| Specially shaped concrete column structure is a new structure with special shaped column of T-shaped, L-shaped, cross-shaped and Z-shaped section. Usually, the width of specially shaped column section is same with the thickness of filler wall. With special-shaped column to replace traditional rectangular cross section column, can effectively avoid the bulge of column indoors, it can not only improve utilization rate of building space and increase available clearance of building, but also decrease structure weight. However, the joints of special shaped concrete column structure are weaker compared with traditional rectangular frame structure. The special shaped concrete column structure are not suitable for high-rise building in strong earthquake zones because of the brittle shear failure in the core area of the beam-column joints. Researchers show that with shape steels installed in the core area of the beam-column joints can improve the seismic capacity of special shaped Concrete column structure. But the steel plates need to be drilled to place rebar of joints during the installment of shaped steel, which will increase great difficulties to practical construction. To solve the problem, professor Pan Wen and Lu Xingxin have developed a new joint with steel plate connected by vierendeel truss in 2012, and FEM analysis using ABAQUS software was carried out for it.This article improves the new style of steel point, mentioned above by inserting the short bars in some holes in the steel plates, which will enhance the bond between steel and concrete and the major work of the paper can be classified as below:1. Eight full size joints of R. C. frame with special-shaped columns are constructed, which included three common special-shaped column joints, three new joints, and two improved joints.2. Based on three joints of L-shaped section, which include common, new and improved joints respectively, pseudo-static tests were performed for the three kind of joints.By the obsevertion of actual construction process, the feasibility of construction processes were analyzed and then the solving measures for the problems during construction were puts forward.Baed on the results of the pseudo-static tests of 3 L-shaped special-shaped concrete column frame structures joints under low-cyclic loading, the cracks development, failure processes of the special-shaped column frame joints, and the shear bearing capacity, hysteresis behavior, energy dissipation capacity and stiffness degradation of the core zone of joints were analyzed. Tests results show that the shear bearing capacity of the core zone of joints can be improved by the inserting of shaped steel, which can be a reference for subsequent researchs on the connections of steel shaped column. |
