Green Bricks?
by Jeremy Elton Jacquot, Los Angeles on 05.31.07
In the fight to save energy and combat emissions, every little bit helps: even the lowly, mass-produced clay brick. Over nine billion bricks are churned out annually, each at great cost to the environment (making cement for concrete bricks emits thousands of pounds of mercury into the air while baking them discharges a diverse array of pollutants). Henry Liu, a 70-year-old retired civil engineer, decided he could improve upon this wasteful process.
He came up with the concept for a better brick, one that would put to use fly ash, a waste product commonly issued from coal-power plants, and that would prove just as durable as regular clay bricks. Because they solidify under pressure instead of high heat, building his bricks would help save energy and would cost at least 20 percent less. In addition, their molded shape, which gives them a smoother and more uniform appearance, would help cut down on bricklaying time and work.
Having spent most of his professional career working with hydraulic presses, Liu jumped at the chance to try out his hydraulic rig when a power plant gave him some free fly ash to use in 1999. After mixing the powder with water and pounding it with 4,000 psi of pressure, he let the mixture set for two weeks and obtained blocks that were as strong as concrete. He found that their strength derived from the concrete's ability to stick together with cement, specifically the calcium oxide present within the material that would bind with surrounding elements when it reacted with water.
The hard part for Liu was meeting federal safety standards, which took him another eight years and over $600,000 from the National Science Foundation (NSF) after his original discovery. In order to reach the goal of surviving 50 cycles of freezing and thawing (a test he initially failed when his bricks broke after eight), he incorporated an air-entrapment agent, a chemical often used to strengthen concrete bricks by preventing the infiltration of water into the material, into his mixture.
He hopes to license the bricks and start selling them next year, a step that may not prove popular with all potential clienteles. "The people who buy bricks will definitely be interested," says Pat Schaefer, a sales manager for Midwest Block & Brick. "But I don't see the brick companies liking it at all."
See also: ::Ask TreeHugger: Nearby Construction and Pollution, ::Sustainable Construction at Construmat: the R4House, ::BBC Enthuses about Hemp, Straw and Lime for Construction, ::TreeHugger Picks: Straw Bale Construction, ::Building Green: Energy Efficiency and Aesthetics From The Same Materials (Part 8), ::In praise of Brick Shithouses
Bricks ARE green when they're re-used. Antique bricks are often more expensive when new ones! Any green brick would have to be able to re-used...
He should team with with some material scientists to imrove upon these bricks. Although I agree re-used bricks are the greenest choice. People are always giving away bricks on craigslist.
If a waste product can be used.Is that not good.No landfill/trash.
Every brick I've seen is reusable. It's whether or not people take the time to bring a structure down as carefully as they put it up. Most companies just take heavy machinery to the walls and knock them down. I like the idea of recycling bricks, but I think it'll take a law to force people into doing it on a large scale here in the US.
As for the fly ash, I'd like to find a way to certify that it came from a coal burning plant that dealt with it's carbon emissions. If we're going to be calling them green bricks we ought to ensure that as much of the process is green as is possible.
It would be great if they were actually colored green, like the ones pictured above. Just a little way of advertising that your bricks are green...
Be careful how you read this article. The environmental nightmare is not about clay brick (the brick we are used to) - it's about concrete brick. Clay brick use one of the most abundant materials on earth, clay, mix it with water and bake it. Although the brick are fired to over 1,500 degrees F, the process is very efficient.
And as commented by other posters, clay brick has been reused for many new projects.
Brian Trimble
Brick Industry Association
www.gobrick.com
These are not bricks they are more similar to precaste concrete block. A brick must be sintered not pressed and cured. The color will last 5 to 10 yrs and then fade. These bricks are not reusable.
The flyash used in these bricks is high grade class C, which a is commodity not a waste product. The most environmentally and financially efficient way to use this flyash is in concrete both as an additive in the cement productiona and again as an additive in the concrete mix.