Fracture model for predicting concrete cover-cracking induced by steel corrosion based on interface bond state  

作　　者：王显利 郑建军 吴智敏 

机构地区：[1]State Key Laboratory of Coastal and Offshore Engineering,Dalian University of Technology [2]College of Traffic Construction Engineering,Beihua University [3]College of Civil Engineering and Architecture,Zhejiang University of Technology

出　　处：《Journal of Shanghai University(English Edition)》2009年第3期219-224,共6页上海大学学报（英文版）

基　　金：supported by the National Natural Science Foundation of China (Grant No.50178003)

摘　　要：Time-to-cracking of the concrete cover induced by the steel corrosion is one of the critical problems faced by engineers, operators and asset managers in making strategies for the maintenance and repairs of reinforced concrete （RC） structures affected by corrosion. In this paper, a theoretical model for predicting the time-to-cracking is derived by assuming the bond between the steel bar and the concrete as a linear combination of perfectly smooth and bonded. The model takes into account the characteristics of existing exiguous flaws and initial cracks in the concrete before the load acting on RC structures. The validity of the proposed model is prehminarily verified by comparing the obtained results with the available experimental results. A remarkable advantage of the proposed method is its apphcation to the prediction of the service life of RC structures, made of the deformed steel bars as well as the round bars. By determining an experimental constant a, which is related to the interface bond state between the steel bar and the concrete, the service life of RC structures can be predicted using the proposed scheme. Analysis of major factors affecting the time-to-cracking demonstrates that the length of the initial crack affects the service life of RC structures significantly. Moreover, the larger cover thickness and the smaller diameter of the steel bar within a certain range are beneficial to prolonging the time-to-cracking.Time-to-cracking of the concrete cover induced by the steel corrosion is one of the critical problems faced by engineers, operators and asset managers in making strategies for the maintenance and repairs of reinforced concrete （RC） structures affected by corrosion. In this paper, a theoretical model for predicting the time-to-cracking is derived by assuming the bond between the steel bar and the concrete as a linear combination of perfectly smooth and bonded. The model takes into account the characteristics of existing exiguous flaws and initial cracks in the concrete before the load acting on RC structures. The validity of the proposed model is prehminarily verified by comparing the obtained results with the available experimental results. A remarkable advantage of the proposed method is its apphcation to the prediction of the service life of RC structures, made of the deformed steel bars as well as the round bars. By determining an experimental constant a, which is related to the interface bond state between the steel bar and the concrete, the service life of RC structures can be predicted using the proposed scheme. Analysis of major factors affecting the time-to-cracking demonstrates that the length of the initial crack affects the service life of RC structures significantly. Moreover, the larger cover thickness and the smaller diameter of the steel bar within a certain range are beneficial to prolonging the time-to-cracking.

关 键 词：reinforced concrete （RC） time-to-cracking service life CORROSION corrosion-induced expansive force 

分 类 号：TU375[建筑科学—结构工程] TQ323.41[化学工程—合成树脂塑料工业]