Cyclic Loading Test for Reinforced Concrete Walls (Aspect Ratio 2.0) with Grade 550 MPa (80 ksi) Shear Reinforcing Bars

In shear design of massive walls in nuclear power plants, the use of high-strength reinforcing bars is necessary to enhance the constructability and economy. In the present study, walls with an aspect ratio of 2.0 were tested under cyclic lateral loading to investigate the effect of 550 MPa (80 ksi) bars on shear strength of slender walls. The test parameters were shear reinforcement grade, shear reinforcement ratio, and failure mode. Most test specimens failed due to diagonal tension cracking. The ratios of the test shear strength to ACI 349 prediction (that is, safety margins) were 1.48 to 1.83 and 1.18 to 1.46 for general and seismic provisions, respectively. The test results of walls with 550 MPa (80 ksi) bars were similar to those of walls with 420 MPa (60 ksi) bars: failure mode, safety margin, and average crack width. The test results and failure modes were confirmed by nonlinear finite element analysis results.