Research On Development And Evaluation Method Of High Viscosity Modified Asphalt

High-viscosity modified asphalt is the core material of permeable asphalt pavement,but there are relatively few high-viscosities modified asphalt with good performance in domestic market at present,and there are relatively few studies on evaluation methods of high-viscosity modified asphalt performance.Therefore,it is particularly important to study the development and evaluation methods of high viscosity modified asphalt.In this paper,the influence of each component on the three major indexes and the 60°C dynamic viscosity was studied by the control variable method.Four kinds of self-made high viscosity modified asphalt of the same type were prepared according to different SBS structures and whether B（tackifier）was added.The following studies were carried out with matrix asphalt,Haichuan high viscosity and Japanese TPS high-viscosity asphalt:the microstructure was studied by microscope and infrared spectroscopy;the high temperature was evaluated by high temperature conventional index,60°C zero shear viscosity and multi-stress repeated creep.And the rationality of each evaluation method was analyzed;the 5℃ductility,equivalent brittle point T_1.2,P grading temperature,critical grading temperature T,comprehensive compliancewereused to evaluate the low temperature and the rationality of each evaluation method was analyzed;the temperature sensitive routine index and the low temperature rheological index were used.The dynamic shear rheological index and the viscosity-temperature curve were used to evaluate the temperature sensitivity and the rationality of each evaluation method was analyzed.The durability was evaluated by RTFOT,PAV,fatigue factor and LAS test,and the rationality of each evaluation method was analyzed.Four high-viscosity modified asphalts were selected to test the performance of high-viscosity modified asphalt and the accuracy of the evaluation method through the performance of porous asphalt mixture.Microscopic analysis showed that the polymer modifiers in the four self-made high viscosity modified asphalts were evenly dispersed,with good thermal stability and certain chemical modification.The performance analysis shows that the four self-made high viscosity modified asphalts have good high temperature,low temperature,temperature and durability,and are superior to Haichuan high viscosity and TPS,but the performance between the four self-made high viscosity modified asphalts There is a certain difference,because the SBS structure and B will have an impact on its performance.The analysis of the high viscosity modified asphalt evaluation method shows that the 60°C zero shear viscosity,multi-stress repeated creep evaluation of high temperature is reasonable,the critical classification temperature Tevaluation of low temperature is more reasonable,、GTS′、M（three indicators are temperature sensitive coefficients）evaluation of low,medium and high temperature range temperature sensitivity is more reasonable,LAS test evaluation fatigue performance is more reasonable.The performance of the porous asphalt mixture and its correlation with the asphalt index proved that the results were consistent with the asphalt index evaluation results.Considering performance and cost,this paper gives priority to HMA-2（linear SBS plus tackifier）for porous asphalt pavement.