冰雪灾害性天气后南京长江第二大桥结构混凝土损伤评估研究

Study on Evaluation of the Damage of Structure Concrete at Second Yangtze River Bridge in Nanjing after the Snow and Ice Disaster Weather

冰雪灾害天气下冻融损伤和使用融雪剂会对桥梁结构混凝土性能有一定影响。本文对冰雪灾害天气后南京长江第二大桥不同结构部位混凝土外观、力学性能、碳化深度、钢筋保护层厚度、混凝土氯离子含量进行检测,与冰雪灾害天气前结构混凝土各项性能进行对比,对南京长江二桥结构混凝土损伤状况进行评估。检测结果表明,冰雪灾害性天气使结构混凝土可见裂缝数量增加,裂缝宽度有进一步扩展趋势,结构混凝土强度、碳化深度、混凝土保护层厚度变化不大,冰雪灾害天气后混凝土中氯离子含量比冰雪灾害天气前混凝土氯离子含量有所增加。冰雪灾害天气对南京长江二桥各个结构部位混凝土损伤较小。

Freezing and thawing damage, deicing chemicals have larger effect on the properties of structure concrete.In this paper, after ice and snow disaster weather, the appearance, mechanical properties, carbonation depth, the protective layer and the chloride ion content of the concrete at difference structural region of Second Yangtze River Bridge in Nanjing were tested, compared to those at the begain of ice and snow disaster weather, the damage state of structure concrete was thoroughly evaluated. The test results showed that the ice and snow disaster weather result in the more amout concrete crack and the wider concrete crack, the mechanical properties, the carbonation depth, the protective layer of the concrete have not significant change, the chloride ion content of the concrete after ice and snow disaster weather increase. The ice and snow disaster weather has a smaller damage on the properties of the concrete at difference structural region.