Mechanical Evolutionary Behavior of Steam‐cured Concrete under the Coupling Effect of Flexural Fatigue and Minus Temperature

AbstractSteam‐cured concrete products have been widely employed in building slab ballastless track for China High‐Speed Railway lines, such as track sleeper and track slab. These components are usually subjected to long‐term fatigue load due to the wheel‐rail interactions by high‐speed trains. Especially in Northeast China where the winter temperature keeps subzero for months, the concrete elements are exposed to the coupling effects of fatigue load and minus temperature environment. Therefore, this paper investigated the mechanical damage evolutionary behavior of steam‐cured concrete under coupling effects of flexural fatigue loading and minus temperature. Additionally, the mechanism behind it was discussed. The results showed that the mechanical damage of steam‐cured concrete subjected to fatigue loading under minus temperature was more significant than that under room temperature. The influences of ice content on the degradation in mechanical properties of steam‐cured concrete are illustrated by the phenomenological model. A two‐stage statistical damage variable can well reveal the impact of fatigue cycles and temperature on fatigue damage and total damage concrete. Steam‐cured concrete based on PC‐FA‐GGBS binder system exhibits better resistance to the flexural fatigue loading and minus temperature coupling effects due to its better pore structure and less ice content.