The erection of shear walls in concrete structures in one of the common method in order to resist under lateral loads which include wind’s load and seismic loads. The shear walls efficiency decrease in inverse relationship with increasing height of buildings and it causes more requirement of shear walls. Using coupled shear walls is the common strategy owing to avoidance of increasing the number of shear walls in buildings. Coupled shear walls decreases both lateral deformation and flexural moment in the structure. Two seprate and adjacent shear walls have flexural deformation. Spandrel beams close coupled shear walls behavior and lateral deformation to resist moment frame and shear deformation with transferring shear and flexural moment between two walls. It is shown that spandrel beam has a magnificent effect on coupled shear wall’s system.
The purpose of this research is investigating the effect of spandrel beams’ diagonal rebar on ductility of coupled shear wall, considering compression strength of concrete and shear wall’s height. Abacus software and finite element analysis have been used in order to obtain suitable results. The shear walls with high ductility in height of 4 and 7 stories were designed by American Concrete Institute guideline (ACI 318-14) and simulated in Abacus software. Diagrams of base shear-displacement for each model were obtained and parametrical analysis of diagonal rebar effect on shear walls’ ductility by considering strength of concrete has been done.
Analytical results indicate that designed spandrel beam without diagonal rebar reduces 4 to 16 percent of the series of coupled shear wall. Increasing concrete’s strength reduces relationship between diagonal rebar and ductility of shear wall. Another result which is observed is increasing the strength of concrete rises 12 to 28 percent of ductility of the series of coupled shear wall and this growth in observed more in the concrete with low strength.