Anchorage to Concrete by Metallic Expansion Anchors

The behavior of metallic expansion anchors under monotonic loading is described on the basis of a large number of available test results. Expansion anchors loaded in tension will often fail in a rather brittle manner by pulling out a concrete cone. The corresponding failure load Fu is approximately proportional to f ct · 1 d 1,5 (fct = concrete tensile strength. Id = anchorage depth). Anchors placed too close to each other or too close to an edge produce a common cone failure or an edge failure respectively at correspondingly reduced ultimate loads. Assuming a 30 deg. failure cone, the actual behavior can be described with sufficient accuracy for practical purposes. If anchors are placed in cracks, the failure load will be significantly lower than for anchors installed in uncracked concrete, depending on the type and make of anchor and the crack width.