Earliest use of deformed rebar as property corner

A number of years ago I was part of a job in western Oklahoma that recovered several secondary tri-stations and BMs set by the USGS around 1900 to 1910. The stations still intact were 3/8" rebar set in concrete, inside a vertical 8" vitrified clay tile pipe. They were indeed deformed bars and the notes, from the era, referred to them as "iron pins". There were also one or two (approx.) 80d nails, referred to as "spikes" in the notes.

EDIT: I would bet money that surveyors have used rebar for "pins" since the time any survey crew was around any steel reinforced concrete projects...;-)

Many types of rebar throughout the ages, we used to run into twisted rebar on the east coast which was patented 1884 and used until 1940’s in some places.

See this book concrete

> What is the earliest use of deformed rebar as a property corner in your locale?
There is no doubt that in the Portland area, prior to 1944 (when Oregon's recording and Surveyor Licensing law kicked in), pipes were much more common than pins when a permanent monument was needed. That and Model T axles.

What does "deformed" rebar mean? (I know what rebar is)

> What does "deformed" rebar mean? (I know what rebar is)
It's rebar. The "deformed" part comes from the process of getting those ribs pressed into it.

more rebar info

page d-4 this doc powerhouse

I think Kent Mc Had some good info on this too.

I HAVE found sorry old half gone rebar, in rock piles, and REPLACED it with a more modern and less rusted pc of rebar.....

Usually the associated plat though tells: Fd ancient rusted pin, not much left of it, replaced with 1/2" x 30" rebar and cap.....

But it is possible that somebody rehabbed an old pin....

N

> What is the earliest use of deformed rebar as a property corner in your locale?
>
> This is why I ask...
>
> We are evaluating two different rebars that we found near the locus of the center one-quarter of a PLSS section.

The very first thing to do is to measure the distance between the deformations (transverse ribs) on the bar and determine its nominal diameter. The ratio of deformation spacing to bar circumference changed in 1947 as did the distance that the deformations protruded.

Change in rebar deformations

That simple evaluation will date the bar itself as having been made before or after 1947. Once you've identified which side of 1947 it falls, there are other clues to examine the bar for.

Excellent! Thank you!

Side note (hijack)
Kent,
Did you ever determine the source of Logan Pearce's blade?
DDSM

> Did you ever determine the source of Logan Pearce's blade?

Some feller in Arkansas sent it to me. :> (There are some high-strength rebars made with a higher carbon alloy preferred by the knifemakers.)

Funny! The southeast corner of the section in question was once monumented with an axle.

I am assume that calipers might be the best tool to get an accurate measurement of the nominal diameter and the depth of the deformations?

> Funny! The southeast corner of the section in question was once monumented with an axle.
I have been told that the axles on Model T's broke easily and it was a common shade tree repair.

deformed rebar

> What does "deformed" rebar mean? (I know what rebar is)

> Funny! The southeast corner of the section in question was once is still monumented with an axle.

deformed rebar

Deformed AND bent!

> I am assume that calipers might be the best tool to get an accurate measurement of the nominal diameter and the depth of the deformations?

An ordinary tape ought to be good enough to measure the bar diameter, I'd think, but you could use calipers if you need to take particular care in documenting the characteristics. As for the deformations, the spacing is the key fact. Laying a slip of paper over the side of the bar and making a rubbing of the pattern of deformations over half the bar or more with a stick of graphite is one way of documenting the spacing and pattern.

I'd have to dig out the ratios, but the older spacing is quite wide and the deformations are typically significantly shallower than those of contemporary bars of the same nominal size. Depending upon what size the bar is and the state of corrosion, you might be able to measure the height of deformations with a coin laid up against them.

If the bar is something from 1910, it most likely won't resemble a modern rebar very much at all when you start to examine it carefully. It shouldn't be a close call.

If you have the option of extracting the bar to examine it full length before replacing it, take care to check for grade marks and mill marks. Those are also clues that would eliminate many early dates for the origin of the bar.

[msg=80029]Rebar Trivia for Fun and Profit! [/msg]

Thanks Kent!

I appreciate the advice. I have a little time next week to reference and dig out the rebar in question. It is in the bank of a canal. If it isn't the center quarter per the plat I would like to see if there might be a rebar a little deeper down closer to the existing grade before the construction of the canal in the 1940s. There is a possibility it is surface reference to the original.

The other rebar (set in 1975) has been used as the center quarter (by less than a dozen surveyors). This other rebar (the one I want to research further) first appeared in the record in 1998 (unless of course it is the original per the plat and everybody just missed it).

Thanks for the link to your previous thread on this subject. I tried to find it by hadn't located it yet.

Should be fun!