Comparison of Novel Bond Models for ETS FRP Bar Method with the Existing Bond Model

Embedded through-section (ETS) fibre-reinforced polymer (FRP) technique is a new rehabilitation technique which has a number of advantages over existing methods. Because of the lack of a comprehensive analytical model on the bond behavior of the ETS FRP bar method, a novel analytical model has been proposed to predict bar maximum pull-out force which is written as a function of the maximum shear stress. Since, shear resistance should be obtained through experimental investigations, two models have been proposed to predict the maximum shear stress for carbon FRP (CFRP) and glass FRP (GFRP) ETS bars. Besides, there is an equation in the literature for calculating the average bond strength of ETS FRP bars. In this research, the proposed models have been compared with the existing one in prediction of maximum shear stress. Results showed that the coefficient of determination (R ) for CFRP and GFRP ETS bar models are ۰.۹۶ and ۰.۹۰, respectively, while the most accurate model that exists in the literature has an R equal to ۰.۹۱. The ratios of experimental shear stress to the predicted shear stress for three bond models are ۱.۰۰, ۱.۰۱ and ۱.۰۵, respectively, which show that the proposed models are superior to the existing one.

Keywords:

Bond Model , Embedded Through-Section , FRP Bars , Shear Strengthening