Effect of graphene oxide and polyphosphoric acid composite modifier on self-healing performance of asphalt
In order to study the effect of graphite oxide(GO)and polyphosphoric acid(PPA)composite modifier on the self-healing performance of asphalt,the molecular models of matrix asphalt and modified asphalt were established by Materials Studio software.The asphalt model was verified by density,solubility and glass transition temperature,and a vacuum layer of 1 nm was inserted between the two groups of asphalt to represent the micro-cracks after fatigue damage.The self-healing process of matrix asphalt and GO/PPA modified asphalt at different temperatures was studied,and the self-healing ability of both asphalt and GO/PPA modified asphalt was evaluated by the mean square displacement,diffusion coefficient,activation energy and pre-exponential factor.Finally,the accuracy of the simulation results was verified by rheological test.The results show that micro-cracks in matrix asphalt and GO/PPA modified asphalt can be repaired more quickly with the increase of temperature,and the diffusion coefficient of GO/PPA modi-fied asphalt is higher than that of matrix asphalt,indicating a higher self-healing efficiency.The research results are helpful to deepen the understanding of the self-healing effect of GO/PPA composite modifier and provide a theoretical basis for the follow-up similar research.
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