Experimental Studies of High Seismic Performance Shear Walls

Experimental Studies of High Seismic Performance Shear Walls

Past RC panel tests performed at the University of Houston show that reinforced concrete membrane elements under reversed cyclic loading have much greater ductility when steel bars are provided in the direction of principal tensile stress. In order to improve the ductility of low-rise and medium-rise shear walls under earthquake loading, shear walls have been designed to have steel bars in the same direction as the principal tensile direction of applied stresses in the critical regions of shear walls. This paper presents the test results of large-scale shear walls under reversed cyclic loading. Two types of shear walls were designed for the reversed cyclic tests, one is low-rise shear wall and the other is mid-rise shear wall. The height, length and width of low-rise shear wall are 1.4 m, 2.8 m and 0.12 m, respectively. The height, length and width of medium-rise shear wall are 4.2 m, 2.8 m and 0.12 m, respectively. In the reversed cyclic tests, steel bars are provided in the directions of 45 degrees to the horizontal directions in the low-rise shear wall and 65 degrees to the horizontal directions in the bottom part of the mid-rise shear wall, which is very close to the orientations of principal tensile direction of applied stresses based on the finite element analysis. The steel ratio in both perpendicular directions of the shear walls is 0.48%. For the reversed cyclic tests, the force-displacement hysteretic loops are presented. Based on the experimental results, the tested shear walls with steel bars close to the principal tensile direction of applied stresses have greater ductility than that of the conventional shear wall.