Interesting, and thinner than I expected. In WWII, it was common to build
runways and taxiways out of unreinforced concrete. The engineers had
conversion charts that said if so think with so much rebar, then so think
with none. When I was working for the airplane factory we did certain kinds
of testing at a nearby former Naval Air Station (Yup in the middle of
Kansas) the Hutchinson Naval Air Station, which was a base for the navy
version of the B24, the one with the single tail. The son of a local rich
oilman bought it for residence and fun, he lived in the tower structure, the
actual glassed in part of the top had sofas around the outside (yes, this
was in the seventies when parties, sex and drugs happened) and several of
the attached buildings had his collections of various Italian supercars in
them. He rented out the place for us to test, and for gliders and skydiving.
Once while testing, we were constantly irritated by the noise of concrete
being broken up. He had contracted with a local concrete plant to sell them
runways for aggregate. Yes, noiser than jet engines. But the runways were
about one foot thick concrete.
-----Original Message-----
From: Jim Nichols
Sent: Thursday, February 18, 2016 2:19 PM
To: LUG@xxxxxxxxxxxxxxx ; Olympus Camera Discussion
Subject: [OM] IMG: Repair of WWII Concrete
I took a walk in the sunshine today at the local airport. Felt good!
This airport was built during WWII as an US Army Air Force training base
for B-24s, hence the concrete was very thick to withstand the wheel
loads. While much of it has held up well, places that received a lot of
traffic have developed cracks. A contractor has been hired to cut out
these broken areas and replace them with new concrete. ( It is
interesting to me that, while concrete made today in our area uses
crushed limestone as the aggregate, I have seen areas of the original
pours that used creek gravel, including a few mussel shells, as the
aggregate.)
This image gives an idea of the thickness of the original concrete.
http://www.gallery.leica-users.org/v/OldNick/Thick+Concrete+3162.tif.html
To tie the new to the old, the old concrete is drilled and rebar is
installed.
http://www.gallery.leica-users.org/v/OldNick/Drilling+for+Rebar+3163.tif.html
About half of this section has been replaced, as the crews work with
manageable pour sections.
http://www.gallery.leica-users.org/v/OldNick/Working+Concrete+3157.tif.html
The rotating mixer drum must be washed out after each pour.
http://www.gallery.leica-users.org/v/OldNick/Wash+Job+3161.tif.html
And then, the truck heads back to the plant for another load. Multiple
trucks were in use, to keep the job moving at a workable pace.
http://www.gallery.leica-users.org/v/OldNick/Going+to+Reload+3165.tif.html
Fuji X-E1 with Fujinon 35/2.0
Comments and critiques welcomed.
--
Jim Nichols
Tullahoma, TN USA
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