#14S Rebar? 1

[acbauer88]

We are performing a structural analysis on a very old reinforced concrete structure and in the drawings I ran into a "#14S" rebar. I think it is a "special" sized reinforcing bar. Anyone know of a good reference for the dimensions/steel grades that were used for these bars? A quick Google search says that these sized bars were added to the ACI code back in the 50's, but I was unable to find a good resource. The structure was built in the late 1960's if that helps.

Thanks a lot

Tony

 

[dik]

The bar may be 1-3/4" nominal diameter and they often had the rolling mill mark included with the number... other than that, no clue...

Dik

 

[asdf]

I have done a good number of rehab jobs, and have come across 14S a few times, best I recall they were 1 1/2" square bars. They appeared to be more like cast iron than rolled steel. No idea on proterties, but if you have to remove them, take a lunch bucket...

 

[asdf]

Or it could just be refering to ASTM A615 bars.

 

[acbauer88]

it looks like ASTM A408 is the governing specification. I'd really rather not buy a standard that was withdrawn in 1966....anyone know where to get a free copy?

 

[wannabeSE]

If I had to guess, "S" might stand for structural grade - Fy=33 ksi. CRSI published Engineering Data Report 48, Evaluation of Reinforcing Bars in Old Reinforced Concrete Structures. I could not find it on the CRSI web site. The report has a table of historic ASTM standards with years, grades and yield strength. You will probably find the report by searching the internet for "Evaluation of Reinforcing Bars in Old Reinforced Concrete Structures".

 

[denoid]

See the attached, from a 1956 CRSI book:

 

[acbauer88]

Wow, thanks a lot!

 

[paddingtongreen]

If memory serves me, they were 1 1/2 square bars, twisted to deliver a deformation.

Michael.
Timing has a lot to do with the outcome of a rain dance.

 

[dik]

The twisting also provided a mechanical deformation that incrased the strength a tad by strain hardening...

Dik

 

[acbauer88]

I'm assuming that the bars shown in my as-builts are the 1.693" dia. round bars shown in Denoid's CRSI reference. They aren't shown as square cross sections in the drawings, so I'm assuming they are round

 

[paddingtongreen]

Because of the twisting, they appear to be round in the end view as distinct from a cross section.

Michael.
Timing has a lot to do with the outcome of a rain dance.

 

[hokie66]

A structure built in the late 1960's in the US would not have twisted bars. The 14S bars were/are round. I think the "S" just meant they had to be Special ordered.