Comparative Assessment of Analytical Strength Models for Predicting the Compressive Strength of FRP-Confined Concrete Cylinders

Aksakal A. K.

International Journal of Engineering and Applied Sciences, cilt.18, sa.2, ss.1-18, 2026 (Hakemli Dergi)

Özet

Fiber-reinforced polymers (FRP) are widely used for strengthening and repairing reinforced concrete members due to their high mechanical properties and ease of application. In this study, the performance of 12 analytical strength models selected from the literature was investigated for predicting the compressive strength of FRP-confined concrete cylinders. The models were assessed using published experimental results for C20, C40, and C50 cylinders confined with CFRP and GFRP. Predictive performance was evaluated using APE, MAPE, RMSE, SD(APE), and Willmott’s index of agreement (d). The models generally agreed with the experimental data, with an MAPE of 14.7%. The Youssef et al. and Wu and Wei models demonstrated the best performance. The Youssef et al. model achieved the lowest MAPE and SD(APE) values of 9.1% and 3.91%, respectively, whereas the Wu and Wei model produced a comparable MAPE of 9.2%, the lowest RMSE of 7.128, and the highest d value of 0.983. The Toutanji model showed the weakest predictive performance. It was determined that model performance varied with FRP type, concrete strength, and confinement level, and that error rates increased, particularly at high confinement levels and in GFRP-confined specimens. As a result, selecting an appropriate strength model is critical for achieving reliable results.