Minimum Shear Reinforcement of Slender Walls with Grade 500 MPa (72.5 ksi) Reinforcing Bars

Abstract

For the shear design of rein forced concrete (RC) walls, ACI 318 requires minimum shear reinforcement ratio in the case of 0.5 phi V-c <= V-u < phi V-c, and the yield strength of shear reinforcement is limited to 420 MPa (60 ksi). In this study, to investigate the effect of Grade 500 MPa (72.5 ksi) reinforcing bars on the shear strength and minimum shear reinforcement of RC walls, slender walls (aspect ratio of 2.5) with Grade 500 MPa (72.5 ksi) shear reinforcement were tested wider cyclic lateral loading. The test parameters included the failure modes, the grade and ratio of shear reinforcement, concrete compressive strength, and axial compression. The test results of walls with 500 MPa (72.5 ksi) reinforcing bars were directly compared with those of walls with 400 MPa (58 ksi) reinforcing bars. Further, the test strengths were compared with the predictions by current design codes.