Study On High And Low Temperature Performance Index Of Polymer Modified Asphalt

As a typical viscoelastic material,asphalt has different physical properties at different temperatures.Therefore,the performance characteristics of asphalt pavement at different temperatures are the research hotspot in the field of road building materials.At present,the research on the performance of asphalt binder is mainly based on the evaluation method of viscosity grade based on SHRP system.With the development of modified asphalt,especially polymer modified asphalt,whether the research results in 1980s are suitable for contemporary asphalt materials is worth further discussion.Based on four types of polymer modified asphalt,the performance of asphalt binder was evaluated by traditional physical test,rheological parameters test and non-Newtonian fluid mechanics theory,a series of performance parameters such as softening point,rotational viscosity,PG grade,zero shear viscosity,toughness and glass transition temperature were obtained.Further more,high temperature Marshall test,rutting test,low temperature bending test and low temperature splitting test were carried out on the mixture either.In addition,combined with the grey relational analysis theory,the correlation between the performance index of asphalt binder and the actual performance of asphalt was analyzed.Eight asphalt high temperature performance indicators and nine low temperature performance indicators were used as comparison series.Dynamic Stability（DS）and Bending Strain Energy Density（BSED）of Mixture as reference series.Grey relational analysis and calculation are carried out,The degree of correlation between each factor and the reference sequence is given in the form of relevance degree.The results show that for four types of polymer modified asphalt,Zero shear viscosity（ZSV）obtained by fitting curve with Cross/Sybilski formula has higher correlation with asphalt actual high temperature performance than PG high temperature grade.Unrecoverable creep compliance(J_nr)can distinguish the performance of asphalt significantly when it is used to characterize the high temperature deformation capacity of asphalt.However,conventional indexes such as softening point do not fit the actual performance of the mixture well.In addition,the glass transition temperature,low temperature rheological properties and low temperature mechanical ductility test of polymer modified asphalt have good correlation with the low temperature bending test results of asphalt mixture.Glass transition temperature has the highest relevance degree,which can better reflect the low temperature performance of polymer modified asphalt,followed by Low Temperature Rheological index and asphalt toughness.