Performance of Concrete Coupling Beams Subjected to Simulated Wind Loading Protocols-Phase II

Wind design of buildings, unlike seismic design, is typically still based on prescriptive code provisions and essentially linear elastic response under ASCE 7 strength-level demands. This inconsistency in philosophy between seismic and wind design results in cases where wind loads control the design strength of the overall or some portion of the lateral system, resulting in significant flexural and/or axial overstrength and therefore greater capacities than needed to resist seismic demands-not only for energy-dissipating ductile elements and actions (fuses) but also for capacity-protected elements and actions. Although allowing modest nonlinearity in prescribed components (for example, coupling beams) in tall concrete buildings subjected to strong wind events is viewed as an attractive option, such an approach has been hampered in part by the lack of experimental data on the performance of key elements subjected to wind loading protocols. To address these issues, a two-phase research study was undertaken that involved testing eight 2/3-scale concrete coupling beams subjected to quasistatic, cyclic wind loading protocols. The focus of this article is on Phase II tests, which investigated the impact of loading protocol, type of coupling beam (reinforced concrete [RC] versus steel reinforced concrete beams) and epoxy injection repair. The test results indicated that, regardless of the type of loading protocol used, the beams performed well, with only minor residual cracks and no concrete crushing or spalling, or bar/steel section buckling or fracture.