In Appendix D of ACI 318-08, the strength reduction factor (φ) for tensile strength of mechanical anchors when the anchor is governed by concrete breakout, side-face blowout, or pullout strength varies depending on the anchor category. How do I determine what category the anchor I'm using falls into? Anchor categories are determined based on post-installed mechanical anchor tests described in ACI 355.2-07, "Qualification of Post-Installed Mechanical Anchors in Concrete (ACI 355.2-07) and Commentary."2 This document is like an ASTM Standard in that it covers the tests to be conducted and the requirements for determining whether a mechanical anchor is acceptable for use in uncracked concrete only, or both cracked and uncracked concrete. The tests for determining the anchor category are performed by an independent testing and evaluation agency. Anchor manufacturers that have performed the tests report the category in their technical literature.
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