Study On The Key Technologies Of The Recycled Asphalt Pavement

With the development of highway construction in China, the age has come when some highways that were constructed earlier are being maintained or reconstructed in succession. As a result of that, a mass of old asphalt mixture has been produced, which occupies vast expanses of land and causes pollution. To resolve the problem and economize on resources, research on asphalt recycling should be carried out immediately.At present, neither a mature evaluation mechanism nor grading standards for recycled aggregate have been developed in China. Moreover, the RAP (reclaimed asphalt pavement) has various sources and the asphalt pavement recycling equipment is far from advanced. So to control the quality of the recycled concrete becomes quite difficult and much risk exists in the application of recycling technology.Currently, the impact of the applicability of the regeneration methods and the variability of the RAP on the road performance has become a focus of attention in the field of asphalt pavement recycling.By analyzing the characteristics of different asphalt pavement recycling methods and their corresponding construction technologies and application scopes and at the same time taking into consideration the experience and results from relevant research at abroard, the paper discusses how to select the appropriate recycling methods for pavement reconstruction and puts forward the selection methods and the principles for the pavement recycling which go in concert with the present situation in China.To measure the impact of the variability of the recycled material on the regeneration effect, the author uses orthogonal experiment method to design the experiment. By using three original recycled materials of different service life spans, he prepares nine types of basic test materials which could meet the requirement of the orthogonal experiment. Then he conducts tests of road performance properties (such as high temperature stability, water stability, durability, etc) on these materials respectively and analyzes the three key factors (asphalt aging, asphalt content, aggregate gradation) that lead to performance variation of recycled material. At last he reaches a conclusion about the impact of these factors on the service property of the reclaimed asphalt mixture and proposes effective measures that could guarantee its quality stability by controlling the material source.