Foundation Bolt Strength

[CurlyDave]

Can anyone give me a pointer to the pull-out strength of a 5/8" x 12" foundation bolt, wet set in 2500 psi or 3000 psi concrete?

I thought this would be easy to find on the internet, but was I ever wrong.

This is the L-shaped bolt, sometimes called a mudsill bolt.

Thanks

Dave

 

[DanD78]

If the bolt is set around 10" deep in solid concrete I would think the bolt would give up before the concrete would pull out. The foundation bolts I have seen used are usually just soft bar stock threaded and bent. I don't have any numbers to back up my assumption.

What are you building?

Dan

 

[tlbuser]

Maybe this'll help
ASTM / ASME A/SA 193 / 194 GR. and
Bolting

Are you looking at load pathing instead of shear forces?

 

[JB4310]

Not to be wise, but why,

It's 100+ year old accepted practice. I don't think there's an inspector alive that would even look twice at a sill anchor bolt.

As long as there's enough of them, not sure on the standard spacing (4-6 ft?) but they're so overkill, never heard of one failing, even in a hurricane or tornado. Even at 10 ft spacing you could lift the entire foundation up before they would pull out.

Too many variables for accurate pull out specs I would think. or as mentioned bolt would fail before it pulled out.

There's a little info here if you can follow it. Don't know if it will help.

http://www.ci.sammamish.wa.us/files/document/4258.pdf

http://www.eng-tips.com/viewthread.cfm?qid=160677&page=17

JB.

 

[inveresk]

You can also increase the pull out strength by threading a couple of nuts followed by large diameter washers at 1/3 points along the bolt.

 

[Egon]

Welcome back Inveresk!

 

[CurlyDave]

Thanks guys.

I found what I needed here: STRUCTUREmag: Applying Appendix D of ACI 318

 

[JB4310]

Thanks guys.

I found what I needed here: STRUCTUREmag: Applying Appendix D of ACI 318

Dave,
As long as you can understand it

Once they start using letters in math, it's over my pay grade

JB.

 

[CurlyDave]

If you skip to the end there is a nice table that tells you bolt size and pull out force.

 

[timswi]

If you skip to the end there is a nice table that tells you bolt size and pull out force.

Hey Dave,

We still are curious about your concern in terms of the bolts. let's face it, if you get winds or storms hard enough to strain those bolts, I would think other things, like the roof would be gone and the nails would have pulled out of the studs. I guess the sill plate would be in tact though.