Evaluation of Bond Strength Between FRP Bars and Concrete Under Seawater Immersion Using Explainable Machine Learning Models
摘要
Floating structures are required to mitigate the issues of overcoming the land shortage in Hong Kong and other densely populated coastal cities. For this purpose, conventional steel pontoons need to be replaced by fiber-reinforced polymer (FRP) from the standpoint of durability and economy. Among various issues of FRP and concrete in coastal areas, the bond performance between FRP bars and concrete is critical in structural design and application. This study compiled 219 real pull-out test records with seven input parameters to investigate the bond performance between FRP bars and concrete under seawater immersion. Based on the dataset, three machine learning algorithms, namely Decision Tree, Random Forest, and XGBoost, were employed to construct predictive models for the bond strength between FRP bars and concrete under seawater immersion. Evaluation metrics, including R2, MAE, and RMSE, were exploited to calculate the performance of the developed models. Due to the superior predictive performance of the Random Forest model, this study further employed SHAP analysis to investigate the effects of influencing parameters on the bond strength. The developed models and the SHAP analysis provided a reference for assessing and designing bond performance between FRP bars and concrete under seawater immersion conditions.