Influence of edge reinforcement on the concrete breakout strength of anchor channels close to the edge of a concrete member

Abstract

AbstractCurrent regulations for fastening systems such as anchor channels consider a reduction of the concrete edge breakout strength of 30% in cracked concrete compared to uncracked concrete. In case the concrete is reinforced, it is assumed that the capacity in cracked concrete can be increased up to the level of uncracked concrete. In specific, according to AC232, the presence of a straight edge reinforcement bar between the anchor channel and the edge permits to increase the concrete edge breakout strength compared to cracked unreinforced concrete by 20%. In case of edge reinforcement enclosed by additional stirrups spaced ≤100 mm, AC232 allows to increase the concrete edge breakout strength by 40% (same capacity as in uncracked concrete). No precise prescriptions on the geometry and the diameter of the reinforcement are given. Experimental investigations on the behavior of anchor channels loaded in shear toward the free edge in uncracked and cracked concrete have been performed with different layouts of edge reinforcement to verify the validity of the code provisions and to define boundary conditions for the geometrical dimensions and location of the reinforcement. All tests have been performed at the Institute of Structural Engineering at the University of Natural Resources and Life Sciences in Vienna.