The Effect of Carbon Black on Moisture Performance of Asphalt Pavements

In this study, the effects of carbon black (CB) additive obtained from waste tires on the moisture performance of hot mix asphalt pavements were investigated. For this purpose, modified asphalts were prepared by adding 5%, 10%, 15% and 20% CB by weight to pure asphalt with penetration class B 160/220. Physical properties of pure and modified asphalts were determined by penetration, softening point and ductility tests, and workability properties were determined by rotational viscometer (RV) test. Then, the optimum asphalt content of the mixture was determined according to Marshall design method by using aggregate and pure asphalt for mixture design. Based on this determined ratio, pure and modified asphalts and hot mix samples were prepared. Pure and CB added modified mixture samples were subjected to Marshall stability, retained Marshall stability (RMS) and indirect tensile strength (ITS) tests. According to the physical test results, it was observed that the hardness and workability temperatures of the modified binders increased with the CB additive. According to the test results of the mixture, it was observed that CB additive had an improving effect on the moisture performance of road pavements due to the significant increases in Marshall stability, RMS and indirect tensile strength ratio (ITSR) values, especially at the rate of 10% CB.