Finite element modeling of exterior beam-column joints strengthened by ferrocement under cyclic loading

This paper aims to study the seismic performance of exterior beam-column joints in building frames strengthened by ferrocement using nonlinear finite element analysis. Firstly, the proposed model was used to predict experimental results successfully. Secondly, a parametric study was carried out to assess the behavior of such joints with different additional variables. The studied variables were the level of axial loading on the column, compressive strength of specimens, percentage of longitudinal reinforcement in the beam, and orientation of expanded wire mesh in ferrocement layer, for specimens strengthened by different number of ferrocement layers. It was found that strengthening specimens by ferrocement reduced the effect of axial loading level and longitudinal steel ratio in the beam on the ultimate load of studied specimens. In addition, changing the orientation angle of expanded wire mesh from 60° per ferrocement layer to 45° has a minor effect on the ultimate load but it has a significant effect on the ductility of studied specimens. The effect of orientation angle became less significant on the ductility with increasing the number of ferrocement layers used for strengthening. These findings would be helpful to the engineers to develop suitable, feasible and efficient upgrading technique for poorly designed building frame structural joints in seismic zones.