The hardest thing about concrete just might be the problem of how to make the ubiquitous building material in an environmentally friendly manner. Recent laboratory results at Princeton University indicate that the challenge of making greener concrete may eventually be cracked.
Concrete raises climate-change concerns because manufacturing its primary component, Portland cement, is responsible for as much as 8 percent of human carbon dioxide emissions. Even worse from an environmental standpoint, forecasters predict Portland cement production will double over the next 30 years.
Read more about this research on taking concrete steps toward lower carbon dioxide emissions here.