Two U.S. patents have been issued to Mineral Resource Technologies LLC (MRT), Atlanta, for a series of cement products using coal fly ash. Normally consigned to landfills, the ash residue from coal-burning electric utilities is being offered in three cement products -- a blended hydraulic form, a rapid (and intermediate) hardening version, and as masonry cement. In addition to environmental benefits, the materials also offer performance advantages over Portland cement, says the company.
"MRT Cement uses less water, virtually eliminating shrinkage or cracks," says Bob Styron, vice president of technical services. He also claims a lowered sensitivity to temperature changes makes the cement easier to use during cold weather.