钢筋混凝土桥梁锈胀开裂时间模型敏感性

发布时间：2018-02-16 18:18

本文关键词： 桥梁工程氯离子侵蚀敏感性分析开裂时间模型　出处：《长安大学学报(自然科学版)》2014年06期 　论文类型：期刊论文

【摘要】：为了对氯离子侵蚀下在役钢筋混凝土桥梁进行全寿命预测,需要选择更为合理的混凝土锈胀开裂时间模型。分别应用单因素变化、多因素变化和敏感性指标对在氯离子侵蚀环境下的10个开裂时间模型进行敏感性分析,得到开裂时间tcr对各输入参数的敏感性大小,并确定出合适的模型。研究结果表明:3种敏感性分析方法的结果基本一致;单因素敏感性分析得出开裂时间tcr对钢筋锈蚀率icorr(jcorr)、锈蚀物密度ρr、氯离子渗透区域δ0、钢筋摩尔质量与锈蚀物的质量之比αm的敏感性较高,这4个参数属于模型中的重要参数;多因素敏感性分析得出tcr对icorr的敏感性增强,同时发现混凝土保护层厚度c、钢筋直径d和混凝土抗拉强度ft变化所引起的tcr变化率的改变也较为显著;敏感性指标分析得出参数c、d和ft的敏感性较单(多)参数分析略有提高;包含以上7个参数,确定文献[4]提出的模型8为适于工程应用的合理模型。
[Abstract]:In order to predict the whole life of existing reinforced concrete bridges under chloride ion erosion, a more reasonable model of corrosion cracking time of concrete should be selected. The sensitivity of 10 cracking time models under chloride erosion environment was analyzed by multi-factor variation and sensitivity index. The sensitivity of cracking time tcr to each input parameter was obtained. The research results show that the results of the three sensitivity analysis methods are basically consistent; Single factor sensitivity analysis shows that cracking time tcr is sensitive to corrosion rate of steel bar, corrosion density 蟻 r, chloride ion permeation region 未 0, molar weight of reinforcement to corrosion mass 伪 m, and these four parameters are important parameters in the model. The sensitivity of tcr to icorr is enhanced by multi-factor sensitivity analysis. It is also found that the change rate of tcr caused by the thickness of concrete cover, the diameter of steel bar d and the change of tensile strength ft of concrete is significant. Sensitivity index analysis shows that the sensitivity of parameters cnd and ft is slightly higher than that of single (multiple) parameter analysis, and that the model 8 proposed in reference [4] is a reasonable model suitable for engineering application.
【作者单位】：西安建筑科技大学理学院;西安建筑科技大学土木工程学院;
【基金】：国家自然科学基金项目(51278403,50725824) 陕西省“13115”科技创新工程项目(2010ZDKG-55) 陕西省教育厅科学研究计划项目(14JK1419)
【分类号】：U445.7

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