Cyclic Loading Tests for Shear Strength of Low-Rise Reinforced Concrete Walls with Grade 550 MPa Bars

In the construction of nuclear power plants using massive walls, the use of high-strength reinforcing bars for shear design is necessary to enhance the constructibility and economy. In this study, low-rise walls (aspect ratio of 1.0) with Grade 550 MPa (80 ksi) reinforcing bars were tested to investigate the shear capacity and deformation capacity under cyclic loading. The test parameters were the grade of horizontal reinforcement, concrete strength, web bar ratios, use of boundary hoop, shape of cross section, and failure mode. The failure mode of the walls with 550 MPa (80 ksi) bars was diagonal shear cracking, followed by web crushing, which was the same as that of the wall with 420 MPa (60 ksi) bars. In the shear failure mode specimens, the ratio of the peak shear strength to the prediction of ACI 349 was 1.33 to 1.99 for the shear provision and 1.27 to 1.73 for the seismic provision, respectively.