考虑冻融损伤的钢筋混凝土桥梁氯离子侵蚀寿命预测研究

Research on chloride penetration life prediction of reinforced concrete bridge with consideration of the damage caused by freeze-thaw cycles

松花江公路大桥位于东北严寒地区,冬季时,为保障桥梁运行畅通,将在桥面上撒化冰盐以清除积雪,防止结冰,避免大桥混凝土结构遭受氯离子侵蚀和冻融循环的作用.冻融循环作用不仅会造成混凝土构件表面剥落,内部劣化,同时还加速了氯离子的侵入,从而导致混凝土中的钢筋过早脱钝、锈蚀,进而导致构件承载能力下降,结构安全性能降低.对松花江大桥进行了不同冻融损伤下的氯离子侵蚀规律试验研究,在此基础上,对大桥进行了不同冻融损伤下的氯离子侵蚀寿命预测,为大桥的后期使用和维护提供了科学依据.

Songhua jiang River Highway Bridge is located in the chilly area of Northeast China. In winter, to ensure the bridge to run smoothly, deicing salt is used to clear snow and prevent freezing. The Bridge will be subjected to chloride penetration and the freeze-thaw cycle,which will not only result in the surface spalling, internal deterioration, but also accelerate the intrusion of chloride ions, and the surface passive film of the steel bars in the concrete will destroy prematurely. Meanwhile the steel bars will rust prematurely, thus leading to the decline of carrying capacity of the components, or degradation of safety performance of the structure. The experimental study of chloride penetration considering freeze-thaw cycles was carried out,and on the basis of the study, the chloride penetration life prediction of the bridge with consideration of damage caused by freeze-thaw cycles was carried out, and scientific basis was provided for normal use or maintenance of the bridge.