Experimental Study On Seismic Performance Of Steel Reinforced Super-high-strength Concrete Column Joints

With the development of the modern buildings and the increasing in height and span of the buildings, reinforced concrete (RC) structure has been incompetent for the change. Despite the characteristic of increasing bearing capacity of member, reducing of sectional dimension of super-high-strength concrete (SHSC) structure, it is not in disregard of disadvantage of SHSC that has the character of bad ductility and great friability. Steel reinforced super-high-strength concrete structure, which is the new type of structure, is formed by steel encased in SHSC structure. That steel and SHSC can interact each other is contributed to the improvement of strength of steel and SHSC respective in steel SHSC structure and the amelioration of the character of bad ductility and great friability of SHSC. Therefore, steel SHSC structure has great development potential and development space. Although a lot of researches on the seismic behavior of steel reinforced concrete (SRC) both at home and abroad have been made, studies on steel SHSC structure are not enough. Based on this, the study on seismic behavior of the steel SHSC column/RC beam joints is presented.By the tests of steel SHSC column/RC beam joints under the cyclic reversed loading, the process of load bearing and failure mechanism are studied. A detailed description of the test process and a preliminary analysis are given. The seismic behavior of the steel SHSC column/RC beam joints is analyzed. At the same time, the ductility, the energy dissipation capacity, strength deterioration and stiffness deterioration are studied. The strains of steel, stirrup and reinforcement of the beams in the joint core are analyzed.The theoretic analysis of the steel SHSC column/RC beam joint is presented, and the shear calculating method of the steel SHSC column/RC beam joint core is discussed. According to the experimental data, the mechanism of crack resistance of the joint is studied. After that, a calculating formula of crack resistance of the joint is derived. The results indicate that the calculations agree well with those obtained on test.