S. Hassan Firoozifar - Research Department, Pasargad Oil Company
Sanaz Forootan - Research Department, Pasargad Oil Company
Sara Forootan - Research Department, Pasargad Oil Company

Chemical composition and any variation of four main components of bitumen (asphaltene, saturated, naphtene aromatic and polar aromatic) have effective impact on its properties and especially, thermal properties. In other words, in order to have asphalt pavements with reasonable temperature susceptibility and thermal stability, first of all it is essential to know the effect of these components on bitumen properties. Therefor, in this research these effects were investigated and it was found that penetration index (PI) and penetration viscosity number (PVN) of bitumen were increased with increasing in asphaltene content. Hardening of bitumen is the most important phenomenon which results in destruction of pavement. Finally, this is to investigate the effect of bitumen aging on thermal properties of bitumen, it was concluded that more asphaltene content of bitumen reduces the negative aging impact; also reduces the temperature susceptibility of bitumen. Furthermore, the thermal behavior of bitumen in an oxidizing environment was studied using thermogravimetric analysis (TGA). The results showed that increasing the asphaltene content of bitumen decreases the temperature susceptibility and improves the resistance of samples to thermal decomposition.

Bitumen, Asphaltene, Tempreture susceptibility, PI, TGA