Shear-Critical Reinforced Concrete Columns under Increasing Axial Load.

Structural elements in old reinforced concrete (RC) frame buildings are often prone to shear or flexure-shear failure, which can eventually lead to loss of axial load capacity of vertical elements and initiate vertical progressive collapse of a building. An experimental investigation of shear and flexure-shear-critical RC elements subjected to increasing axial load is reported herein. The focus is on the effect of vertical load redistribution from axially failing columns on the nonlinear (pre- and post-peak) response of neighboring shear-dominated members. The test results along with an analysis of the recorded deformation, strength, stiffness, and energy dissipation characteristics shed light on the performance of substandard columns under constant and increasing axial load subsequent, or just prior, to failing in shear, thus providing useful insights into the assessment of existing RC structures. [ABSTRACT FROM AUTHOR]