Abstract: The applicability and prediction accuracy of three calculation models (Lam′s model, Wei′s model and Lim′s model) for ultimate stress and strain was evaluated based on test database of FRP-confined seawater sea-sand concrete (SSC) square columns. Higher prediction accuracy of models for ultimate stress compared with that of models for ultimate strain can be found through the analysis results. Among the three models for predicting ultimate stress, Lam′s model exhibits relatively higher accuracy with the smallest average absolute error AAE equal to 12.4%. AAE of Lim′s model and Wei′s model is 16.8% and 18.2%, respectively. Among the three models for predicting ultimate strain, Lim′s model has the highest accuracy (AAE=14.3%) while Lam′s model and Wei′s model largely underestimate the ultimate strain of FRP-confined SSC square columns, with the average ratio of prediction value to experimental value Mean equal to 68.1% and 56.1%, respectively. Therefore, among the three models, Lam′s model shows the highest accuracy for ultimate stress prediction, while Lim′s model is the best for ultimate strain prediction.

Key words: FRP confinement, seawater sea-sand concrete square columns, ultimate stress, ultimate strain, prediction accuracy