Study On The Performance Of Hot In-place Reclaimed Asphalt Pavement At Low Temperature

Recent years, highway construction in China has been stepped into a period when the requirement of repair is as important as the construction. The hot in-place recycling technology has been used widely because of its convenience and practicality. Aging pavement always has stronger stiffness, which is unfavorable to the quatity of pavement at low tempertature and this factor is often ignored. So it is necessary to study on the performance of hot in-place reclaimed asphalt pavement at low temperature.The study is based on the hot in-place recycling project of highway G102, from K643 to K648. In this project, the percent of old materials was set at 80% and two kinds of percents 100% and 60% also be considered to make Comparation. Because of the performance of asphalt mixture at low temperatures is largely affected by the asphalt, both of them have been examined. Both common indexes and SHRP indexes of the asphalts have been tested, and their grey correlation was obtained. Based on the BBR test, creep regulation of the reclaimed asphalt was obtained. Beam bend test was carried out for the asphalt mixture, got the regular of destroy load, destroy deform, modulus and curvature strain energy.It has been approved that the performance of reclaimed asphalt and asphalt mixture at low temperatures are much better than the old ones. For the reclaimed asphalt, penetration degree and ductility at low temperatures increase, while equivalent brittle point and penetration index decreases, creep stiffness comes down and creep velocity increases. For the reclaimed asphalt mixture, all of destroy load, destroy deform and curvature strain energy increase. With the percent of old materials decreases, all the indexes are improved, but the ratio of improvement becomes smaller.