Research On The Pavement Performance Of Asphalt And Its Mixture Modified By High Modulus Additive

With the rapid development of China’s transportation industry,the construction of transportation infrastructure is also developing simultaneously,and the road,as the artery of the transportation industry,has been put forward more requirements.Asphalt as a kind of high quality road material is also more and more widely used in the pavement construction,asphalt pavement has become the most important pavement.However,with the widely use of asphalt in the highway,due to temperature changes,rain,snow and other reasons,many problems are increasingly prominent,cracking,rutting and spalling and other diseases emerge in an endless stream,seriously affecting the normal use of the road,causing loss of life and property.In order to meet the demand for road service level,all kinds of new materials are appearing,and high modulus additive is one of them.As a kind of asphalt additive,high modulus additive has the characteristics of high tensile resistance,high liquidity and high modulus,etc.It is a kind of high quality asphalt additive.In this paper,high modulus modified asphalt is prepared by adding PR,Baoli and Haichuan three kinds of high modulus additive in asphalt,then research the road performance of high modulus asphalt mixture by experiment.The main research results are as follows:(1)Nine kinds of high modulus agent modified asphalt were prepared in the case of high modulus agent dosage of 3%,6% and 9%.The basic properties of asphalt modified with high modulus agent were studied,the softening point has been greatly improved,the penetration degree decreases with the increase of high modulus agent content,the ductility is greatly reduced;(2)The high temperature rheological properties and multi-stress creep recovery properties of nine kinds of high modulus agents modified asphalt were studied.The results show that the high temperature rheological properties and multi-stress creep recovery properties of asphalt are greatly improved after the addition of high modulus agents.According to the high temperature properties,the optimal dosage of three kinds of high modulus agents are 9%,3% and 6%,respectively;(3)The asphalt mixture ratio test was carried out under the optimum dosage of three kinds of high modulus agents to determine the mixture grade and the best asphalt to stone ratio;(4)Through the road performance test of high modulus asphalt mixture and the Semi-circular Bending Test(SCB),the road performance of high modulus asphalt mixture is studied,and the resistance ability of asphalt mixture to crack propagation after cracking is evaluated.The results show that the high temperature stability,water stability and dynamic modulus of the high modulus asphalt mixture are improved obviously,the low temperature crack resistance is basically unchanged,and the crack propagation performance is also improved to a certain extent.Through the research in this paper,the performance of high modulus modified asphalt and its mixture has a deeper understanding,for the use and promotion of high modulus additive to provide experimental and data basis,but also to provide support for designing high temperature and heavy load pavement.