2005 Volume 48 Issue 6 Pages 358-364
A new recycling technology is proposed for separating and recovering aggregate and binder from asphalt pavement waste to develop a sustainable asphalt pavement recycling system. Investigation of the system used water as the solvent, which is the most convenient, economic and safe solvent for humans and the environment. High-temperature and high-pressure water was evaluated for removing the binder from the asphalt mixture and recovering the aggregate. The study found that high-temperature and high-pressure water could remove the binder, particularly in the supercritical region, and that water was effective for removing binder and recovering aggregate from Type II modified asphalt as well as straight asphalt. Further removal of the remaining binder was achieved by repeating the tests in the sub-critical region where adequate effects were not achieved in a single test, suggesting the potential for an iterative approach under low-temperature and low-pressure conditions that would be more suited to commercialization. The present high-temperature and high-pressure water method of separation and reclaiming technology can recover and recycle valuable natural aggregate and oil resources from asphalt pavement waste.