Modeling cover cracking due to rebar corrosion in RC members

被引:6
作者
Allampallewar, Satish B. [1 ]
Srividya, A. [2 ]
机构
[1] Maharashtra Acad Engn, Basic Engn Dept, Pune 412105, Maharashtra, India
[2] Indian Inst Technol, Dept Civil Engn, Bombay 400076, Maharashtra, India
关键词
Concrete; Corrosion; Modulus of Elasticity; Expansive; Cracking;
D O I
10.12989/sem.2008.30.6.713
中图分类号
TU [建筑科学];
学科分类号
0813 ;
摘要
Serviceability and durability of the concrete members can be seriously affected by the corrosion of steel rebar. Carbonation front and or chloride ingress can destroy the passive film on rebar and may set the corrosion (oxidation process). Depending on the level of oxidation (expansive corrosion products/rust) damage to the cover concrete takes place in the form of expansion, cracking and spalling or delamination. This makes the concrete unable to develop forces through bond and also become unprotected against further degradation from corrosion; and thus marks the end of service life for corrosion-affected structures. This paper presents an analytical model that predicts the weight loss of steel rebar and the corresponding time from onset of corrosion for the known corrosion rate and thus can be used for the determination of time to cover cracking in corrosion affected RC member. This model uses fully the thick-walled cylinder approach. The gradual crack propagation in radial directions (from inside) is considered when the circumferential tensile stresses at the inner surface of intact concrete have reached the tensile strength of concrete. The analysis is done separately with and without considering the stiffness of reinforcing steel and rust combine along with the assumption of zero residual strength of cracked concrete. The model accounts for the time required for corrosion products to fill a porous zone before they start inducing expansive pressure on the concrete Surrounding the steel rebar. The capability of the model to produce the experimental trends is demonstrated by comparing the model's predictions with the results of experimental data published in the literature. The effect. of considering the corroded reinforcing steel bar stiffness is demonstrated. A sensitivity analysis has also been carried out to show the influence of the various parameters. It has been Found that material properties and their inter-relations significantly influence weight loss of rebar. Time to cover cracking from onset of corrosion for the same weight loss is influenced by corrosion rate and state of oxidation of corrosion product formed. Time to cover cracking from onset of corrosion is useful in making certain decisions pertaining to inspection, repair, rehabilitation, replacement and demolition of RC member/structure in corrosive environment.
引用
收藏
页码:713 / 732
页数:20
相关论文
共 21 条
[1]  
*ACI, 1985, 318 ACI
[2]   COVER CRACKING AS A FUNCTION OF BAR CORROSION .1. EXPERIMENTAL TEST [J].
ANDRADE, C ;
ALONSO, C ;
MOLINA, FJ .
MATERIALS AND STRUCTURES, 1993, 26 (162) :453-464
[3]  
[Anonymous], 2004, DESIGN CONCRETE STRU
[4]   Model for cover cracking due to rebar corrosion in RC structures [J].
Bhargava, Kapilesh ;
Ghosh, A. K. ;
Mori, Yasuhiro ;
Ramanujam, S. .
ENGINEERING STRUCTURES, 2006, 28 (08) :1093-1109
[5]  
CARASQUILLO RL, 1981, ACI J P, V78, P171
[6]  
*CEB FIP, 1970, INT REC DES CONTR CO
[7]  
CEB-FIP, 1990, COM EUR BET FED INT
[8]   A model for prediction of time from corrosion initiation to corrosion cracking [J].
El Maaddawy, Tamer ;
Soudki, Khaled .
CEMENT & CONCRETE COMPOSITES, 2007, 29 (03) :168-175
[9]  
*IS, 2000, 454 IS BUR IND STAND
[10]  
Légeron F, 2000, ACI MATER J, V97, P193