Effects of Pre-Damage on Stress-Strain Relationship of Partially Confined Concrete

Existing studies have demonstrated that fiber-reinforced polymer (FRP) confinement is an effective way of enhancing the strength and ductility of damaged columns. An experimental and analytical exploration is undertaken to study the mechanical behavior of damaged columns and then subsequently repaired with FRP strips. The effectiveness of the repair technique on the strength and transition stress, initial, and hardening modulus is examined by using an existing model for the stress-strain parameters of FRP-confined pre-damaged concrete. These models enable the effectiveness to be scrutinized in terms of confinement pressure and damage degree. The current study has highlighted that the lateral confinement pressure affects the dilation phenomenon of FRP-confined pre-damaged concrete. The study also divulged that the classical model of confined concrete by the previous studies is not only applicable to the original form of the structures but also applicable to its damaged state. Furthermore, the current work extends the application of the energy balance method to the FRP-confined pre-damaged concrete.