Data acquisition and experimental testing of joints for health monitoring of a RC building towards rehabilitation using FRPS

In the recent years, attempts have been made to upgrade existing RC ordinary moment resisting frames (OMRF) into ductile moment resisting frame (DMRF). FRP sheets can be used to prevent the plastic hinge formation at the face of the column in exterior RC joints to guarantee the strong-column weak-beam behaviour in existing OMRF under sever load conditions. In this paper, experimental investigation and data acquisition was carried out on scaled model of exterior joint in order to monitor structural health of a typical RC building under lateral loads. Two plain scaled-down specimens of this OMRF were tested under monotonic/cyclic loads to failure in which some inelastic deformations were observed to be penetrated into the joint area. An actuator with the capacity of 100kN was used to apply loading. The beam tip displacements were measured using linear variable displacement transducers (LVDTs), while a load cell was utilised to measure the applied load. Load and deflections were automatically recorded using a computerized data acquisition system. The yield strain of beam steel reinforcement was also measured using LVDTs to control loading scenarios as an alternative of using strain gages. Finally, three CFRP-retrofitted joints were tested to prove that carbon fibre can not only effectively relocate the plastic hinge away from the column face to a more favourable location but also guarantees a ductile behaviour.