| With the development of freeway construction in our country, some freeways that constructed earlier should be maintained or reconstructed in succession. As a result, a mass of old asphalt mixture was produced. To take advantage of the reclaimed asphalt pavement (RAP) that would occupy vast expanses of land and cause polluting, the research of asphalt recycling should be carried out immediately.Combined with the Project of West Traffic Construction"the research of key technique on asphalt recycling", the hot central plant recycling technique was studied mainly in this paper. By reference to the design of common asphalt mixture, the paper gave the method of design on hot asphalt recycled mixture through the appraisal of RAP , synthetical grade of aggregate, recovery of asphalt aging, the determination of OAC and checkout of the design based on the overlay project within Zhuji section of No.22 province highway in Zhejiang.In order to certify that hot asphalt recycled mixture could be applied in surface course, a series of tests were carried out with the grades of AC-13 and AC-20 in different proportion of RAP. Through the wheel rutting test, immersion Marshall test, freeze-thaw split test, small beam bend test and sand patch test, it analyzed the high temperature stability, water stability, low temperature cracking resistance and pavement skid resistance of the hot asphalt recycled mixture. The study indicated that the performance of the high temperature stability would be improved while water stability and low temperature cracking resistance declined as the proportion of RAP increasing, but at low RAP contents the mixture properties were not significant different from that of mixtures with no RAP. The results showed that the performance of hot asphalt recycled mixture could meet all the requirements of specifications as long as appropriate proportion of RAP was mixed.It also analyzed the construction technique of hot asphalt recycled mixture and mixing equipment.
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