Effect of boundary confinement on ductility of RC walls

Abstract

This study addresses the effect of boundary confinement on the ductility of shear walls considering various rebar hoop details. Eight walls were tested under cyclic lateral loads. The major test parameters were the type of vertical reinforcement (seismic or non-seismic grade rebar) and the type and spacing of the confinement rebar details (special details (ACI 318-19) or simplified details). The test results showed that the use of confinement hoops increased the deformation capacity of the wall specimens. Although use of the simplified rebar details also increased deformation capacity, they were not as effective as the special details. Furthermore, as the concrete strength increased, the deformation capacity also increased. On the other hand, use of seismic grade rebar did not significantly affect deformation capacity because the walls failed due to concrete crushing in the compression zone before the vertical rebar experienced a large degree of inelastic deformation or tensile fracture. The axial strain capacity of concrete according to the confinement details was investigated based on existing and present test results. © 2020 Elsevier Ltd