Title: Shear-Friction Strength of Low-Rise Walls with 600 MPa Reinforcing Bars
Author(s): Jang-Woon Baek, Sung-Hyun Kim, Hong-Gun Park, and Byung-Soo Lee
Publication: Structural Journal
Appears on pages(s): 169-182
Keywords: cyclic loading; high-strength reinforcing bars; interface shear strength; low-rise shear walls; nuclear power plant walls; surface roughness; web-crushing strength
In thick reinforced concrete walls of nuclear power plants, the use of high-strength reinforcing bars for shear design is necessary to enhance the constructability. In the present study, low-rise walls with an aspect ratio of 0.33 were tested to verify the applicability of 600 MPa (87 ksi) bars to the shear-friction design. The major test parameters were the reinforcing bar grade, reinforcement ratio, surface condition and location of construction joint, concrete strength, and effect of flange wall. The test results showed that as the surface roughness was increased, the shear friction resistance of Grade 600 MPa (87 ksi) reinforcing bars was greater than that of 400 MPa (58 ksi) reinforcing bars. However, both 600 and 400 MPa (87 and 58 ksi) reinforcing bars did not reach the actual yield strength and design friction strength specified in ACI 318 (or ACI 349). On the other hand, the wall flange significantly increased shear-sliding resistance. Based on the test results, considerations for the shear-friction design of RC walls with high-strength reinforcing bars were recommended. Further, the web-crushing strength was evaluated for the walls showing web-crushing failure mode.