Experimental Study Of Beam-Column Joints Strengthened With CFS

As a new structural engineering material, continuous carbon fiber sheet (CFS) has many advantages of excellent mechanical properties, such as high intension, convenience in use, low weight, non-dimensional increase, and immunity to corrosion, etc. In recent years, it has been put into use in the strengthening of reinforced concrete. The CFS-strengthening technique has attracted many researchers and engineers today in the world. But most of researches focus on the strengthening of beams, columns and boards. As an important part of architecture, beam-column joints strengthened with CFS have not been researched systematically. On the other hand, they have been put into use in practical engineering in large scale.In this paper, beam-column joints strengthened with CFS have been study systematically. Based on the experiments of five full-scale beam-column joints (two non-seismic joints, one seismic joints and two non-seismic joints strengthened with CFS) subjected to lateral cyclic load, the failure mode, ultimate capacity, hysteretic behavior, ductility factor etc. are compared and analyzed. The experiment results shows that CFS could significantly increase the joints' seismic capacity. Compared with non-strengthened ones, joints strengthened with CFS have a few increases on the ultimate capacity and a great deal of increase on the ductility factor. In a word, it is show that joints could be strengthened by CFS and it could be put into use in civil engineering in large scale. At the same time, experiments also show than CFS used in joints strengthening have not been make full use .The failure mode of CFS is the debond failure between concrete and steel. Conclusion are made that CFS could be used to strengthen joints in practical engineering.The finite elements method models are developed to simulate the behavior of joints strengthened with CFS. It shows the distribution of cracks and the stress distribution of the model. The hysteretic behavior of the model are made and compared with experimental results. It is show that experimental results are got well according with the theoretical results.In conclusion, some constructing and designing suggestion is put out for the strengthening of beam-column joints according to the output of the experiments.