Re-evaluation of existing tests on RC connections using post-installed reinforcing bars

Abstract

Post installed rebars offer a convenient and robust solution for rehabilitation, retrofit and strengthening of reinforced concrete structures, whenever additional structural members might be required. Although certain post installed rebars have significantly higher bond strength as compared to cast in systems, presently they are considered equivalent to corresponding cast-in systems. The present paper focuses on the comparison of behavior of RC connection using post-installed and cast-in reinforcement. The experimental investigations carried out so far have been based on a direct comparison between cast-in and post-installed reinforcing bars used to form structural connections such as column-foundation or beam-column connections. Such a comparison can be significantly affected by the assumptions made in the design and the boundary conditions used in the experiments. In this work, the existing experiments are critically reviewed and numerically re-evaluated to bring out the findings in a more rational framework. To this end, 3D finite element simulations are carried out where first the numerical model is validated against the experimental results and then the validated model is used to explore the influence of the assumptions and boundary conditions used in the tests on the original conclusions. It has been shown that the conclusions and inferences by the researchers who performed the tests were suitable for the test setup and test conditions used by them but may not be generalized to every case.