Ali Asghar Roghanizad - Chemical engineering faculty of Amirkabir Univrsity
Azam Jalali - Polymer engineering faculty of Amirkabir Univrsity.
Taghi Bahrami - Civil and Enviromental engineering faculty of Amirkabir Univrsity
Arezoo Saket - Chemical engineering faculty of Amirkabir Univrsity.

Bitumen has been used for a variety of purposes, but most importantly for road surfacing. Bitumen has been known as a good binder in paving application because of its special interesting characteristics, but increasing traffic loading and volumes on roads has led to the use of modifiers to improve the performance of bitumen. In this work precipitated calcium carbonate coated by thin layer of a polymeric compound (named as P.C.C.) has been used as a modifier for bitumen. Bitumen mixtures contained different amount of this material were prepared. Then the effects of P.C.C. addition on the bitumen performance were evaluated through common tests such as penetration, softening point, kinematic viscosity and temperature susceptibility. The modified bitumen was used in the asphalt and its performance was studied. The obtained results showed that, using of (P.C.C.) increases dramatically Marshall Number and eliminates rutting at tropical regions. According to the results a mechanism for the effect of P.C.C. was illustrated.

bitumen, softening point, P.C.C., modified