Hello,
I am designing some post installed rebar using the Hilti Profis Engineering suite.
I have two situations in the attachment, the only difference being the edge distance is
“infinity” in one of them and 14,900mm in the other.
However, there is a huge difference in the capacity, nearly 5x. Can anyone please explain how the calculations are being
performed here?
Hello Nabigh,
Thanks for reaching out to Hilti.
In this scenario which you've given us, the reason why the difference in results coming because Concrete edge resistance needs to be verified whenever there is edge distance regardless of how large the edge is.
Hence when you've selected infinite edge in Y+ direction edge breakout is not considered, only X+ direction concrete edge breakout check will be considered.
However, in the scenario where all edges are fixed, concrete breakout check is considered for both X and Y direction, and in this case Y+ direction concrete edge breakout check is governing, hence showing the failure.
Clause 4.2.2.2 of AS-5216 suggests that when an edge is greater than 10 hef or 60d (d=diameter of anchor) then we can consider our edge to be the infinite.
Since in your case edge distance is more than 10 hef and 60d, we suggest you consider infinite edge for this design case.
I hope this clarifies your question, if you have any additional query, please reach out to our engineering team using link below:
https://www.hilti.com.au/content/hilti/A2/AU/en/engineering/engineering-services/technical-advice-request-external.html”
If you require any further information, please do not hesitate to contact us.
Regards,
Ask Hilti team