梁內受腐蝕預應力鋼絞線應力狀態(tài)研究*
韓基剛，宋玉普，宋世德，張麗華
- 摘 要
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(大連理工大學海岸和近海工程國家重點實驗室， 大連 116024)［摘要］通過6根受腐蝕鋼絞線部分預應力混凝土梁的彎曲疲勞試驗，研究了疲勞荷載作用下梁的疲勞壽命及受腐蝕鋼絞線的應變發(fā)展規(guī)律。試驗結果表明：鋼絞線腐蝕前，梁的疲勞損傷、鋼絞線腐蝕率的增大以及最大荷載水平的提高均使梁的疲勞壽命顯著降低；利用FBG傳感器能夠準確地測出梁內鋼絞線的應變分布；梁內受腐蝕鋼絞線的最大應變增量、殘余應變均符合三階段發(fā)展規(guī)律，并建立了各自與荷載循環(huán)次數之間的關系表達式。以上結果可以為疲勞荷載作用下，腐蝕鋼絞線預應力混凝土橋梁的耐久性設計提供參考。［關鍵詞］預應力混凝土梁; 鋼絞線腐蝕; 疲勞; FBG傳感器; 鋼絞線應變中圖分類號：TU375 文獻標識碼：A 文章編號：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*國家高技術研究發(fā)展計劃項目(863計劃)(2007AA11Z133)，遼寧省教育廳科技計劃項目(2008T231)。作者簡介：韓基剛，博士研究生，Email:hanjigang_1982@163.com。參考文獻［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］朱爾玉,劉椿,何立,等.預應力混凝土橋梁腐蝕后的受力性能分析［J］.中國安全科學學報,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］孫新喜. 預應力混凝土結構的腐蝕與防護［J］.建筑結構,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.腐蝕鋼絞線預應力混凝土梁的受彎性能試驗研究［J］.建筑結構學報,2010,31(2):78-84.［8］刁進東.腐蝕預應力混凝土結構力學性能的試驗研究［D］.大連:大連理工大學,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.
