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. Hightemperature 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.

The recycling ratio of reclaimed asphalt pavement (RAP) reached about 99% in 2002, the highest for any industrial waste, a clear sign that recycling efforts are actively applied in the road pavement fi eld. Even more effective use of resources and materials will require the incorporation of environmentally-friendly processes over the entire cycle. It is also necessary to establish a pavement recycling system that can cope with the diversifi cation of pavement materials and reclaimed materials, such as modifi ed reclaimed materials, of which production of which is predicted to increase. This study proposes a pavement recycling technique in which high-temperature and high-pressure water is used to separate and recover aggregate and asphalt binders in RAP for reuse. The removal performance of two types of deteriorated asphalt binders was evaluated. The properties and quality of separated and recovered aggregate were also tested to examine the suitability of the recovered aggregate as pavement. The tests and analyses showed that high-temperature and high-pressure water was very effective for removing deteriorated binders and modifi ed binders. High-temperature and high-pressure water is an environmentally friendly recycling technique with great potential and repeated reuse of recovered aggregate is feasible.

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The aim of this research was to develop an improved recycled asphalt pavement by using reinforcement sheeting to decrease the shortcomings of reclaimed asphalt pavement (RAP), and take advantage of its merits. Evaluation tests showed that the use of reinforcement sheeting in combination with recycled asphalt mixture r esulted in a paving material that significantly outperforms virgin asphalt mixture in rutting resistance, crack resistance and serviceability. Concern for the state of the environment has grown considerably in recent years throughout the world. Road construction is no exception to this. This report was submitted in the hope that the proposals it contains would contribute to further promotion and expansion of effective use of recycled asphalt mixture.

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