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Installation of anchors when reinforcement is present

Posted by Zachary VanLemmerenover 7 years ago
Installation of anchors when reinforcement is present

*Posted on behalf of a Hilti customer:

Can you address installation with reinforcing present, especially ties that provide containment and prevent blowout scenarios (eg #4 ties at 2" )c/c)?

ACI,anchors

1 Reply
Posted by Bryan Johnsonover 7 years ago
Hilti Verified

Dear Customer,

thank you for your question. For installation of post-installed anchors where reinforcement may be present, ACI 318 does not currently address the possible transfer of forces between post-installed anchors and the existing reinforcement. With cast-in-place anchors, designers are able to design in a way that allows for them to also design anchor reinforcement (see ACI 318-11 D.5.2.9 and D.6.2.9 for example) which allows the designer to then ignore concrete breakout calculations. Because there are no design provisions or test data available to justify that post-installed anchors installed near existing reinforcement can transfer forces similar to anchor reinforcement, it is up to the designer to make that engineering judgement. It is more conservative to assume that no forces are transferred into the existing reinforcement as post-installed anchors are typically tested in unreinforced concrete during product data development. Please feel free to reach out any time, if you need additional information.

All the best
Bryan