Behaviour of repaired RC beam-column joints using welded wire mesh and jacketed with polymer modified mortar

Abstract

The performances of repaired RC exterior beam-column joints were reported in this paper. The aim of the study was to restore back the lost capacity of the beam-column joint to the original state or more. Five type of exterior beam-column joint with different position of cold joint in the column were casted and subjected to reversed cyclic loading. The damage zones were confined with welded wire mesh (WWM) of 20 mm grid size and jacketed with polymer modified mortar (PMM). Damaged specimens after repairing were also subjected to similar cyclic displacement as those of control specimens. Seismic parameters such as load carrying capacity, energy dissipation, ductility, stiffness degradation, equivalent viscous damping, damage indices and nominal principal tensile stresses were analyzed. Results show that repaired specimens exhibited better seismic performance and hence the adopted repairing strategies could be considered as appropriate. These findings would be helpful to the field engineers to adopt a suitable rapid and cost-efficient repairing technique for restoring the damaged frame structural joints for post-earthquake usage. Further, the study revealed that there is an improvement in seismic capacity of the specimens as the location of cold joint is placed away from the soffit of the beam for lower story column.