Experimental Study Of The Seismic Behavior Of BFRP Confined Circular RC Columns

According to the phenomenon of earthquake damage of buildings, it can be summed up that the destruction of RC columns cause RC structural failure even collapses. Therefore, the seismic performance of columns determines that whether the collapses of frame structure occur. However, Reinforced concrete columns, which had been built in structures, need to be reinforced because there are so many factors that affect their safety and using function. For example, the design code is unreasonable in the early, the using function of structure has been changed, the damage because of long-term using, poor performance and inadequate bearing capacity because of the aging and construction defects, etc.Comparing with other fiber materials, BFRP has many advantages and special properties. For example, the raw material is rich and our country possesses the independent intellectual property. At present, the price of BFRP is about1/8～1/5of CFRP’s and close to GFRP’s because of localization and mass production. Moreover, the ultimate strain ductility of BFRP is large so that it is particularly suitable for the seismic strengthening of structure.This thesis presents a test program on seismic behavior of RC columns strengthened by BFRP.(1) A total of seven reinforced concrete large scale circular columns were designed, whose diameter is305mm and height is1500mm. One column was not strengthened for comparison and the others were strengthened by BFRP.(2) Seven specimens under cyclic loading were tested to obtain the hysteretic curves, skeleton curve, ductile coefficient, energy dissipation, strength degeneration and failure patterns.(3) The number of BFRP layers, the area of wrapping, axial compression ratio and the type of stirrup that affect seismic behavior are studied.The result indicates that strengthened with BFRP not only increase columns’ultimate strength but also improve the performance such as energy consumption, ductility and so on.In the end, this thesis summarizes the novel ideas and raises some problems for future studies. At the same time, it provides practical experience for the research of seismic behavior of RC circular columns strengthened by BFRP.