Envelope #16: Do you know the difference between A706 and A615 bars?

Good morning! This is Back of the Envelope – the structural engineering newsletter that helps you become smarter each week.

Recently, a coworker shared a CRSI (Concrete Reinforcing Steel Institute) document called “Frequently asked questions about reinforcing bars.” (link)

Lots of really good info in there. My favorite one is about A706 bars vs. A615 bars.

We hear it all the time (and see it on the drawings) that for welded rebar and seismic applications, use A706, not A615…, but why?

The CRSI article explains it pretty well (it’s under the section “What is the availability and application of ASTM A706 reinforcing bars?”)

I’ll give you a CliffsNotes version in this email.

(Estimated reading time: 2 minutes and 18 seconds.)