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Cracking Concrete's Code
ScienceNOW Daily News ^
| 2 February 2007
| Robert F. Service
Posted on 02/15/2007 1:49:01 AM PST by neverdem
click here to read article
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1
posted on
02/15/2007 1:49:03 AM PST
by
neverdem
To: AntiGuv
2
posted on
02/15/2007 1:51:11 AM PST
by
neverdem
(May you be in heaven a half hour before the devil knows that you're dead.)
To: neverdem
"Estimates indicate that the energy used to create concrete accounts for 5 to 10 percent of the world's CO2 emissions. "Concrete Reabsorbs CO2
During the life of a concrete structure, the concrete carbonates and absorbs the CO2 released by calcination during the cement manufacturing process. Once concrete has returned to fine particles, full carbonation occurs, and all the CO2 released by calcination is reabsorbed. A recent study indicates that in countries with the most favorable recycling practices, it is realistic to assume that approximately 86% of the concrete is carbonated after 100 years. During this time, the concrete will absorb approximately 57% of the CO2 emitted during the original calcination. About 50% of the CO2 is absorbed within a short time after concrete is crushed during recycling operations. (Nordic Innovation Centre Project 03018).
3
posted on
02/15/2007 1:57:45 AM PST
by
endthematrix
(Both poverty and riches are the offspring of thought.)
To: neverdem
What an interesting article and link. Thanks.
4
posted on
02/15/2007 1:57:54 AM PST
by
grannie9
(Between slobs, dogs, and Englishmen, I'm always in hot water.)
To: neverdem
this new understanding could lead to novel forms of concrete Big deal. The mafia has been making shoes and overcoats out of this stuff for years.
To: Larry Lucido
LOL...Maybe they should consult some goombahs in Joisey for future applications.
6
posted on
02/15/2007 2:09:33 AM PST
by
gr8eman
(Everybody is a rocket scientist...until launch day!)
To: Larry Lucido
7
posted on
02/15/2007 2:12:58 AM PST
by
sit-rep
( http://trulineint.com/latestposts.asp)
To: neverdem
8
posted on
02/15/2007 2:21:40 AM PST
by
XR7
To: Larry Lucido
"The mafia has been making shoes and overcoats out of this stuff for years."
As well as caskets...I have no doubt that Hoffa is bridge support on some highway.
9
posted on
02/15/2007 2:32:34 AM PST
by
AlexW
To: Larry Lucido
10
posted on
02/15/2007 2:59:00 AM PST
by
zarf
(Her hair was of a dank yellow, and fell over her temples like sauerkraut......)
To: sit-rep
Hey! Guess we're both up early this morning.
To: neverdem
Seen quite a few laborers get hernias trying to move 2" slump concrete. Worked with a contractor a few times, over 25 years ago, who always poured with about an 11" slump. No idea how that worked out in the long run.
Been pouring for 30 years plus and 4" or 5" slump mud, has held up as well as anything anywhere else. Material varies widely and has much more deleterious effects than slump.
12
posted on
02/15/2007 3:45:17 AM PST
by
David Isaac
(Duncan Hunter '08)
To: Nailbiter
13
posted on
02/15/2007 4:02:30 AM PST
by
IncPen
(When Al Gore Finished the Internet, he invented Global Warming)
To: neverdem
Estimates indicate that the energy used to create concrete accounts for 5 to 10 percent of the world's CO2 emissions. Why is CO2 emission, or the lack of it, important? Antropogenic Global Warming is a myth.
To: agere_contra
CO2 is a pollutant. That's why plants love it so much.
15
posted on
02/15/2007 4:07:53 AM PST
by
Fresh Wind
(Vaclav Klaus: "A whip of political correctness strangles their voice")
To: endthematrix
I believe the greater long term impact on CO2 levels of from making concrete come NOT from the energy used to make the concrete itself, but rather the CO2 absorbing vegetation the concrete replaces.
To: neverdem
Interesting post. Concrete has always been excellent when in compression. The problem is in tension. If there are ways to change the molecular structure to compensate for this property it would certainly be a giant step forward due to having to compensate with steel reinforcement which is very expensive.
To: neverdem
Thanks for posting. I LOVE concrete.
To: AlexW
I have no doubt that Hoffa is bridge support on some highway. Noted Mafia hitman the "Iceman" says that Hoffa was shot, stuffed into the trunk of a Toyota that was subsequently sent to a car crushing plant. The car was crushed and melted in a furnace. Hoffa is a hood ornament somewhere....
19
posted on
02/15/2007 6:21:46 AM PST
by
Thermalseeker
(Just the facts, ma'am)
To: Thermalseeker
Recycling Hoffa's carbon footprint was easier when his actual footprint is much smaller ....
Seriously, I enjoy seeing any improvement in concrete's properties, but the problem will be "aging" the new research results to prove (beyond the shadow of a bridge!) that the "new" concrete can be safely and uniformly actually crushed and made in the field by real workers (not in one pound batches by PhD's), be shipped, poured and cast in the field by real construction crews, and then having the results last for 50 - 100 years after pouring.
It's easy to see the new particles/new methods failing under vibration or stress over time.
20
posted on
02/15/2007 6:28:21 AM PST
by
Robert A Cook PE
(I can only donate monthly, but Hillary's ABBCNNBCBS continue to lie every day!)
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