Evaluation of hybrid joints strengthened by carbon plates connecting new steel frames with existing concrete slabs

This paper introduces hybrid joints strengthened by carbon plates for connecting new steel frames onto concrete slabs, enabling rapid and effortless assembly of frames relative to traditional wall frame construction; this study proved that the use of carbon strips was efficient in strengthening the joint. The nonlinear structural response of the proposed joints with carbon strips, which can transfer moments through the interconnected components, was evaluated experimentally and numerically based on identified parameters that influence the structural behavior of retrofitted frames. The parameters are also capable of evaluating failure modes of the extended structure with vertical additions by identifying the structural behavior of the joints with carbon strips. This study performed numerical analysis based on delamination growth predictions using cohesive finite elements, in an attempt to engender better practice for cost effective analytical investigations, and demonstrated a good correlation with test data obtained from extensive experimental investigations.