Study On Durability Of Recycled Asphalt Mixture In Northwest China

Road traffic is the cornerstone of a country's rapid development,China is about to complete the “two centenary strategic tasks” while completing the intelligent transportation construction planning.The concept of intelligent transportation is implemented from four aspects of comprehensive,smart,green and safe.The development of high grade asphalt pavement is the foundation of intelligent transportation,and the high grade asphalt pavement needs better pavement maintenance technology to improve its service life.In order to better implement the “national five pronged development strategy” and achieve the national concept of green and sustainable development,vigorously develop asphalt pavement maintenance and regeneration technology is greatly important.This thesis is based on further research of asphalt pavement mixture in northwest China,aims to develop more suitable aging asphalt regeneration agent for the northwest regions,combining the milled materials of centrifugal separation and vacuum extraction obtained the aged asphalt,and based on the optimal amount of regenerating agent obtained from previous projects.This paper used different upgrading products to study the regeneration performance of aged asphalt,Gel Permeation Chromatography(GPC),Fourier Transform infrared spectroscopy(FTIR)and Dynamic shear rheological test(DSR)were used to test the performance of recycled asphalt.The results show that the regenerating agent B with a content of 5% has better regeneration effect on the aged asphalt of the tested highway section.Based on the design of the reclaimed asphalt mixture and the analysis of gradation of milling and new materials,determined the milling material content is 30% and the synthesis gradation.A series of indoor tests were conducted to analysis the road use performance and durability of the reclaimed asphalt.From the water stability,high temperature stability and low temperature cracking resistance tests of the reclaimed asphalt,indicating that the addition of regenerating agent B has better regeneration effect on the aged asphalt in the tested section.The dynamic modulus and rheological properties of recycled asphalt mixture were characterized by UTM,the fatigue factor of regenerator B is much smaller than that of regenerator A,at medium temperature,and the rutting factor of regenerant B is also much smaller than that of regenerant A,at high temperature.From the perspective of durability,the reclaimed asphalt mixture with regenerant B has better durability.By taking field samples of roads in northwest China,the regeneration mechanism of the reclaimed asphalt was analyzed by adding regenerant and sampling aged asphalt.Combining with the road performance research and durability analysis of the reclaimed asphalt,indicating that the road performance of aged asphalt can be effectively recovered by adding regenerant B and improves the durability of the the reclaimed asphalt mixture.In the future,the intelligent traffic system will have higher standards for the construction of high-grade asphalt pavement,the road maintenance and regeneration technology.Therefore,it is very important to improve the durability of asphalt pavement and its evaluation criteria standards...