PennDOT's 'Green' Fly Ash Efforts

 (Aggregate Research 5-26-09)  PennDOT Assistant Construction Manager Michael McCart, it's a way to make roads, sidewalks and bridges stronger and longer-lasting, thanks to growing attempts to reuse it and other industrial wastes in making concrete. Concrete used for roads and buildings is a combination of stone, sand and binding agents -- usually a mix of lime and silica called portland cement -- that create chemical reactions and bind together when mixed with water. Because fly ash from power plants and ground-up slag left over from the steelmaking process can replace some of that cement and make the final product stronger, PennDOT is considering making their use mandatory.