Interaction of Pre-Induced Damages along Main Reinforcement and Diagonal Shear in RC Members

Abstract

The mechanical interaction of pre-induced damage and diagonal shear was investigated with regard to corrosion cracks in concrete and rupture of the web reinforcement along the main reinforcement. First, localized corrosion cracking was produced in concrete around the mid-span of beams in both compression and tension fibers, and a mechanical interaction was no longer identified. Next, cracking occurred near the beam supports inside a shear span and around the anchorage zones of longitudinal steel. A diagonal shear crack was observed to meet the pre-existing cracking around the anchorage zones of longitudinal steel. Crack propagation into the anchorage zones resulted in significant decline in the overall capacity. On the other hand, the overall capacity could be maintained or even increased by keeping anchorage failure from occurring. Finally, RC beams with artificial defects in both concrete and web reinforcement over the whole shear span were tested. Damage around anchorage zones was concluded to play a critical role in triggering shear sliding failure in pre-damaged reinforced concrete.