N°207. 1991. Fastenings to Reinforced Concrete and Masonry Structures. Vol. 2

Modern fastening techniques are increasingly used for transferring concentrated loads into concrete and masonry structures. These include cast-in-place systems, which are positioned in the formwork before concreting, and post-installed systems, which are installed in hardened structural concrete or masonry. Despite the fact that many fastening assemblies are carried out every day in practice, knowledge within the engineering profession regarding their behaviour is generally rather limited. Furthermore, there is no universally accepted design method.

In this report, an attempt has been made to compile and compare the worldwide available results of experimental and theoretical investigations on the behaviour of fastenings in structural concrete and masonry.

The performance of different anchor types, including cast-in-place systems (e.g. headed anchors, channel bars) and post-installed systems (e.g. expansion, undercut, and bonded anchors, plastic- and powder-actuated fasteners), is presented both for uncracked and cracked concrete as well as for masonry. Different loading directions (tension, shear, and combined tension and shear, as well as bending of the anchor or base plate) and load types (static, sustained, fatigue, seismic, and impact) are considered. Failure modes and load–displacement behaviour are described, and the effects of the main influencing parameters such as edge distance, spacing, load eccentricity, and reinforcement are discussed. Furthermore, environmental influences (e.g. temperature variations, corrosion, ultraviolet exposure) and anchor behaviour in case of fire are addressed, as well as the influence of anchor loads on the strength of the structural member acting as the base material. Finally, the behaviour of concrete in tension and theoretical approaches for predicting anchor behaviour are reviewed.

The Task Group VI/5 has attempted to take into account all work published up to April 1991.

The report shows that many areas are reasonably well understood, for example the failure process and influencing factors in the case of steel or concrete failure under monotonic, sustained, or fatigue loading. However, in other areas further research is required, for example for fastenings under seismic excitation, fastening assemblies in fire conditions, and fastenings in masonry.

Based on this state-of-the-art report, a unified and consistent design method for fastening assemblies will be recommended, and measures to avoid reduction of strength in the structural member in which the fastening is installed will be proposed in a forthcoming report.