EXPERIMENTAL STUDY ON ASEISMIC BEHAVIOR OF RC BEAM-COLUMN JOINTS STRENGTHENED WITH PRESTRESSED STEEL STRIPS

A new method for retrofitting the RC beam-to-column joints with prestressed steel strips was proposed, based on the analysis and navigation of existing retrofitting methods. The experimental study on 4 specimens retrofitted with prestressed steel strips and 1 specimen without retrofit were performed to investigate their aseismic performance. All of the specimens were tested under cyclic-reserve loading to verify and validate the effect of the retrofitted method with prestressed steel strips. The influence of steel strips space in the retrofitted joint core region and in the adjacent region, and of reinforcement layout on the aseismic performance of strengthened joints were studied. The final failure mode, hysteretic behavior, energy dissipation capacity, and ductility of specimens were analyzed by the experiment study. It is found that the specimens strengthened with prestressed steel strips behaved higher shear resistance because the prestressed steel strips effectively restrain the development of cracks in the joint core area and reduce the shear deformation of the joint core area. As a result, the failure mode of specimens changed from the combination of flexural failure of beams and shear failure of joints to the flexural failure of beams. The aseismic performance index of specimens such as bearing capacity,energy dissipation capacity, ductility and stiffness degradation have improved greatly.