Effect of high viscosity modifier on rheological properties and microstructure of high viscosity asphalt

Abstract

High viscosity asphalt is widely used in drainage pavement due to its excellent high and low temperature performance. The rheological properties and microstructure of high viscosity asphalt were studied by frequency scanning, temperature scanning, steady flow test and fluorescence microscopic observation. The results showed that in the range of test frequency and temperature, the loss modulus G” of high viscosity asphalt is larger than that of storage modulus G’, and with the increase of the amount of high viscosity modifier, the storage modulus G’, loss modulus G” and rutting factor G*/sin δ of high viscosity asphalt increase, and the difference between G’ and G” decreases. Moreover, the addition of high viscosity modifier led to the appearance of shear thinning phenomenon, with the increase of the amount of high viscosity modifier, the degree of deviation from Newtonian fluid of high viscosity asphalt increased, and the zero shear viscosity η0 is significantly increased at 60°C. There was a linear correlation between the amount of high viscosity modifier and log(ω1.0), failure temperature and log(η0,60°C) of high viscosity asphalt. The high viscosity modifier was dispersed in the asphalt as a ball, the dosage of the high viscosity modifier increased, on the other hand, the particle size of the high viscosity modifier became smaller and the dispersion was denser.