Core Reinforcement On The Seismic Performance Test Study

Under the effect of earthquake, situation of force on the reinforced concrete columns is very complex. That will cause failure of reinforced concrete columns and lead to the collapse of buildings if the concrete columns are not ductile and strong enough, which can be prevented by improving the ductility of concrete columns. In engineering practice, using Concrete Filled Steel Tubular Columns and Steel Encased Concrete Columns are effective methods. The subject of this thesis focused on the CRC with steel as center framework.Based on the high axial compression ratio under horizontal cyclic loading test on 6 CRCs, processes and modes of speciments' destroy were described. Through investigation on the character of the compression and destroy of the speciments, the major factors affecting the ductility of CRC are discussed. In the result, the earthquack resistance were analized on many aspects. The research indicated that axial load ratio, ratio of tie per volumn and ratio of center rebar affected more on the ductility, elasticity and plasticity of the CRC, and increase the ratio of center rebar and tie can efficiently improve the ductility of the CRC under high axial load ratio. Morever, CRC with steel as center framework is well earthquake resistant, since center framework can strenghen the concrete columns. Finally, an advised maximum of axial load ratio on the CRC is given.