| Epoxy asphalt is composed of matrix asphalt, epoxy resin, curing agent and other additives, which possesses the advantages of high strength, fatigue resistance and stable pavement performance. However, compared with other types of asphalt, epoxy asphalt mixture produces higher temperature stress in low temperature. Therefore, it is necessary to improve the flexibility and low-temperature performance of epoxy asphalt through certain technical means.Firstly, through the comparative study on toughening technology of epoxy resin, three kinds of epoxy asphalt are prepared by introducing flexible chain segments with different number average molecular weight. Then self-made epoxy asphalt mixture is designed, and its low-temperature performance was evaluated through beam bending tests. The results show that, those tested beams with higher number average molecular weight of the flexible chain segment have relatively lower failure load, and their low-temperature deformation ability is accordingly stronger.Secondly, the creep tests are conducted to self-made epoxy asphalt and domestic epoxy asphalt. By comparing different creep rates and creep compliance with each other, the paper analyses the viscoelastic characteristics of self-made epoxy asphalt under low-temperature.Thirdly, the Burgers model and the fractional derivative Kelvin model of the self-made epoxy asphalt mixture and domestic asphalt mixture are constructed. Then the creep compliance master curves are fitted by the two models above. As results, the viscoelastic model parameters are obtained by nonlinear regression, and the fitting of the two models are also analyzed.Finally, creep compliance master curves of self-made epoxy asphalt mixture and domestic epoxy asphalt mixture are obtained according to the time-temperature equivalency and W.L.F equation, and then the temperature stress of the two kinds of epoxy asphalt mixture during the cooling process is analyzed. Results show that under the same temperature, the epoxy mixture with larger number average molecular weight of the flexible chain segment possesses the lower temperature stress. |
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