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What is the required embedment for development of reinforcing steel?

Posted by Tmorfordover 6 years ago
What is the required embedment for development of reinforcing steel?

I attended the fundamentals of post-installed Reinforcing Using Qualified Adhesive Anchor Systems this morning and had a question in relation to it. In the Q/A session there were several questions on development length and some really deep embedments for the development of rebar were discussed and I want to make sure I am understanding something correctly. If I am using the development provision of the ACI code (aka I want to full develop my reinforcing bar) I need to specify my post installed bar be embedded the length per ACI code is that correct? In discussing this with my coworkers, most thought there was some advantage to using post-installed rebar that allows for a shallower embedment some of the products we use (non-Hilti) specify just 10x bar diameter....so quite a bit different than the development length.

anchor development length

1 Reply
Posted by Bryan Johnsonover 6 years ago
Hilti Verified

Tmorford,

You are correct, in that if you are using the rebar development provisions outlined in ACI 318 Anchoring-to-Concrete, you will need to use the development length equation to calculate the embedment required to develop the yield strength of the bar. Typically you will see large embedment depths that will be no shorter than 12 inches, as seen by using the development length equation. Unfortunately, I wouldn’t be able to comment on the performance of another manufacturer’s products; however, post-installed rebar allows for extension of existing reinforced concrete members without having to remove chunks of the concrete, core and grout, or demolish an entire wall. For more information you can access Hilti’s Post-Installed Reinforcing Bar Guide (https://submittals.us.hilti.com/PIR_Guide/#1) or Hilti’s Rebar Design Center (https://www.hilti.com/content/hilti/W1/US/en/engineering/design-centers/rebar.html) for additional information.

Regards,

Bryan

Adhesive,Rebar,Development Length