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Abstract

The near-surface mounted (NSM) strengthening technique, in which pultruded fiber reinforced polymer (FRP) plates or bars are adhesively bonded into grooves cut in the concrete cover, has proven to overcome several of the drawbacks of externally bonded FRP plates on reinforced concrete flexural members. However, as research on the NSM technique is relatively recent, the theoretical foundation for its application is not yet as complete, and some of the debonding mechanisms are not yet fully understood. This paper presents the main findings of a literature review aimed at identifying the existing analytical models to predict the debonding strength of reinforced concrete flexural elements retrofitted with NSM FRP strips, and of a thorough assessment of the adequacy of such models by comparison with all relevant published experimental data. It is concluded that for debonding of NSM FRP strips induced by flexural (or flexural-shear) cracking or the critical diagonal shear crack of the reinforced concrete member, the currently available models capture the behavior of the debonding mechanism and provide reasonably conservative estimations of the debonding strength. However, for debonding induced by stress concentrations at the strip ends, existing models do not fully capture the debonding behavior and as such, are shown to be excessively conservative.

Keywords

near-surface mounted FRP strengthening debonding mechanisms analytical models

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References

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Assessment of the Predictive Performance of Existing Analytical Models for Debonding of Near-Surface Mounted FRP Strips

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