Interfacial bond behavior between FRP and concrete substrate

FRP application is a very effective way to repair and strengthen structures that have become structurally inefficient over their life span. This study concerns with the understanding of the debonding failure mechanism in FRP strengthened RC beam. It is important to predict the limit at which FRP shall debond from the beam in order to arrest premature failures. Currently existing models lack the thoroughness of bond predictability. This is mainly due to development of any particular model on the basis of a smaller amount of tested data usually from the researcher itself. Hence, there is a need to compare the existing work when applied to an extensive database. To verify this concept experimental work was collected from literature consisting of 351 concrete prisms bonded to FRP and tested in direct shear tests. Further a database of 163 beams tested in three point and four point bending tests was collected from literature. Various models are applied to these databases and their behavior analyzed. Finally a new model is developed to ascertain the premature failure of the strengthened RC beam.