Flexural Behavior of Lightweight Aggregate Concrete Shear Walls with Boundary Element: Fid-Bau Portal

Flexural Behavior of Lightweight Aggregate Concrete Shear Walls with Boundary Element

Yang, Keun-Hyeok / Mun, Ju-Hyun / Oh, Na-Kyung

This study examined the effects of the unit weight of concrete ( $ω_{c}$ ) on the flexural performance of shear walls with different amounts ( $A_{s h}$ ) of transverse reinforcement in the boundary elements. Six shear wall specimens with barbell-shaped cross sections were tested up to failure under a constant axial load and cyclic lateral loads. Backbone curves determined using the cyclic lateral load–displacement of shear walls were compared with predictions obtained using the two-dimensional (2D) nonlinear laminar approach to examine the effect of $ω_{c}$ on the confinement pressure provided by the transverse reinforcement. The test results indicated that lightweight aggregate concrete (LWAC) shear walls exhibited a smaller displacement ductility ratio and cumulative work damage indicator than their normal-weight concrete (NWC) shear wall counterparts. The conservatism of the ACI 318-19 approach using the equivalent stress block for estimating the moment capacity of shear walls was somwhat affected by $ω_{c}$ or $A_{s h}$ . Meanwhile, the confinement by transverse reinforcement in the boundary elements tended to decrease with a decrease in $ω_{c}$ , which resulted in earlier damage to the longitudinal reinforcement and a faster reduction in the applied load at the post-peak performance for LWAC shear walls than for NWC ones with the same $A_{s h}$ . The current 2D nonlinear laminar approach can accurately estimate the overall flexural performance of shear walls made using different types of concrete.