Intermediate Crack Debonding of Externally Bonded FRP Reinforcement-Comparison of Methods

Area of Science:

• Civil Engineering
• Materials Science
• Structural Engineering

Background:

• Fiber-reinforced polymer (FRP) debonding is a critical failure mode in structural retrofitting.
• Existing models and code provisions aim to predict intermediate crack (IC) debonding failure.

Purpose of the Study:

• To evaluate and compare the accuracy of seven selected models for predicting IC debonding failure.
• To assess model performance against experimental data from 58 flexural specimens.

Main Methods:

• Comparative analysis of seven debonding models: fib bulletin 14, Teng et al., Lu, Seracino et al., Said and Wu, Elsanadedy et al., and ACI 440.
• Validation using an experimental database of 58 externally bonded (EB) carbon FRP flexural specimens.
• Evaluation of prediction accuracy by comparing measured and predicted load capacities.

Main Results:

• The Said and Wu model and the Elsanadedy et al. model exhibited the highest accuracy in predicting load capacity.
• The fib bulletin 14 approach showed significant prediction dispersion and overestimations.
• Analysis considered limitations related to concrete crushing and FRP rupture.

Conclusions:

• The Said and Wu and Elsanadedy et al. models are recommended for design guidelines due to their superior predictive accuracy.
• The fib bulletin 14 approach requires further refinement for reliable application in predicting FRP debonding.