Sand bricks created in UAE lab

Orlando Crowcroft , July 22nd, 2010

A US professor is developing a technique to make bricks using a bacteria that is able to solidify sand.

Ginger Krieg Dosier, at the American University of Sharjah, uses alternating layers of sand and a solution containing urea, calcium chloride and the non-pathogenic Sporosarcina pasteurii to cause a chemical reaction that forms a solid brick.

Dosier estimates that if her method were to replace the current methods of making the 1.2 trillion bricks produced worldwide each year, it would reduce carbon emissions by 800 million tons annually.This is because her method eliminates the need to burn coal or other fuel to heat a kiln to 2,000° F, as is commonly required in clay-brick production.

Dosier, who taught herself chemistry with the help of mentors, now is working on controlling her bricks’ specific properties. Varying the process, she says, can produce bricks as soft as sandstone or as hard as marble.

“This summer I will conduct many tests on the bricks’ hardness, brittleness, water-resistance, freeze-thaw reactions and long-term weather resistance,” she told the Engineering News Record magazine. “The goal is to provide structural and performance properties similar to standard clay brick.”

She is now working on a method to make the bricks cheaper, so they can compete with clay bricks.

“One of the foremost goals of the research is to make the cost as low as possible. Right now, each [experimental] brick costs $2.70. My goal is to get down to less than 50¢ per brick, the same as standard clay brick.”

Dosier believes that bio-made bricks could eventually supplant more than just standard clay bricks. “I can see this method being used to replace [concrete] block, retaining walls, tilt-up construction, paving and walkway infrastructure, pre-cast units and water-related applications. Right now, the sky is the limit in terms of possibilities.”