Study On The Application Of 70~# Asphalt In Seasonal Frozen Highway Engineering

No.90 heavy traffic paving asphalt is widely used in highway asphalt pavements in seasonally frozen regions, but it is difficult for No.90 Asphalt mixtures to meet the demand of high temperature stability in great traffic conditions, and as a result, serious rutting disease occurred. It is surveyed through core tests and related research that the maximum shear stress under heavy vehicle load is usually located in the medium and lower layers of pavement, approximately 4-9 centimetres below road surface. Due to insufficient high temperature deformation resistance of No.90 heavy traffic paving asphalt, there occurred large deformation in medium and lower layers of pavement at higher temperature and shear stress and resulted in serious rutting disease. In this project No.70 heavy traffic paving asphalt is planned to be used in the medium and lower layers of pavement in seasonal frozen regions in order to improve the high temperature rutting resistance of pavement.During the research program, through highway condition investigation and diseases forms and reasons analysis for No.70 heavy traffic asphalt highway in Jilin Province, the applicability and application conditions of No.70 heavy traffic asphalt used in medium and lower layers of pavement has been preliminary controlled.Through indoor test comparison of 70 asphalt,70 asphalt mastics and 70# asphalt mixtures, high and low temperature performance level of No.70 heavy traffic asphalt has been proposed. Based on the climate characteristics and traffic composition, application layers and pavement structures for No.70 heavy traffic asphalt at different frozen regions are proposed. Mechanical analysis of proposed pavement structures has been carried out by Shell pavement calculation program, test roads have been paved to verify the rationality of pavement structures. At the same time, construction technology and application guide for No.70 heavy traffic asphalt pavement have been summed up.This project focused on enhancing asphalt pavement rutting resistance with no increase in project cost in seasonally frozen regions to improve the highway operation quality and extend service life, therefore it has a certain application value.