Research And Application Of High Temperature Stability Of Asphalt Mixture Under High Temperature And Heavy Load

The development of urban roads leads to the increasing traffic flow,channelized traffic effect is more and more obvious,and rutting disease of asphalt pavement has become an unavoidable problem.Due to the particularity of urban roads,its disease phenomenon is more likely to occur and more serious than that of ordinary road sections: Rutting disease is widespread in the urban road traffic,which are affected by many unfavorable factors such as many plane intersections,heavy load,overload and low speed driving.When the high temperature lasts,the rutting forms and develops rapidly.It is urgent to study the influencing factors and optimization measures of rutting disease in asphalt pavement.Taking the rutting disease of urban roads in Kunshan area as an example,based on field investigation and analysis of core samples,it is found that the gradation of asphalt mixture and the lack of angularity of aggregate particles are the main causes of rutting disease.this paper firstly analyses the gradation and the angularity of aggregate particles.Considering the effect of skeleton structure,for high temperature performance of upper layer two gradations,SMA-13 and SUP-13,are selected to study.According to the median value of gradation,the gradation curve is floated up and down,and three groups of gradations with different coarse aggregate content are obtained.Two different angularities are selected for each group of gradation.Xray CT scanning technology was used to analyze the morphological characteristics of the two kinds of aggregates.Finally,the relationship between aggregate angularity and skeleton structure of asphalt mixture is established.Secondly,in order to study the influence of gradation and aggregate angularity on pavement performance of asphalt mixtures,12 groups of asphalt mixtures were designed for uniaxial penetration test and rutting test respectively.Based on the test results,the sensitivity of gradation and aggregate angularity to high temperature performance of mixtures was analyzed.The test results show that both gradations have good shear resistance,and the effect of Aggregate Angularity on high temperature performance of asphalt mixture is significant.Thirdly,in order to study the shear rheological behavior of asphalt pavement,two kinds of aggregates with the best shear and high temperature performance are selected to carry out uniaxial dynamic creep tests,and the permanent strain of four groups of mixtures under load is analyzed.Based on the test data,combined with Burgers model,ABAQUS finite element software is used to analyze the permanent deformation law of the four different surface layers of pavement structure.Finally,aiming at improving the rutting resistance of asphalt pavement in Kunshan area,according to the results of field investigation and core sample analysis,combined with the data results of laboratory test and finite element calculation,optimizing the high temperature performance of top asphalt mixture by adding anti-rutting agent,gradation design of asphalt mixtures of various surface layers is carried out and corresponding measures to improve the high temperature performance are taken,and the composite structure of high temperature asphalt pavement is studied and optimized,In view of the rutting pavement in Kunshan area,the corresponding prevention and control measures are put forward.Finally,it is applied to a specific road for verification.