梁内受腐蚀预应力钢绞线应力状态研究*
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(大连理工大学海岸和近海工程国家重点实验室， 大连 116024)［摘要］通过6根受腐蚀钢绞线部分预应力混凝土梁的弯曲疲劳试验，研究了疲劳荷载作用下梁的疲劳寿命及受腐蚀钢绞线的应变发展规律。试验结果表明：钢绞线腐蚀前，梁的疲劳损伤、钢绞线腐蚀率的增大以及最大荷载水平的提高均使梁的疲劳寿命显著降低；利用FBG传感器能够准确地测出梁内钢绞线的应变分布；梁内受腐蚀钢绞线的最大应变增量、残余应变均符合三阶段发展规律，并建立了各自与荷载循环次数之间的关系表达式。以上结果可以为疲劳荷载作用下，腐蚀钢绞线预应力混凝土桥梁的耐久性设计提供参考。［关键词］预应力混凝土梁; 钢绞线腐蚀; 疲劳; FBG传感器; 钢绞线应变中图分类号：TU375 文献标识码：A 文章编号：1002-848X(2013)21-0069-05Study on stress state of corroded prestressed steel strands in beamsHan Jigang, Song Yupu, Song Shide, Zhang Lihua(State Key Laboratory of Coastal and Offshore Engineering, Dalian University of Technology, Dalian 116024, China)Abstract: Tests were carried out for 6 partially prestressed concrete beams with corroded steel strands under fatigue loading. The fatigue lives of beams and the strain developing process of corroded steel strands were investigated. The results show that the fatigue lives of partially prestressed concrete beams are shortened considerably on the condition that the fatigue damage at an advanced stage of corrosion, the raising of the corrosion rate of steel strands and maximum load level. The FBG sensors are good at measuring strain distribution of steel strands in beams. The maximum strain increment and residual strain of the corroded steel strands accord with the law of the three stages development. The relational expressions between the maximum strain increment, residual strain and the number of cycle loading were established. The results may provide the reference for the durability design of prestressed concrete bridge with corroded steel strands under fatigue loading.Keywords: prestressed concrete beam; corroded of steel strand; fatigue; FBG sensor; strain of steel strand*国家高技术研究发展计划项目(863计划)(2007AA11Z133)，辽宁省教育厅科技计划项目(2008T231)。作者简介：韩基刚，博士研究生，Email:hanjigang_1982@163.com。参考文献［1］S M BRUCE, P S MC CARTEN, S A FREITAG, et al. Deterioration of prestresse concrete bridge beams［R］.New Zealand:Land Transport New Zealand Report,2008.［2］朱尔玉,刘椿,何立,等.预应力混凝土桥梁腐蚀后的受力性能分析［J］.中国安全科学学报,2006,16(2):136-140.［3］M S DARMAWAN, M G STEWART. Effect of pitting corrosion on capacity of prestressing wires［J］. Magazine of Concrete Research,2007,59(2):131-139.［4］孙新喜. 预应力混凝土结构的腐蚀与防护［J］.建筑结构,2007,37(7):68-69.［5］DAVID TREJO, RADHAKRISHN G PILLAI, MARY BETH D HUESTE, et al. Parameters influencing corrosion and tension capacity of post-tensioning strands［J］. ACI Material Journal, 2010,106(2):144-153.［6］U NUMBERGER. Corrosion induced failure mechanisms of prestressing steel［J］. Materials and Corrosion, 2002, 53(8):591-601.［7］李富民,袁迎署.腐蚀钢绞线预应力混凝土梁的受弯性能试验研究［J］.建筑结构学报,2010,31(2):78-84.［8］刁进东.腐蚀预应力混凝土结构力学性能的试验研究［D］.大连:大连理工大学,2009.［9］MAASJABT R，ALAVIE T，MEASURES M R. Fiber-optic bragg grating sensors for bridge monitoring［J］. Cement and Concrete Composite, 1997，19:21-33.
