中文摘要：

海水寒冷地区的钢筋混凝土结构受到冻融循环与氯离子侵蚀的耦合作用，且混凝土结构通常是带裂缝工作。侵蚀与冻融循环容易造成钢筋与带有初始裂缝的混凝土之间的黏结性能退化。通过试验室模拟环境，对36个钢筋混凝土拔出试件经历300次冻融循环交替100次海水浸泡后，研究不同宽度初始横向裂缝和不同钢筋直径对钢筋与混凝土之间黏结性能的影响。结果表明，钢筋与混凝土的黏结强度随着初始裂缝宽度的增大而降低，且随着钢筋直径的增大而降低；随着钢筋直径加大，初始裂缝宽度对试件黏结强度的影响削弱。与无初始裂缝试件的黏结强度相比，初始裂缝宽度为0．19mm时，钢筋直径为10、14、18mm试件的黏结强度分别降低34．1％、26．7％、20．7％。

英文摘要：

Reinforced concrete structures in cold coastal regions are exposed to coupling effects of freeze-thaw cycles and chloride corrosion.Meanwhile,concrete structures cracks normally under service loads.Bond strength between reinforcement bars and concrete with initial cracks would deteriorate under coupled actions of freeze-thaw cycles and chloride corrosion.The cold marine environment was simu- lated in laboratory.To investigate the effects of crack width and bar diameter on the bond strength between steel bars and concrete,36 pull-out specimens were tested after 300 cycles of freeze-thaw alternatively 100 times of seawater immersion.The results showed that the bond strength between steel bar and concrete decreased as the width of the initial crack or the diameter of the steel bar increased.With increasing the diameter of the steel bars, the effect of the initial cracks on the bond strength was weakened.Compared with specimens without initial cracks,when the width of initial crack was 0.19mm,the bond strength of the specimens with bar diameter of 10mm, 14mm and 18mm decreased by 34.1%, 26.7% and 20.7%,respectively.