Interactive Effect of Mechanical Fatigue Load and the Fatigue Effect of Freeze-Thaw on Combined Damage of Concrete

Abstract

The combined attack of (1) mechanical fatigue load, and (2) freeze-thaw, can lead to premature deterioration of concrete materials in cold climate regions. The interactive effect of these two loads on the damage of concrete was studied numerically and experimentally. First, experiments were conducted for proof-of-concept of the numerical analysis. A numerical model was then constructed from the view that fatigue damage induces preferentially permeable concrete locally, which can lead to degraded stiffness by freeze-thaw effect and thus more fatigue damage. The numerical results demonstrated that the crack length decreased with the degree of freeze-thaw damage but the crack width, in contrast, increased. The experimental results agreed generally with the numerical results for more saturated conditions considering that the potential transport events of moisture and the heterogeneous microstructure should be included. The research reported in this paper sheds light on how mechanical load and environmental factors interact with each other in this complicated system to result in the ultimate failure of cement-based materials.