The use of various additives including polymer additives to modify the properties of bitumen used in road pavement construction was crucial for researchers to use modified bitumen in the asphalt significantly increased pavement and operational life of them. Accordingly, in this study the effect of lignin derived from waste paper companies Chukka (Wood and Paper industries of Iran) on the performance of bitumen based on laboratory practices have been investigated. Lignin including natural polymers that in the paper production process must be separated from the texture of wood, so papermaking waste treatment plants to be found in large quantities. In this study different weight percentages of lignin polymer (3, 6, 9 and 12%) has been mixed with bitumen 60-70 Isfahan refinery and its impact on the various properties of bitumen was studied. Add this polymer improves the performance characteristics of the bitumen at high temperatures. Increasing lignin reduces the penetration grade, increase viscosity, increase rotary viscosity and softening point of bitumen. Also by increasing lignin, bitumen thermal sensitivity is reduced which indicates better performance is bitumen for road construction.

Asphalt, this wonderful mixture that all of us deal with it every day. Perhaps the engineers in this domain as one of the solution have placed the modification of technical properties of asphalt on top of their activities for improvement of the features of this wonderful mixture. Modifying the technical properties of bitumen and asphalt has created many study opportunities all around the world. Along with it and in this article at first, with adding carbon nanotube with the amounts of 0.25, 0.50, 1 and 1.5 weight percent of base bitumen, the effect of this additive on mechanical properties of asphalt mixture was studied. In the continuation, the asphalt samples amplified with carbon nanotube for doing the Marshall Test were evaluated and tested. The results indicated that this additive causes to change in the Marshall test parameters such as increase of strength and reduction of flow. On the other hand, the special weight of asphalt mixture has faced with increase and the void space percent of aggregates faced with relative reduction. Also the void space percent of asphalt mixture and the percent of void space filled with bitumen were increased relatively. In the economic study of the effect of carbon nanotube on mixture, it was concluded that with gradual increase of carbon nanotube, the economical advantage of the project is reduced. Finally, with regard to the obtained results and analysis of the effect of this material on the bitumen and asphalt properties, it was concluded that this additive can be used in the regions with warm climate with heavy traffic and in the limited regions.