Study On Modification Mechanism And Road Performance Of High Modulus Composite Modified Asphalt Mixture

With the rapid development of China’s economy,the traffic volume is increasing day by day.Asphalt mixture for it as a comprehensive road surface has the very good performance,has been applied in wide areas in China,but due to regional differences in climate geological conditions there will be a different form of pavement damage,the main disease forms forrutting and cold cracking,pavement diseases can reduce the use of the pavement performance,influence the quality of driving,more serious endangers safety.This study based on the high modulus asphalt mixture application base in north China,in liaoning province for the asphalt mixture pavement usage survey,with 0%,2%,3%,4% dosage of SBR with 0%,10%,20%,30% high modulus agent for compound preparation prepared composite modified asphalt,the compound modified asphalt penetration experiment,softening point,ductility test,and through the scanning electron microscopy test and DSC spectra method for composite modification mechanism analysis,the results show that high modulus agent increased can significantly improve the high-temperature stability of asphalt content;SBR has only a slight effect on the high temperature performance of asphalt and a significant improvement on the low temperature performance.From the microscopic perspective,it is found that SBR modifier is evenly distributed in asphalt and does not react with asphalt.There is no interference between the two polymer modifiers.SBR and high-modulus admixture can give full play to their own advantages.Considering the feasibility of economy and construction comprehensively,the dosage of high modulus agent should be controlled at about 20% and the dosage of SBR between 3% and 4%.Using high modulus agent in the preparation of SBR modified asphalt,high modulus of composite modified asphalt mixture by rutting test,low-temperature bending test and freezethaw splitting test to study the high modulus of composite modified asphalt mixture of high and low temperature performance and water stability,and the SBS modified asphalt,SBR modified asphalt mixture,high modulus of asphalt mixture,the matrix asphalt mixture performance comparison,the test results show that high modulus of composite modified asphalt mixture at high and low temperature performance and water stability,good performance,comprehensive performance is better than a single modifier preparation of asphalt mixture.The test sections of shensui line and shensui ring line were paved,and the test specimens prepared by asphalt mixture in the test section were compared with the data in the laboratory test phase.The test results of the two sections all met the requirements of the code,proving the construction feasibility and practical engineering value of high-modulus composite modified asphalt mixture.When the high modulus admixture is 3‰ of the asphalt mixture,the high temperature performance can still reach the 5000 times/mm or more required by the Liaoning provincial code.Considering the economic benefit and the asphalt mixture performance,it is determined that the high modulus admixture is 3‰ and the SBR modifier is 4%.