Finite element analysis of locally corroded reinforced concrete beams for FRP strengthening

Pao Yue-kong Library Electronic Theses Database

Finite element analysis of locally corroded reinforced concrete beams for FRP strengthening

 

Author: Huang, Ning
Title: Finite element analysis of locally corroded reinforced concrete beams for FRP strengthening
Degree: M.Sc.
Year: 2009
Subject: Hong Kong Polytechnic University -- Dissertations.
Reinforced concrete.
Fiber-reinforced concrete.
Fiber reinforced plastics.
Finite element method.
Department: Dept. of Civil and Structural Engineering
Pages: vii, 87 leaves : col. ill. ; 30 cm.
Language: English
InnoPac Record: http://library.polyu.edu.hk/record=b2329747
URI: http://theses.lib.polyu.edu.hk/handle/200/3974
Abstract: Corrosion of steel reinforcement due to the penetration of chloride ions is an important concern for the durability of reinforced concrete (RC) structures exposed to marine environments. It not only leads to the loss of the steel reinforcement section, but also leads to cracks at the concrete surface, the reduction of bond strength between the steel reinforcement and the concrete and spalling of the concrete cover. Extensive research has been conducted to investigate the structural performance of corroded RC beams, but it is noticed that most of them was based on an assumption that the corrosion of the steel reinforcement is uniformly distributed in a structural component. However, in reality, the corrosion of steel reinforcement is more frequently observed at a specific location, e.g. a location where the access of seawater is concentrated or a location with large bending moment, which usually corresponds to a large crack width in concrete. Up to now little has been understood about how such localized corrosion of steel reinforcement influences the serviceability as well as the safety of an RC structural component probably due to the difficulty in realizing such localized corrosion in steel reinforcement through an electrochemical deterioration method in a laboratory test. Moreover, although limited research has indicated that fiber-reinforced polymer (FRP) plates/sheets can be used to strengthen corroded RC beams, no design approaches have been established for strengthening of RC beams with localized corrosion using FRP plate/sheets. This study, therefore, aims to develop a reliable finite element (FE) model following the approach of Chen et al. (2008) to predict how the localized corrosion of the internal steel reinforcement affects the structural performance of a locally corroded RC beam, as well as study further how a locally corroded RC beam strengthened with externally bonded FRP sheets/plates behaves mainly in terms of the load-carrying capacity and cracking behavior. The numerical results predicted by the FE model not only indicate clearly a significant reduction of the load-carrying capacity in all locally corroded RC beams compared to the non-corroded one. The mean flexural crack spacing increases with the steel corrosion level in all locally corroded RC beams. Given the same corrosion level, the locally corroded and uniformly corroded RC beams exhibited significantly different crack patterns although they had similar load-carrying capacity. It is found that the plane sectional assumption is no longer applicable for predicting the load-carrying capacity of corroded RC beams and the bond-slip behavior of corroded steel reinforcement to concrete interface must been correctly considered in the FE model. The FE analysis also shows that the ultimate load-carrying capacity and serviceability of locally corroded RC beams under flexure can be significantly increased after being strengthened with externally bonded fiber-reinforced polymer (FRP) plates.

Files in this item

Files Size Format
b23297475.pdf 17.08Mb PDF
Copyright Undertaking
As a bona fide Library user, I declare that:
  1. I will abide by the rules and legal ordinances governing copyright regarding the use of the Database.
  2. I will use the Database for the purpose of my research or private study only and not for circulation or further reproduction or any other purpose.
  3. I agree to indemnify and hold the University harmless from and against any loss, damage, cost, liability or expenses arising from copyright infringement or unauthorized usage.
By downloading any item(s) listed above, you acknowledge that you have read and understood the copyright undertaking as stated above, and agree to be bound by all of its terms.

     

Quick Search

Browse

More Information