The Research On Shear Fatigue Experiment Of Asphalt Mixture At High Temperatures

Asphalt pavement is widely used in China.With the change of pavement structure of transportation, Asphalt pavement produce a number of new diseases,such as flow rutting and load cracks.These new diseases generally appear in the position of wheel tracks. According to the road scene investigation,it is found that the emergence of these diseases have a direct relationship with large shearing action on asphalt layer. However,the road shearing action is not as a control indicator in road design in our country.This paper studied the shear fatigue performance of asphalt mixture based on a great quantity of domestic and foreign data,the two main parts of this text are the laboratory experimental study and finite element analysis.Firstly.Superpave shear test(SST) and Simple performance test (SPT). were introduced to do laboratory experimental study.According to the RSCH research on three kinds of bituminous mixtures has been obtained the corresponding deformation curves which judge the shearing strain of asphalt mixtures.Using Semi logarithmic curve Good-fitting the shearing times and shearing strain.Through the FSCH test can obtain the Relationship between the experiment index(G*、8 and G*/sin8) and test frequency. And then,with comparative analysis the experiment index between RSCH and the dynamic modulus testing.The results show the the changing trend of the two index was accordant.Based on the multi-layer elastic system theory,the paper established model by analysis soft ABAQUS to calculate the shear stress and shearing strain of semi-rigid base asphalt pavement and flexible base asphalt pavement.The location of maximum shear stress is about 4cm below the pavement. The results showed that the trend of the two forms of pavement is same and the reasons causing Top-Down cracks is shear stress. Comparative the result obtained that the shearing strain of flexible base asphalt pavement is smaller than semi- rigid base asphalt pavement’s.