging was observed to increase viscosity, decrease binder penetration and increase the softening point of modified bitumen. It could be concluded that aging increases hardness, thus decreasing penetration and increasing the softening point of the binder and viscosity.

Bitumen aging usually results from the weathering of the binder due to oxidation. The aging of the bitumen is one of the main factors that cause the deterioration of the pavements of asphalt concrete. Modes of aging failures include fatigue, thermal inducing cracks, and fading. In practice, real time for short- and long-term aging at construction sites varies and depends on trawl distances and the period of use of the pavement John, R. and W. David (2003). There are two basic mechanisms involved in the aging of the binder, which include an irreversible process, such as the chemical changes of bitumen, which consist of the oxidation of the bitumen molecules and the loss of volatile components that subsequently influence the rheological properties of the binders . The reversible process is the second mechanism called physical hardening; This involves the reorganization of the molecular structure of the binder, under specific conditions. Xiaohu, L. and U. Issacsson (2002).

The aging of the bitumen can be attributed to some factors including the characteristics of the binder and its content in the mixture, the nature of the aggregates and the distribution of particle size, the empty air content in the mixture. Other factors include production-related parameters such as temperature and time Edwards, Y. and U. Issacsson (2005). In this study, the rolling thin film oven test (RTFOT) was used to simulate short-term aging and the pressure aging vessel (PAV). The RTFOT measures the effect of heat and air on a moving film of semisolid asphalt binder. The temperature of the 1630C test and the time for the RTFO test is 85 min which is expected to produce aging effects comparable to the average site conditions. Annual Book of ASTM Standards (2006).