| The bonding performance of the asphalt-aggregate interface is an important guarantee for the structural stability of the asphalt mixture.The asphalt-aggregate interface as a weak link in the asphalt mixture exhibits different bonding strengths due to the influence of the material characteristics.The weak bond at the asphalt-aggregate interface is most prone to failure,which seriously affects the durability of the asphalt pavement under the action of moisture induction and external force.Based on previous research results and in order to further explore the influence of material properties on the bonding performance of the asphalt-aggregate interface,this paper starts with the analysis of the bond strength and failure surface of the asphalt-aggregate interface under different moisture conditioning times.The correlation between the adhesion failure area rate and the bonding performance of the asphalt-aggregate interface was established by quantifying the failure surface.Secondly,based on the test results of asphalt binder properties and aggregate properties,the effects of different material properties on the bonding performance of the asphalt-aggregate interface under wet conditions were quantified by means of data statistical methods and correlation analysis methods.The conclusions of this paper are as follows:(1)The adhesion strength of the asphalt-aggregate interface is greater than that of the asphalt strength,and the failure form of the asphalt-aggregate interface is cohesive failure under dry conditions.The combination of SBSMA with aggregate and the combination of limestone with asphalt binder show higher bond strength than other combinations.Continuous moisture regulation will cause the failure mode of the asphalt-aggregate interface to change from cohesive failure to adhesion failure.The time point when the failure mode starts to change can be used to characterize the moisture sensitivity of the asphalt-aggregate interface.(2)Asphalt binder with low penetration,high softening point has better bonding properties.The increase in resin content is beneficial to the moisture resistance of the asphalt-aggregate interface.The increase of aromatic and saturated content will weaken the interaction between the polar compound and the aggregate in the asphalt-aggregate interface.Asphalt binder contains more branched-chain structure compounds is more sensitive to moisture than asphalt binder with more long-chain structured compounds.Aggregates with high water absorption rate and high alkali value will have greater interfacial adhesion when combined with asphalt binder.The presence of Ca in the aggregate is beneficial to maintain the bonding properties of the asphalt-aggregate interface in moisture,and the presence of Si will promote the moisture destruction of the asphalt-aggregate interface.(3)Based on the results of the limited data points and the Pearson correlation coefficient between each factor and the increase in adhesion failure.The mechanical interlocking formed by asphalt binder on the surface of aggregate has better resistance to moisture erosion than the chemical adsorption formed by asphalt binder and aggregate at the asphalt-aggregate interface.The effect of material properties on the moisture resistance of the asphalt-aggregate interface is in the following order: Aggregate macro index > Aggregate micro index > Asphalt binder micro index > Asphalt binder macro index. |
PDF Full Text Request