Scientists at the Polytechnic Institute of Tomar say by blending in the grains left over after beer is brewed, the humble red clay brick can gain an enhanced ability to trap heat without compromising strength, NewScientist.com reported Friday.
Bricks are often impregnated with polystyrene as a way to enhance their heat-trapping abilities, but European Union restrictions on carbon emissions have made it expensive to incorporate it and other synthetic materials into bricks.
Brewery grains produced in large quantities as a byproduct of commercial brewing -- a pulpy mixture usually used in animal feed or sent to landfills -- can be mixed into clay bricks to offer the same insulation benefits, the researchers said.
The grains make the bricks more porous so they trap more air, which increases heat retention, they said.
A clay paste containing 5 percent spent grains yielded bricks just as strong as the conventional type while reducing the amount of heat they lost by 28 percent, the researchers reported in the Journal of Materials in Civil Engineering.
That could be of considerable benefit to the brick industry, said John Sanders, a researcher at the U.S. National Brick Research Center at Clemson University.
"With the current concern for energy codes, I think the industry is open to change," he said.