New cement cuts greenhouse gases by 90%
Cement made from 'fly ash', a byproduct from coal-fired power plants, has a remarkably lower carbon footprint, recycles industrial waste, and is more durable.
By Bryan NelsonTue, Sep 29 2009 at 3:43 PM EST
12
CONCRETE: A 5,000 lb. geopolymer concrete block cast using fly ash. (Photo: Courtesy of Dr. Erez Allouche/Louisiana Tech University) Green cement? Given that the concrete industry is single-handedly blamed for 5 to 8 percent of all human-generated atmospheric CO2 worldwide, the notion may seem like an oxymoron. But researchers at Louisiana Tech have invented a remarkable new material which could cut greenhouse gas emissions from cement production by 90 percent.
|
WorldShares lets you earn donations for your favorite nonprofit. Earn up to 20 points now.
Learn More |
Earn Points
What's this? |
The new material, inorganic polymer concrete (geopolymer), utilizes "fly ash", a substance which is one of the most abundant industrial byproducts on earth, as a substitute for conventional Portland cement.
Not only does the new material recycle waste that would otherwise take up hundreds of thousands of acres used for disposal of coal combustion products, but geopolymer concrete features greater corrosion resistance, substantially higher fire resistance (up to 2400° F), high compressive and tensile strengths, a rapid strength gain, and lower shrinkage.
And perhaps most importantly, the new material has the potential to reduce greenhouse gas emissions by a whopping 90 percent over Portland cement. The key to its lower CO2 emissions is its significantly longer life cycle, capable of design life measured in hundreds of years instead of decades.
Since Portland cement is one of the most widely produced man-made materials on earth -- currently toping 2.6 billion tons per year worldwide and growing at 5 percent annually -- finding and using a greener cement is absolutely necessary if our global carbon footprint is going to be curbed.
This innovative technology definitely deserves its 'green' label. If you're interested in learning more, the research will be presented at Louisiana Tech's Energy Systems Conference on Nov. 5 at the Technology Transfer Center in Shreveport.
 WorldShares
lets you earn donations for your favorite nonprofit. Earn up to 20
points now.Learn More Earn Points
|
CLOSE
link:
link:
Comments
Jesse Blenn
12/03/2009 21:43 PM
The cement is only a part of concrete. The rest is usually sand and gravel filler. I have experimented a bit with using CARBON, that is charcoal as the filler. Specifically I used rice husk charcoal, here sold for use as a medium for growing hydroponic lettuce. It is very fine and replaces sand, with the final conrete weighing about half as much. Larger charcoal pieces could easily replace gravel and rocks and likely give an even higher weight savings.
I did find that due to the.... More
Martin
11/24/2009 00:36 AM
I have been using fly ash cement for several years now. It is not added to Portland Cement, it is a Portland Cement replacement, thus the 90% fly ash claims. I am using less virgin product, making use of a waste product that would be sitting in a landfill all while producing a much stronger building system. Our structures are fire resistant, moisture resistant, termite resistant and more affordable. Try it before you make negative comments.
Karl
10/30/2009 16:11 PM
Fly ash concrete has been around for more than a decade and by most calculations reduces the embodied energy of concrete by 25-50% (depending on what percentage is used). The whopping 90% claim comes from factoring in a longer life cycle, which doesn't own up to the reality that most buildings (whether they use fly ash or not) won't be around longer than 50 years.
Don't get me wrong - the material is great, but that 90% claim is confusing. True in theory. False in practice.
Uncle B
10/30/2009 13:14 PM
This suppoerts the Status Quo of a very unsustainable American dream! Fvcking follies! We need Super-insulation, and radiation free power sources a total paradigm shift convulsing our very existance, they give us concrete! Goddammit! Think survival, think vegan, think no oil - tomorrow! The Chinese Yuan about to bid against the great hulking American Neanderthals depleting dollar! You give us expensive concrete, that needs Fly Ash! are you kidding me? The great American neanderthal, facing.... More
D.C.
10/07/2009 15:46 PM
http://pubs.usgs.gov/fs/1997/fs163-97/FS-163-97.pdf
Coal ash isn't any more radioactive than other common rocks such as black shale and phosphate rock. If much less coal could be burned for energy to make the cement, then less coal ash and other pollutants would be released into the atmosphere.
Guest
10/07/2009 03:03 AM
What about high levels of fly ash radioactivity? How will it affect live creatures living in "green" cement buildings? And is production process going to be dangerous for people living in close-by areas - fly ash dust inhaled is much more hazardous than just lying in heaps.
LauraB
09/30/2009 12:08 PM
I love to hear how we can use anything that would normally just sit as waist!
Sean Roberts
09/30/2009 11:58 AM
I agree with "Taking it all in" -- legitimate question about cost, but we need more options available to make a difference.
creeshaw
09/30/2009 08:39 AM
This is not that new and it all depends on the chemical nature of the Ash itself combined with the various chemical and polymer admistures required to make it work when combined with portland cement to gain the higher strengths. There are numerous materials which are cementitious - ash is definately a good one. The goal is to reduce the amount of portland cement used while still achieving high strengths and workability
Travis
09/29/2009 21:50 PM
Cost is one good question. Other good questions for wide spread use would include: What is the energy cost to produce and transport the material, are there any special conditions need to actually install it in buildings, sidewalks, etc ..., would new equipment be needed to put it into use.
As or what concrete "wins", given the large scale use of concrete I think there is plenty of room for multiple options that use up waste.
Anonymous
09/29/2009 18:09 PM
But how much does it cost?
Elizah Leigh
09/29/2009 17:41 PM
This is almost as cool as Henry Miller's recycled plastic concrete http://bit.ly/28luqS, but Miller wins (at least in my book) since his efforts could potentially torch through a great deal of landfill plastic.
