Bond strength and development length of glass fiber-reinforced polymer bar in unconfined self-consolidating concrete

Although there are different models for determining bond strength and development length of glass fiber-reinforced polymer bar in normal concrete, they cannot evaluate the interfacial behavior of glass fiber-reinforced polymer bar in self-consolidating concrete accurately. This study presents more precise and efficient models for bond strength and development length of glass fiber-reinforced polymer bar in self-consolidating concrete than existing equations. The performance of a model depends very much on test data. Previous researches do not have enough data of bond strength and development length of glass fiber-reinforced polymer bar in self-consolidating concrete. So, more extensive data are needed to investigate the efficiency and accuracy of a model. To solve this problem, direct pull-out tests are performed in this study. Unlike existing models for bond strength and development length, proposed models perform very well for predicting bond strength and development length of glass fiber-reinforced polymer bar in self-consolidating concrete. The new models considerably decrease the deviation of existing models.