Comparative study on proposed models and design guideline for flexural strengthening of NSM FRP in RC beams

Abstract EN

The retrofitting technique of near-surface mounting (NSM) fiber-reinforced polymer (FRP) is an alternative solution to externally bonded technique in strengthening of reinforced concrete (RC) elements, in particular a significant effect is due to improving high bond action between concrete and FRP bar.

A comparative study on four theoretical models and two design guidelines for contribution of NSM FRP bars to RC beams is reported and evaluated in this study.

A significant number of experimental results (71 tests) of RC beam specimens, reported in the literature have been collected to validate the accuracy of the theoretical models formula.

The flexural strength equations of common guideline, Canadian standard and American guideline were also used to compare the strengthening capacity of RC beams based on the available experimental results.

Apparently, theoretical models have provided accurate results compared to design guidelines, the equations showed a good match with test results by considering bond action.

One of the proposed formulas is quite satisfactory concerning both test results and the prediction of different design guidelines.