https://ask.hilti.com/article/special-inspections-guidelines-for-post-installed-anchors/2jv5p4[/URL]]Proof loads – The establishment of proof loads should recognize the primary objective of proof loading as stated above, i.e., sufficiently high to provide assurance of correct installation but not so high as to result in damage. Given this objective, it should be clear that proof loads are set as a percentage of the tested tension capacity of the anchor, not the anchor design tension load. Historically, proof loads have been set at twice the allowable tension load. Given that the global safety factor used for anchor tension strength in allowable stress design has historically been set at 4.0 (inspected construction), the proof load represents approximately 50% of the mean ultimate anchor tension strength uninfluenced by edges, member thickness, etc. Note that, depending on the embedment to diameter ratio and the steel grade, this load might or might not subject the anchor to yield level stresses. For most mechanical anchor types using high-strength steels and typical embedment to diameter ratios (7 to 9), this is not a problem. Where lower yield steels are used, it should be verified that the proof loads do not exceed 80% of the nominal yield stress of the steel anchor components. Since the purpose of proof load is to verify proper installation, proof loading equipment may have load reactions close to the anchor but with sufficient clearance so any movement would be visible.
