Experimental Study On The Solution Of Reinforced Concrete Perpendicular Beam-Thin Wall Joints

The perpendicular beam–thin wall joint is one kind of the very important joints in the reinforced concrete frame-shear wall structure system and the frame-tube structure system which are commonly used in the high-rise buildings. The performance and the strengthening measures of the perpendicular beam–thin wall interior joints are mainly studied in this paper.Three 1:2 scale R.C. perpendicular beam–wall interior joints with different strengthening measures were tested under constant axial load on the top of the wall and cyclic vertical load at the end of the beam. The stress properties of this kind of beam– thin wall joints with different strengthening measures and geometries were also analyzed using ANSYS in this paper. Through aforementioned experiments and theoretical analyses, the following conclusion can be obtained.1. The experimental stress conditions of the perpendicular beam–wall joints at the early stage are consistent with the results of FEM elastic analysis.2. Spalling cracks resulted from tension failure of concrete in wall joint and adjacent area are primary when the thin wall(including the wall with visible wide beam) endured out-of-plane moment. The number and area of cracks on the backside of the wall with concealed columns are smaller than the wall with visible wide beam.3. The concealed columns in wall have little effect on out-of-plane flexure of the joint. The concealed columns can not enhance the bending resistance moment formed by the asymmetric shear stresses on the critical sections, thus can not improve the out-of-plane flexural capacity of the wall when the wall is thin. The lack of horizontal anchorage length of longitudinal bars is not improved also.4. The visible wide-beam plays a great role in the perpendicular beam–thin wall joint. The visible wide-beam in the wall can enlarge the effective critical area, therefore enhance the bending resistance moment formed by the asymmetric shear stresses on the critical sections. So out-of-plane flexural capacity of the wall can be increased significantly. The anchorage of longitudinal bars becomes better because the lack of horizontal anchorage length of longitudinal bars is improved.5. The torsional failure of the visible beam in the perpendicular beam–thin wall joint is serious. This kind of joint has a relatively poor ductility.