Innovation Challenge Spotlight: Bricks
The Innovation Challenge: Create a building product that is safe, healthy, affordable, effective, and designed to be returned safely to nature or industry after use. This blog, posted weekly leading up the announcement of the Innovation Challenge winners on November 15, spotlights the key issues with conventional building materials and how the ten finalists’ innovations stand out. This week, we focus on bricks.
Bricks are most commonly made from clay, which is molded and then fired in a kiln. They are very durable and have been used in buildings for centuries.
Unfortunately, the firing process is quite energy-intensive, giving the material a high carbon footprint.1 Burning fossil fuels to meet these energy requirements releases a host of other air pollutants, including SO2, NOx, particulate matter (PM), VOCs, and CO.2
Additional pollutants are released when naturally occurring chemicals in the clay reach high temperatures.3 For example, firing releases hydrogen fluoride and hydrogen chloride. These emissions can lead to acid rain and damage plant life, though it’s difficult to generalize the extent of the damage because the fluorine and chlorine content of clay varies.4
Innovation Challenge finalist bioMASON presents a brick that is “grown” instead of fired. A bacterial byproduct cements sand particles together to form a durable matrix. Because high heat is not required, these bricks have a much lower embodied energy and emissions profile while still having the positive environmental attributes of conventional bricks.
1 Greenspec. (2013). Bricks: Fired/unfired clay, reclaimed & calcium silicate. Retrieved from http://www.greenspec.co.uk/bricks.php
2 Venta, G. P. (1998). Life Cycle Analysis of Brick and Mortar Products. The Athena Sustainable Materials Institute. Retrieved from http://calculatelca.com/wp-content/themes/athena/images/LCA%20Reports/Brick_And_Mortar_Products.pdf
3 European Bank for Reconstruction and Development. (Date Unknown). Sub-Sectoral Environmental Guidelines: Brick Manufacture. Retrieved from http://www.ebrd.com/environment/e-manual/subsecs/bricks.pdf
4 Venta, G. P. (1998). Life Cycle Analysis of Brick and Mortar Products.