Jim wrote,
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
[1]
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
[2]
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
[3]
The rotating mixer drum must be washed out after each
pour.
http://www.gallery.leica-users.org/v/OldNick/Wash+Job+3161.tif.html
[4]
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
[5]
Fuji X-E1 with Fujinon 35/2.0
Comments and critiques
welcomed.
................................................................
It
has held up to heavy traffic very well.
These days there are some
nearly magic alternatives to steel reinforcing.
One I know of and have
used is called "micropoz", a pozzolan material.
Varying the amount added
can increase the load-bearing strength of poured concrete surfaces from
the typical 17 MPa of a typical unreinforced domestic driveway, to well
over 40 MPa. see https://en.wikipedia.org/wiki/Concrete
Brian
Links:
------
[1]
http://www.gallery.leica-users.org/v/OldNick/Thick+Concrete+3162.tif.html
[2]
http://www.gallery.leica-users.org/v/OldNick/Drilling+for+Rebar+3163.tif.html
[3]
http://www.gallery.leica-users.org/v/OldNick/Working+Concrete+3157.tif.html
[4]
http://www.gallery.leica-users.org/v/OldNick/Wash+Job+3161.tif.html
[5]
http://www.gallery.leica-users.org/v/OldNick/Going+to+Reload+3165.tif.html
--
_________________________________________________________________
Options: http://lists.thomasclausen.net/mailman/listinfo/olympus
Archives: http://lists.thomasclausen.net/mailman/private/olympus/
Themed Olympus Photo Exhibition: http://www.tope.nl/
.
|