Use Of Reclaimed Asphalt Pavement (RAP)

There is a significant amount of asphalt pavement to be reconstructed every year in China. If the current pavement maintenance technology is employed, much asphalt material will be abandoned, whose amount will increase with the augment of maintained asphalt pavement. Landfills have to be built to place the abandoned materials, polluting the environment and wasting the resource, especially in China, which lack high quality asphalt.This paper systematically studies the theory, experiment and practice of the use of reclaimed asphalt pavement (RAP). Firstly, the author analyzes the properties of asphalt binder by extraction and recovery experiment, mixture effects study, and chemical component analysis. Penetration, ductility and aromatic substance decrease, while softening point and viscosity increase. The author improves traditional extraction and recovery procedure, and advances a new method to extraction asphalt, which overcoming some limitations of old one.Secondly, the author analyzes the mechanism of asphalt aging and the practicable asphalt reclamation, adds rejuvenating agent to aged asphalt, then studies RAP properties. The author also mixes RAP and original asphalt and studies the mixture properties. The fact is that rejuvenating agent can improve the properties of aged asphalt. The mixture of RAP and original asphalt satisfies the requirement.Thirdly, the author designs RAP mixture and studies its pavement performance. The main factors are the ratio of RAP and original asphalt, and the amount of rejuvenating agent.