Numerical study on optimized application of engineered cementitious composites in RC coupled shear wall structures

Due to the superior tensile strain -hardening and multi -cracking properties, engineered cementitious composites (ECC) can be adopted in reinforced concrete (RC) shear walls and coupling beams to improve the seismic performance and damage tolerance with simplified reinforcement details. This study numerically investigates the optimized application of ECC in coupled RC shear wall structures based on refined two-dimensional finite element models incorporating constitutive models of ECC and concrete for nonlinear shear behaviors. The balance between cost and performance is adequately considered from the material, member, and structural levels. At the material level, the reasonable tensile properties of ECC are suggested based on the parametric analysis of coupling beam and shear wall specimens. At the member level, the effect of diagonal bar ratios on the seismic performance of coupled walls is investigated to propose reasonable diagonal bar ratio of ECC coupling beams. Finally, at the structural level, nonlinear dynamic timehistory analysis of a typical 11 -story coupled wall structure based on practical engineering is conducted to investigate the influence of the application ranges of ECC on the seismic performance of the wall system. The damage indexes, including story curvature and crack width, are analyzed and compared. Based on the analytical results, recommendations related to some key issues on the application of ECC in traditional RC structures are provided, including the application range and tensile properties of ECC, as well as the reinforcement details.