An Analysis on Mesoscopic Interfacial Damage of Semi-flexible Material at Different Temperature Ranges
Damage and cracking are vital affecting factors on structural durability and traffic safety.Semi-flexible material(SFM)for pavement is produced by pouring cement grouting material into the asphalt concrete skeleton.SFM exhibits both characteristics of cement and asphalt-based materials,advancing durability and driving comfort.It is recognized that the incompatible deformation of various phases of components mainly causes the interfacial damage of SFM.In order to reveal the interfacial damage in semi-flexible materials during temperature changes,the FEM is used to simulate the bonding to detachment process of the interface region in SFM at different temperature ranges by introducing a cohesive zone model(CZM).Firstly,the skeleton asphalt mixture of SFM is designed with a target porosity of 25％,after testing the primary performance,cement grouting material is poured to prepare SFM specimens.Further,the SFM's internal structural information is measured by CT,which is used to construct the mesoscopic FEM.The tests for temperature shrinkage behavior at different temperature ranges are conducted with SFM components,including open-graded asphalt mixture,cement grouting material and aggregate.The stress concentration,failure degree and damage distribution of the SFM interface are revealed by inputting the linear shrinkage coefficients and cohesive parameters into FEM.The result shows that(1)aligning with the ordinary working conditions,the internal stress generated by the cooling process from 20℃ to ―30℃ mainly concentrate in the aggregate-asphalt binder-cement grout interface region;(2)by analyzing the stress and damage degree of each cooling range,during the cooling range from 20℃ to 10℃,the asphalt film has the most minor bond strength and fracture energy while bearing the most extensive incompatible deformation,therefore,the SFM interface is prone to damage and cracks in this cooling range.
road engineeringinterfacial damageFEMsemi-flexible materialcohesive zone model(CZM)temperature range impact
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