Evaluation Research On High Temperature Performance For Asphalt Mixture Of RIOHTrack Based On SPT

Currently,there are variety of tests and indexes for evaluating high temperature performance of asphalt mixture at home and abroad.However,the evaluation results tend to be more different due to the disparity of test conditions,models,and indexes.It is very necessary to standardize the methods in order to evaluate the high temperature performance of asphalt mixture objectively.Therefore,relying on the 23 kinds of asphalt mixtures used in RIOHTrack of full-scale test circular track in Research Institute of Highway Ministry of Transport,a research on high temperature performance was carried out by complex modulus test of Simple Performance Test(SPT),repeated load test of SPT and French Rutting Test(FRT)to seek the reliable evaluation methods and suitable test evaluation indexes,and select asphalt mixture types with excellent high temperature performance.(1)The complex modulus and its master curve were analyzed through the complex modulus test of SPT,the results show that the complex modulus is significantly affected by the temperature,frequency and strain level.The complex modulus ?E*| and anti-rut factor |E*|/sin? can reflect the high temperature performance of asphalt mixture effectively.The results of repeated load test of SPT show that the deformation development of the mixture becomes faster with the increases of temperature and deviator stress,and alleviate with the increases of confining pressure;FN,?p/FN and c can be recommended as the evaluating indexes for high temperature performance of asphalt mixture.Combined with the rutting results of FRT,it's found that several different methods all evaluate the high temperature performance of asphalt mixture commendably,but there exist some differences.(2)Several test results all indicate that the high temperature performance of asphalt mixture are significantly affected by the factors such as asphalt type,additives,and gradation etc.All the low grade base asphalt mixture,SBS modified asphalt mixture,rubber asphalt mixture and asphalt mixture of anti-rutting agent content of 0.8%have excellent high temperature performance,and the recycled asphalt mixture is well.The high temperature performance of base asphalt mixture increases with the decrease of the grade of base asphalt.The SMA with skeletal dense structure has excellent high temperature performance while the porous asphalt mixture relatively poor.(3)The results of correlation analysis between different indexes of the same test method show that there are significant correlation between |E*| and |E*|/sin?,FN,?p/FN and c.|E*|/sin? and FN can be slected as the evaluation indexes of high temperature performance test in complex modulus test and repeated load test of SPT respectively.FN has high determination coefficient with other indexes and the weighted average value is the biggest.Therefore,it is recommended to select the repeated load test of SPT and FN as the optimization evaluation method and evaluation index of high temperature performance of asphalt mixture respectively.Finally,the tested data of rutting of the RIOHTrack asphalt pavement were analyzed,and the results are generally consistent with the indoor tests.In summary,the results in this thesis can provide a scientific reference for the rational evaluation of high temperature performance of asphalt mixture.