Hollowcore Anchor Capacity 1

[Baffled Engineer]

Hello,

I'm working on a post-installed roof anchor to be grouted in a hollowcore cell as shown below.
The proposed detail would include a 15M bar reinforcement about 26" long into the grouted cell.

Does anyone have experience with calculating the concrete breakout capacity for this configuration?
Will the breakout cone develop at the typical 35-degree angle around the anchor / anchor group?
Or, would the grouted cell shear through the edges, or can the 35-degree breakout cone initiate around the grouted cell instead?






Thank you!

 

[Baffled Engineer]

 

[bones206]

Spancrete has a research tech note on headed stud anchor capacity. I’ll try to dig it up.

 

[bones206]

I posted a link to the research notes in this thread: https://www.eng-tips.com/threads/spancrete-research-notes.518393/

This is the specific one I was referring to:

 

[Baffled Engineer]

Thanks. I wish they explained the failure mechanism a bit more in detail... but it gives me an idea of ultimate capacity at least.

 

[TRAK.Structural]

Through bolting with a plate on the underside of the hollowcore slab could be an alternative? Probably still want to grout some of the cells in the area, and maybe add bars if the slab needs it for flexure.

 

[MRob909]

In the past I’ve also considered a ‘block shear’ failure mode where the line is through the adjacent cell wall at the thinnest point.
I would also add plugs to your detail to avoid over/ under filling the cell. Consider a non shrink flowable grout as opposed to dry pack.

 

[Baffled Engineer]

Thanks that makes sense.