AASHTO Shear Connector Design 1" Shear Studs

[SENK151]

Hello,

I am from Japan, and I am learning about AASHTO LRFD Shear Connector Design.
From FHWA shear connector design example, I understood that the typical shear stud diameter is 3/4" or 7/8".
However, in case stud number wants to be reduce for construction purpose, is it possible to use 1" studs, and does this fall under the requirements of AASHTO LRFD?

Thank you in advance!!

 

[STrctPono]

The 3 standard sizes for ASTM A108 welded shear connectors are 3/4", 7/8", and 1" diameters so no, there is nothing wrong with you using 1" studs. I am not aware of anywhere in AASHTO LRFD that limits the size of the shear connector that you use. So long as it meets the aspect ratio, min. and max. pitch spacing, embedment depth, clear cover, and fatigue limits then you are ok.

 

[BridgeSmith]

I also don't know of anything in the AASHTO spec that would preclude the use of 1" studs.

I would only caution that you should check with your fabricators to make sure they can weld studs of that size. It takes a massive amount of current to weld the automatically end-welded studs - about 1100 amps for the 3/4" studs and 1400 amps for the 7/8" studs.

Rod Smith, P.E., The artist formerly known as HotRod10

 

[SENK151]

STrctPONO,

Thank you for your comment. I just checked the AWS 1.5 Bridge Welding Code also. They mention in Standard Dimensions stud diameter of 1" too.
FHWA examples mention mostly 3/4" examples, I guess this is just the typical size.

Bridge Smith,

Thank you for your comment also. The welding current for each stud is a big point too. Even though using 1" studs is possible. It might be harder to find a fabricator that can do this, I will take this into consideration.

 

[BridgeSmith]

For bridge girders, 7/8" studs seem to be the standard now. I suspect there's a reason the 1" studs aren't commonly used.

Rod Smith, P.E., The artist formerly known as HotRod10

 

[dik]

Likely the sweet spot for strength and cost... with the added energy requirements for the 1" ones, the 7/8 may be more cost effective.

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

-Dik