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.
CONCRETE: A 5,000 lb. geopolymer concrete block cast using fly ash. (Photo: Courtesy of Dr. Erez Allouche/Louisiana Tech University) Comments
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
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.
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.
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
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.
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.
I love to hear how we can use anything that would normally just sit as waist!
I agree with "Taking it all in" -- legitimate question about cost, but we need more options available to make a difference.
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
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.
But how much does it cost?
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.
