Coating concrete destined to rebuild America’s crumbling bridges and roadways with some of the millions of tons of ash left over from burning coal could extend the life of those structures by decades, saving billions of dollars of taxpayer money, scientists reported in Anaheim, California at the 241st National Meeting & Exposition of the American Chemical Society on March 29.
They reported on a new coating material for concrete made from flyash that is hundreds of times more durable than existing coatings and costs only half as much.
Study leader Charles Carraher, Ph.D., explained that the more than 450 coal-burning electric power plants in the United States produce about 130 million tons of “flyash” each year. Before air pollution laws, those fine particles of soot and dust flew up smokestacks and into the air. Power plants now collect the ash.
“Flyash poses enormous waste disposal problems,” Carraher said. “Some of it does get recycled and reused. But almost 70 percent winds up in landfills every year, where space is increasingly scarce and expensive. Our research indicates that this waste could become a valuable resource as a shield-like coating to keep concrete from deteriorating and crumbling as it ages.”