Shear strength of an anchor post-installed into a hardened concrete member

Abstract

Literature has recently provided the analytical model that predicts the shear strength of the anchor embedded into masonry. It is apparent that this model does not apply to the anchor embedded into concrete, as the ultimate contact pressures are different. A gap in the literature was hence filled, but there existed a remaining gap. In order to fill that last gap, further research was done. This paper is herein an account of that work. The paper deals with the anchor post-installed by drilling into an already compact concrete structure, used to transmit applied loads from an attachment to the concrete, subjected to a force acting at the end that emerges from the concrete and orthogonal to the anchor (shear force with no axial force), with large clearance from the edges, either alone or with large clearance from other anchors. Being post-installed, the embedded part of the anchor is a straight shaft with no hook at the embedded end, and with no nuts, washers, or plates attached to the shaft. The paper presents an analytical model absent in literature prior to this study that predicts the maximum shear force the anchor can carry, thus called “shear strength” of the anchor. The assumptions of the analytical model were established from the results of a non-linear numerical model specifically constructed by the author. The predictive capacity of the analytical model and accuracy of its results were assessed and verified by experimental tests of real anchorages specifically designed and performed by the author. This paper also presents the numerical model and the comparisons of the analytical predictions to those experimental results, as well as comparisons to experimental results borrowed from literature and code provisions.