ABSTRACT
Reinforced concrete (RC) bridge deck slabs in cold regions are simultaneously subjected to freeze–thaw cycles (FTC) and fatigue loading, leading to premature deterioration. However, this issue is rarely considered in their design. This study employed multi-scale numerical simulations to investigate the fatigue performance of frost-damaged RC slabs. The proposed model was validated against experimental results, which successfully reproduced the coupled deterioration process involving pore ice pressure and wet fatigue. Based on the validated model, parametric analyses were performed to examine the influences of the water-to-cement (W/C) ratio, air content, and freezing temperature on the fatigue life of RC slabs. The results show the quantitative effects of a W/C ratio decrease, an air content increase, and a freezing temperature increase on the fatigue life of RC slabs. Meanwhile, inadequate concrete quality may cause severe damage under FTC. Finally, a strain energy-based damage factor, https://www.w3.org/1998/Math/MathML" display="inline">KU, is proposed to quantify material degradation under combined environmental and mechanical actions. https://www.w3.org/1998/Math/MathML" display="inline">KU effectively captures the coupled deterioration mechanism and provides a rational and practical indicator for the durability assessment and maintenance management of RC bridge decks in cold climates.
