Keywords
Bond strength; steel bar; corrosion; bond stress-slip; repeated loading
Abstract
The corrosion of reinforcing steel bar embedded in concrete leads to the bond deterioration. This literature review summarises the influence of corrosion on bond strength and bond-slip behaviour. The influence of corrosion on bond strength has been intensively investigated and the main influencing parameters, including the corrosion conditions of steel bars, the geometry and the corrosive environment, have been well recognized. Based on the previous investigations and the author’s experimental work, an improved bond strength model, which can account for various parameters and is proved to agree well with experimental results in the literature, is developed. The literature survey also indicates that the surface crack width is appropriate to be the governing parameter for the evaluation of bond strength. For the bond-slip behaviour of corroded RC, the published experimental results indicate that the bond-slip mechanism is similar to that of non-corroded RC, however, the researchers have different views regarding the influence of corrosion on some of the parameters that shape the bond-slip curves. A comprehensive bond-slip model for corroded RC has been developed by the authors considering various parameters, such as the confinements and the corrosion conditions of stirrups. This paper also reviews the bond behaviour of corroded RC under repeated loading. The research by the authors suggests that the repeated loading shows no significant influence on the bond strength of corroded RC, and the bond-slip behaviour is characterized by the progressive increase of residual slip, which is the same to that of non-corroded RC. To better understand the bond behaviour of corroded RC, the further studies are needed with respect to the influence of environment on the bond deterioration, the correlations between the bond behaviour and the surface crack width, and the bond-slip behaviour of corroded RC under repeated loading with various loading scenarios.
The bond behaviour between concrete and corroded reinforcement: state of the art
The corrosion of reinforcing steel bar embedded in concrete leads to the bond deterioration. This literature review summarises the influence of corrosion on bond strength and bond-slip behaviour. The influence of corrosion on bond strength has been intensively investigated and the main influencing parameters, including the corrosion conditions of steel bars, the geometry and the corrosive environment, have been well recognized. Based on the previous investigations and the author’s experimental work, an improved bond strength model, which can account for various parameters and is proved to agree well with experimental results in the literature, is developed. The literature survey also indicates that the surface crack width is appropriate to be the governing parameter for the evaluation of bond strength. For the bond-slip behaviour of corroded RC, the published experimental results indicate that the bond-slip mechanism is similar to that of non-corroded RC, however, the researchers have different views regarding the influence of corrosion on some of the parameters that shape the bond-slip curves. A comprehensive bond-slip model for corroded RC has been developed by the authors considering various parameters, such as the confinements and the corrosion conditions of stirrups. This paper also reviews the bond behaviour of corroded RC under repeated loading. The research by the authors suggests that the repeated loading shows no significant influence on the bond strength of corroded RC, and the bond-slip behaviour is characterized by the progressive increase of residual slip, which is the same to that of non-corroded RC. To better understand the bond behaviour of corroded RC, the further studies are needed with respect to the influence of environment on the bond deterioration, the correlations between the bond behaviour and the surface crack width, and the bond-slip behaviour of corroded RC under repeated loading with various loading scenarios.
