01624299

Component

The adhesive properties of asphalt-aggregate interface affect failure behaviors of asphalt mixtures. The objective of this study was to explore shear failure characteristics of asphalt-aggregate interface by researching the interface shear strength and the whole shear fracture process. First, the oblique shear tests were conducted to investigate the interface shear strength under the influences of surface roughness, binder aging, loading rate and aggregate type. Second, the direct shear tests were implemented to determine the interface failure process in terms of load-displacement characteristic curves. Finally, the bond-slip constitutive model of asphalt-aggregate interface was established from a generalized multiline cohesive zone model. The results indicate that the improvement of surface roughness and loading rate could induce higher interface shear strength and a basalt aggregate with less silica has greater resistance to interface shear damage than a granite aggregate due to its stronger adhesion to binder. The interface shear resistance energy could benefit from higher surface roughness and normal stress level. Although binder aging could increase the interface shear strength, it imposes an adverse impact on the interface shear resistance energy. The established bond-slip constitutive model of asphalt-aggregate interface could represent a three-stage evolution process of the interface shear failure, in which the shear strength ratio seems more sensitive to surface roughness and the shear residual displacement ratio is mainly affected by normal stress. The findings would throw a light on shear failure characteristics of asphalt-aggregate interface and provide support for further analysis on meso-mechanical behaviors of asphalt mixtures.

This paper was sponsored by TRB committee AFK50 Standing Committee on Structural Requirements of Asphalt Mixtures. Alternate title: Meso-scale Analysis on Shear Fracture Properties of Asphalt-Aggregate Interface.

01618707

17-02874

English

14p

2017

Transportation Research Board 96th Annual Meeting

Digital/other

Figures; Photos; References; Tables

Asphalt mixtures; Basalt coarse aggregates; Bond strength (Materials); Shear strength; Shear tests

Asphalt-aggregate interface; Bond slip; Load-displacement curves; Mesoscale; Shear failure

Highways; Materials; Pavements

Transportation Research Board Annual Meeting 2017 Paper #17-02874

TRIS, TRB, ATRI

Dec 8 2016 11:04AM