PEMB - Anchor Bolt Jargon

[JoelTXCive]

I have a set of sealed shop drawings for small steel canopy.

The PEMB engineer has provided column loading data. Our loads are small. The greatest one is 3 kips uplift; and less than 0.5 kip horizontal.

Since we designed the slab, I still want to put into the Hilti software to doublecheck.

Below is what the PEMB engineer has provided for anchor bolts.

Does anyone know what 'Bend Length' is? Embedment? (a reference to older "L-Bolts" versus hex head?)

See below:

Thank you in advance.

 

[dik]

From my Project Notes...

-[EOR SHALL CONFIRM] THREADED ROD SHALL CONFORM TO ASTM [A307, GRADE A | F1554, GRADE 55 S1 | CSA G40.21-300W].
-ANCHOR RODS SHALL BE SET BY MEANS OF A TEMPLATE.
-EOR TO CONFIRM ANCHOR RODS ARE ‘L’ TYPE, WITH A LENGTH OF 1’-4”, A 3” HOOK, AND A THREADED 4” PROJECTION WITH A HEAVY HEX HEAD NUT AND WASHER TOP. EMBEDMENT SHALL BE 1’-0”.

If you use A307, make sure you spec that it has to be weldable.

Rather than think climate change and the corona virus as science, think of it as the wrath of God. Feel any better?

-Dik

 

[phamENG]

Joel - haven't seen it, but my gut instinct is the return/small leg in the 'L' bolt.

 

[JoelTXCive]

Thank you Dik & Pham.

I agree with ya'lls comments....I think the PEMB Engineer is saying he wants 3" on the outstanding leg of the bolt; and that he wants a 2.5" projection out of the slab for the bolt.

The PEMB is not saying anything about embedment or anchor design, which will be my responsibility.

As a sidenote: I'm fine with the 'L-bolts', but I thought research had shown you get the same breakout and pullout capacity from bolts with an embedded hex head.

 

[dik]

On my own projects, I always use headed ARs, I don't use 'L' or 'J' type ARs... I haven't for decades.

Rather than think climate change and the corona virus as science, think of it as the wrath of God. Feel any better?

-Dik

 

[dik]

I just spec them for my projects... that's all I can do... and use ASTM1554 Grade 55S1... I like anchor rods to be weldable. I've encountered too many problems where it would have helped.

Rather than think climate change and the corona virus as science, think of it as the wrath of God. Feel any better?

-Dik

 

[Kuhladula]

It's the standard return leg length of a J-bolt for people using MBS software in the PEMB industry. You can likely ask the engineer if that value is truly required because MBS only outputs foundation loads. I've got that spec and the projection length turned off because of receiving that question a couple of times.

 

[Ron247]

I think bend length is the length of the 90 degree "hook" at the bottom.
Embedment is usually by the foundation engineer. PEMBs tend to give diameter, quantity and pattern but not embedment.

Projection is distance from finish floor to top of anchor bolt.

They probably still reference hooked bolts because PEMB anchor bolts typically are not highly stressed.

 

[SandwichEngine]

I can confirm 100% that the bend length is the horizontal leg of the old style L-bolts. I've used the program that exports that exact table and bend length is automatically generated unless you take it out. If they are supplying the anchor bolts, I'd require them to use headed anchors since hooked bolts have been removed from the concrete code due to problems. Also will need to tell them embedment depth. If they're not supplying them, and they probably aren't, you just need to make sure you're ok with the grade, diameter and placement.