Shear Friction with Mechanical Rebar Couplers 1

[umrce]

I have a phased project where I will have a cold joint in a beam so I am checking it for shear friction. Because of clearance issues at the joint we have to use mechanical couplers at the face where I'm checking shear friction. Will the couplers being present affect my capacity? I would assume not. If so, it should be noted that I cannot specify the type of connectors due to the client being a government entity that doesn't allow us to specify a company's product).

 

[briancpotter]

Can you provide a sketch?

Brian C Potter, PE

http://simplesupports.wordpress.com

 

[hokie66]

Shear friction depends on the development of the reinforcement which provides the required clamping action. So if the bars are developed in tension beyond the couplers, the couplers should have no effect. That said, I would alway locate beam construction joints near centre span, where the shear is lowest.

 

[TXStructural]

+1 for Hokie's post. Also specify sufficient surface roughness to engage the aggregate. Shear keys are ok, but will only provide shear area of the key itself (that is, the smooth surfaces on either side of a shear key will not provide shear resistance.)

 

[umrce]

Great news, thanks for the advice.