Steel "Unheaded" Stud Anchors in Composite Components

Question

Steel "Unheaded" Stud Anchors in Composite Components

TTomaz (Structural)

(OP)

13 Nov 23 17:20

Hi!

I am currently reviewing a proposal involving the use of A-36 "unheaded" stud anchors welded to a steel pile plug for concrete shear transfer, where tension is not anticipated.

As per my examination of AISC360-16, specifically in the I.8 Steel Anchors chapter, the documentation primarily addresses calculations for headed studs. The scope of AISC360-16 seems to be limited to headed anchors, and I am encountering a gap in guidance regarding the application of unheaded bolts in this context.

While the conceptual use of unheaded bolts appears reasonable for the intended purpose, I am seeking clarification on whether AISC360-16 provides any specific guidance for such scenarios.

I would greatly appreciate any insights or recommendations you may have on how to proceed.

dik (Structural) · Answer 1 · 2023-11-13 17:57:59

How long, and are they deformed?

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-Dik

WesternJeb (Structural) · Answer 2 · 2023-11-13 18:11:31

Is this meant to be a shear friction application? If so, then this will fall under ACI 318.

You say there is no tension, do you mean that there is no tension from the external force or no tension in bending?

Under your typical bending application (shear transfer), headed studs help to make sure the concrete to stud bond isn't the controlling factor and the concrete is held in place by the headed studs.

dik (Structural) · Answer 3 · 2023-11-13 18:49:09

That's what I was thinking...

-----*****-----
So strange to see the singularity approaching while the entire planet is rapidly turning into a hellscape. -John Coates

-Dik

271828 (Structural) · Answer 4 · 2023-11-13 22:51:07

Look at the AISC Specification Chapter I first paragraph. It doesn't cover this situation. I'd start searching scholar.google.com for this question. LOL

TTomaz (Structural) · Answer 5 · 2023-11-14 15:34:23

Thank you all for the replies. @WesternJeb, if this falls under ACI 318, then what is your opinion on what chapter should apply? The same as for those shear lugs in base plates? Chapter 17.11 of ACI 318-19?

TTomaz (Structural) · Answer 6 · 2023-11-14 15:39:40

Short update: maybe I was missing the concepts regarding the types of anchor studs, which can be whether headed or headless studs according to AWS D1.1.

It seems like DBA's (deformed bar anchor) complying with AWS D1.1 are headless studs type C cold worked low carbon steel fabricated under ASTM A496.

Just found this in this nice 2015 article Link

No information, however, regarding ASTM A36 carbon steel "fabricated" rods which are used as studs. I'm still stuck here.

WesternJeb (Structural) · Answer 7 · 2023-11-14 21:04:28

TTomaz, it depends on your application. I understand you have a steel pile plug, but which part? What forces are you intending to resist?

If it is a pure shear force being applied, then your strength would be based on basic material properties of your steel shear strength, weld strength, concrete breakout, etc.

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Steel "Unheaded" Stud Anchors in Composite Components