Study on the Rheological Properties of Gussasphalt after Superheat Aging

Gussasphalt mixture has many excellent characteristics such as imperviousness, strong integrity and good flexibility. In recent years, it has been widely used in large and medium-sized bridges, especially steel bridge deck pavements. However, unlike ordinary mixed materials, gussasphalt needs to undergo long-term high temperature aging during mixing and transportation. In order to deeply explore the superheat aging mechanism of gussasphalt, dynamic shear test and bending beam rheological test were mainly used to study the effect of different superheat aging conditions on the high and low temperature rheological properties of gussasphalt in this paper. The test results show that the complex modulus G* of the gussasphalt after aging at 240 °C, 220 °C and 200°C for 6h is 3.6, 3.4 and 2.1 times of 163 °C aging respectively at the test temperature of 48 °C. The low-temperature stiffness modulus of gussasphalt shows an increasing trend, while the creep rate shows a decreasing trend, which indicates that the ability to resist low-temperature cracking for gussasphalt is getting worse after higher temperature aging.