Investigation on patching failure of steel bridge deck pavement on the mesoscopic scale.

• Investigation of the mechanical response of asphalt concrete patch structures at the meso -level. • Exploring the behavior mechanism of new and old asphalt concrete cracking after pothole patch through three-point bending test. • Simulation of viscoelasticity of asphalt mortar with cohesive units with a thickness of zero. • Analysis of the effect of aggregate and mortar on patching structural damage through simulation. Pothole is one of the most serious distresses of steel bridge deck pavement (SBDP). Due to the particular structural condition, severe environment, and heavy traffic load, patch failure has become very common in SBDP. To investigate the effects of different patch materials on the patched structures, this paper explored the behavioral mechanisms of new and old asphalt concrete cracking after pothole patching and the effects of the different types of patch materials through three-point bending (3 PB) tests and finite element (FE) simulation at the meso -level. The results show that changes in aggregate modulus, asphalt mortar modulus, and asphalt mortar bond strength affect the flexural-tensile property and crack location. Cracks are more likely to occur on the side with less asphalt mortar bond strength. When the mortar bond strength of patch material is much greater than that of old asphalt concrete, flexural-tensile strength will be improved, and the effect of the internal bond strength of the mortar is much more significant than that of the bond strength between the mortar and the aggregate. To improve flexural-tensile strength, priority should be given to changing the mortar modulus and its bond strength. [ABSTRACT FROM AUTHOR]