Confinement models of GFRP-confined concrete: Statistical analysis and unified stress-strain models

This paper presented a comprehensive assessment of 22 existing stress models and 13 strain models, which were developed for glass fiber reinforced polymer (GFRP)-confined concrete in uniaxial compression. In addition, a reliability evaluation of these stress and strain models was performed. A database including 212 GFRP-confined cylindrical concrete specimens was collected and analyzed to evaluate the performance of these stress and strain models. The accuracy and applicability assessment of these models were carried out by 2 test and the Pearson correlation coefficient r, and the Monte Carlo-JC method was used by for the reliability assessment. Based on the evaluation, it was found that the unconfined concrete strength fco is the most important parameter which determines the accuracy of these stress and strain models for GFRP-confined concrete. Most stress and strain models used in this study can predict the ultimate axial strength and strain of the GFRP-confined concrete appropriately, although some scattered points exist for some models. In addition, it was found that all these models satisfy the command of reliability even some models are too conservative. Based on the database, unified stress and strain models were proposed showing better applicability.