Performance of Ordinary C-Shaped Reinforced Concrete Structural Walls Subjected to Wind Loading Protocols

Building design in ASCE/SEI 7 for extreme wind loads is based on elastic behavior, which eliminates the need to develop special detailing and capacity design rules to account for nonlinear responses. Recently, ASCE published a Prestandard for Performance-Based Wind Design that would allow modest nonlinear responses under wind loading to reduce construction costs while maintaining equivalent structural performance and safety, and address unintended negative impacts of wind design on buildings that are located in areas with both extreme wind and seismic hazards. Wind forces tend to have the greatest impact on taller buildings, where it has become common to utilize reinforced concrete core walls to resist lateral wind and seismic forces. Therefore, a study was conducted to investigate the performance of four large-scale reinforced concrete walls with C-shaped cross sections subjected to a biaxial wind loading protocol (WLP) followed by a seismic loading protocol (SLP). Prior to the wall testing, beam testing was conducted under WLPs to develop design requirements for lap splice lengths above the wall–foundation interface. The wall test results indicate that current ACI 318-25 detailing requirements are adequate for the wall with longitudinal reinforcement ratio (ρl) of 0.75%, which completed the WLP without noticeable damage or strength loss; however, for the walls with ρl of 1.5%, additional detailing at flanges edges may be needed to limit damage due to concrete crushing and longitudinal bar buckling, depending on the level of axial stress induced at the flange edges under biaxial loading. Based on the test results, strain acceptance criteria are recommended.