Research On Applicability Of50#Hard Asphalt In Asphalt Bottom Layer Of Drought Alpine Region

With the deepening of China’s western development strategy, traffic and overloadingof vehicles of drought alpine region such as Qinghai province are increasing, Poor naturalconditions and the increasing traffic load badly damage asphalt pavement of the droughtalpine region, which impacts local transportation and restricts the economic development.Therefore，it is significant to study the applicability of50#hard asphalt which has goodperformance of high temperature rutting resistance and low price in asphalt bottom layer ofdrought alpine region.To obtain the design emphasis of asphalt mixture pavement performance of droughtalpine region pavement, collect the climate data of drought alpine region of QinghaiProvince and investigate the pavement disease of national road G215line. From asphaltcomposition, high temperature performance and low temperature crack resistance aspects,through four components test, the conventional asphalt test, DSR and BBR test, study the50#asphalt binder and its mortar systematically, and recommend filler-bitumen ratio range.On the basis of asphalt and asphalt mortar research, follow the principle that optimizinglow temperature crack resistance on the premise of meeting the high temperature stability,to design material composition of asphalt mixture. Moreover, make comparative study ofthe effect on50#asphalt mixture low temperature crack resistance made by differentgradation, asphalt content and temperature, and modify50#asphalt mixture design methodin drought alpine region, increase the low temperature bending strain energy thresholdindicator. Finally conclude that50#asphalt applies to asphalt bottom layer of droughtalpine region, summarize the design principle and process of50#hard asphalt mixture indrought alpine region, recommend the range of each index of the mixture design method.