Investigation of Aged Asphalt Film Transfer during Hot In-Place Recycling of Asphalt Pavement

The aged asphalt film transfer between new and old aggregate during hot in-place recycling of asphalt pavement was investigated in this paper. The mechanism of asphalt film transfer between new and old mixture was analyzed by connective mass transfer theory. Based on the theoretical analysis, influence factors for asphalt film transfer during hot in-place recycling were summarized. Then laboratory tests simulating the file hot in-place recycling process were conducted to investigated the asphalt film transfer between new and old aggregate based on different influence factors design. The test results indicated that preheating temperature, mixing time and recycling agent are the key influence factors during hot in-place recycling process. Suggestions to guarantee the quality of hot in-place recycling asphalt mixture were given in this paper.