Fatigue Properties Of Epoxy Asphalt Composites

In this paper,the epoxy asphalt composites required for the experiment were prepared and their tensile properties were tested.The results show that the self-made epoxy asphalts have good mechanical properties.The linear viscoelastic regions(LVE)of epoxy asphalts at different temperatures and frequencies were tested by dynamic shear rheometer(DSR).The results demonstrate that LVEs of epoxy asphalts decrease with the increase of test temperatures and the decrease of modulus.At a certain loading frequency,the modulus of the self-made epoxy asphalts increase with frequency,especially at high temperatures.The effect of different loading stress on the fatigue properties of epoxy asphalt used in the experiment was studied by using DSR,and the mechanical properties of epoxy asphalts after fatigue tests were observed by temperature sweeps.The results illustrate that the epoxy asphalt is continuously loaded with the loading stress within LVE.The macro-structure of the epoxy asphalts will not be broken down quickly,and the increase of modulus is caused by the stress-induced cross-linking reaction.The results of temperature scanning show that the mechanical properties of epoxy asphalts after stress loading are improved compared with the control samples,especially at high temperatures.With loading stress increasing,the maximum peaks of the loss factors tan? become sharper,indicating that the larger the loading stress imposed,more uniform the distribution of epoxy asphalt do,in a certain stress range.The effects of different loading temperatures on fatigue properties of epoxy asphalts used in the experiments and their mechanical properties before and after loadings were compared by temperature scanning experiments.The results show that when the temperatures are greater than 30?,the quick failure of the epoxy asphalt is caused by the continuous loading force higher than the critical LVE stress.However,when the temperatures are lower than 30?,the higher the loading temperature are,the bigger moduli exhibit,and no evident fatigue failure was observed in the experimental time,which is raised from the stress-induced cross-linking reaction.When the stress is within LVE,the results show that the lower the loading temperature,the higher the moduli are.When the loading temperature reached 80?,the epoxy asphalt still was not damaged by fatigue.The temperature scan results show that epoxy asphalts' high temperature performances will become better with temperature increasing.In this paper,the effects of different loading frequency on the fatigue properties of epoxy asphalts were studied by DSR.The mechanical properties of epoxy asphalts were observed by temperature scanning.The results show that the moduli of the epoxy asphalts increased with frequency,which is also caused by the cross-linking reaction induced by continuous loading stress.Therefore,it can be observed that under the condition that the loading stress is fixed,with the increase of loading cycles,from the beginning to the end of the load,epoxy asphalt has never been fatigue damaged;through the temperature scanning experiments,the results show that the epoxy asphalt performance has improved under the different loading frequency in a certain range.