Deformed Rebar Question

[albanyYEM]

I was on a site today where it was noted that rebar with two different deformation patterns were present. One set of bars has deformations perpendicular to the bar's long axis while the other bar's deformations are at a diagonal to the long axis. The contractor said that every time they attempted to field bend the first type of bar, it would snap. They contacted the supplier who said those bars with the perpendicular deformations were to be for straight bars only. This was the first I've ever heard of such a difference. Is this a thing? For what it's worth the "diagonal" bars bent just fine in the field.

 

[nackra]

CRSI reference:

https://www.crsi.org/index.cfm/steel/identification

 

[Lomarandil]

It doesn't surprise me that different deformation patterns exist.

I don't think that the bending of bars would be that significantly affected by the deformation pattern. I'd be skeptical of that material and want to test the perpendicular style bars to make sure they meet the expected ductility and elongation requirements.

----
just call me Lo.

 

[albanyYEM]

I was aware of different deformation patterns, but I had never heard of a performance difference between the two patterns shown (as in one is not intended for field bending). The material specification was met based on the mill certificate provided for the bar materials.

 

[Lomarandil]

Mill certs are only as good as the person who provides them. If this is an issue for you, you should be able to send a sample to a material lab.

----
just call me Lo.

 

[albanyYEM]

Agree, this is true. Thanks for your comments.