Study For High Temperature Rheological Properties Of Rubber Modified Asphalt

In recent years，with the rapid development of road traffic and auto industry，trafficsurge，the common damage of asphalt pavement such as high temperature deformationhave become one of the major problems of the road engineering field of research．Practicehas proved that the use of modified asphalt can effectively improve the high temperatureperformance of the asphalt， which can reduce the temperature damage of theasphalt．Therefore，the research about high temperature performance of the modifiedasphalt has become the focus of the study，but the modified asphalt and the matrix asphaltexist great differences in the nature，and at present a lot of evaluation standard is onlyapplicable to the matrix asphalt，it can not fully reflect the high temperature performanceof modified asphalt．So，the article is based on rheology theory and viscoelastic analysismethod，there are three kinds of modified asphalt：rubber powder modified asphalt，SBSmodified asphalt and the compound rubber powder modified asphalt，the main work is toanalyze high temperature rheological properties of the rubber powder modified asphalt bythe comparative analysis from the different aspects： modified asphalt microscopicstructure，thermal stability，heat resistance and rheological properties and so on．First of all，judging from the test results of scanning electron microscopy (SEM)，wecan learn that the modifier is mesh structure in three kinds of modified asphalt，and it hasbetter blending effect with asphalt．Through the DSC test we can find that three kinds ofmodified asphalt can exist steadily in the range of test temperature，which does not havethe change of state of aggregation，compared to the results，we can know that thecompound rubber powder modified asphalt and rubber powder modified asphalt havebetter thermal stability．Secondly, by using the penetration index PI、softening point and equivalent softeningpoint, we can analyze the temperature performance of modified asphalt. the index got fromrheological test methods contains penetration viscosity index PVN andviscosity-temperature index VTS, which can evaluate the thermal performance of modifiedasphalt, because penetration viscosity index PVN is got by calculating two temperature, ithas certain error when considering the whole temperature interval. Through the study onviscosity-temperature index VTS, we can find that viscosity-temperature index VTS can better reflect the heat performance of modified asphalt.Finally，by doing dynamic shear rheological test, the article mainly analyzes thechange rule of rheological parametersG ’、G "、、G、 G/sin with temperature andloading frequency，and through the optimization of the fight against the rut factorG/sin，the article analyze the rheological properties of three kinds of modified asphalt，and the results show that the rubber powder modified asphalt has good high temperaturedeformation ability．Through repeated creep experimental analyze the influence of creeprecovery for three kinds of modified asphalt at different temperature and stress level ofdifferent temperature and stress level，and the test analyze the delay of elastic deformationability of modified asphalt，the results show that the rubber powder modified asphalt hasbetter displacement restoring capacity．what′s more，we calculate the correspondingviscoelastic parameters based on viscoelastic model，we simulate the repeat creep recoverytest by using the finite element software ABAQUS to check the results of test，the resultsof simulation show that the results of test and that of simulation are close，judging from theresults of simulation，we can obviously learn the rubber powder modified asphaltviscoelastic has good delay elastic deformation，which can improve the displacementrestoring capacity of rubber powder modified asphalt．...