Of Cfrp Reinforcement Earthquake Serious Damage To The Concrete Frame Of The Seismic Test

CFRP has been used in the strengthened field widely because of its merits, such as light weight, high tensile strength, corrosion resistance, convenient construction and little effection for building etc. But the study of the overall RC frame strengthened by CFRP sheets is just started. Especially, the study of the RC frame strengthened by CFRP sheets after serious damaged because of the earthquake is less. As there are many reconstruction works after earthquake, the study of the strengthened serious damaged RC structure has important significance and value of engineering applications. The seismic performances of the RC frame strengthened by CFRP sheets after destroyed will be studied.Based on two layers of a industry building as project background, a R.C frame test model (KJ-1) was designed with the scale 1:3. First of all, the experiment under low-cycle repeated load is carried to the R.C frame to achieve the greatest bearing capacity. And then, the destroyed RC frame is strengthened by CFRP sheets (KJ-1 A) on the joints, the end of the beam and the column. At last, the same experiment is done to the KJ-1 A again until to destroy.Based on the experiments, the force performance, the development of cracks, failure modes, the load-displacement hysteresis curves, the load-skeleton curves, displacement ductility and hysteresis curves of the longitudinal steel bar are comparaed. The CFRP hysteresis curve of the beam and column of the damaged RC frame strengthened by CFRP sheets are analyzed. The seismic performances of the damaged RC frame strengthened by CFRP sheets are also studied. The results show that the cracking load, yielding load and destructive load of strengthen frame are improved. There are more full hysteresis loop and energy dissipation capacity and ductility for strengthen frame. The stiffness degradation of the strengthen frame is improved effectively. The longitudinal steel bar's strain of the beam and column can be deduceed because of CFRP. The CFRP hoops on the beam and column play a good role in constraining concrete and delay the emergence and development of the cracks. The frame's load-bearing capacity is improved.In addition, the static elastoplasticity analysis of the RC frame is performed by the use of the SAP2000 program. The analysis results show that the destruction mechanism of the RC frame is same as the results obtained in the experiment.