Quest for the Ultimate Anchor Bolt

[transmissiontowers]

Does anyone make a deformed bar re-bar anchor bolt out of a weldable grade steel like F1554?

I need to revise the design of all of our "standard" anchor bolts (from 3/4 inch to 3" diam) to meet current ACI 318 code embedment depth. We use A615 Gr 60 threaded re-bar for the diameters up to 2" and A193-B7 for 2" to 3". These bolts are used for many structures and have different sized vertical reinforcing bars in drilled piers and slab type foundations. I can understand the load transfer mechanism from the deformed bar bolts to the concrete and can follow the recommended ACI development length equations, but I have a harder time understanding how the headed smooth bar loads up the vertical reinforcing bars in the drilled pier. The length of the smooth bar should depend on the vertical bar size and how far away the smooth bar is from the vertical re-bar.

My solution would be a threaded deformed bar made from something like F1554 and it would be nice to be able to weld on it in case it got damaged and needed to be repaired in place by welding a new top to an old bolt.

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I have been called "A storehouse of worthless information" many times.

 

[Ron]

Take a look at Dywidag bars...

http://www.dywidag-systems.com/

 

[transmissiontowers]

Yes, I've seen these before but was looking for a regular style A-Bolt with UNC threads. The thing I dislike about the A615 threaded bar bolts is the uncontrolled carbon content and the inability to weld on them in case of some structure damage or corrosion down the line.

My ideal A-Bolt would be a 60ksi deformed bar in sizes up to 3 inch diameter that would be weldable.

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I have been called "A storehouse of worthless information" many times.

 

[bridgebuster]

transmissiontowers,

I've been called the same thing quite often. It's nice to have company.

 

[MikeDB]

I assume you are familiar with the #14J and #18J, Norsco 75S, made by Cargill Steel. These are the only two sizes made to my knowledge and are the only ones I would use for anchor bolts.

 

[transmissiontowers]

Yes, we used to use the 18 jumbo that could be turned down to a 2.25 inch nut and was 75 ksi, but the limit of 2.25 was too small for larger loads. I believe it had some minimum Charpy impact test requirement.

_____________________________________
I have been called "A storehouse of worthless information" many times.

 

[Dinosaur]

According to ASTM F1554-04,
Supplementary Requirements
S1. Grade 55 Bars and Anchor Bolts
This section speaks specifically to welding and recommends the Grade 55 variety. If the licensing requirements were not so strict, I would quote more of the ASTM for you. Good Luck.

 

[transmissiontowers]

For the bolts under 1.5 inches dia, we went with A706 60ksi deformed bar which is weldable. For the bolts 1.5 thru 3" we went with F1554 grade 105 to get the strength we had with A193-B7. I put an extra 2 feet of 8UN threads on the top to allow for future repairs by threading a sleeve nut on the undamaged piece. We are in a no seismic zone so the 105 ksi should be no problem.

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I have been called "A storehouse of worthless information" many times.