Eco Factor: Recycled cement waste to replace lime used to strengthen soil.
Civil engineers at Purdue University and the Indiana Department of Transportation are teaming up on green projects around the state, including work aimed at saving taxpayers $300,000 annually by recycling a waste product from cement manufacturing. As waste sources are further developed, cement kiln dust could be used to replace 70 percent of the roughly 1 million tons of lime used on projects annually to strengthen soil so that it can support new pavement.
Based on 2002 production rates, Indiana cement plants conservatively generated about 30,000 tons of cement kiln dust each year. At cost savings of $10 per ton, this generates annual savings of at least $300,000. A test section with cement kiln dust was used for repairs to Pendleton Pike at Interstate 465 in Indianapolis in 2008, along with a traditional lime-modified section. The kiln dust showed comparable engineering results at lower cost.
Cement kiln dust is cheaper and represents a huge untapped green resource for highway projects. The material is especially cost-effective for contractors near Fort Wayne and in northwest Indiana because it is produced by manufactures in those regions, reducing shipping costs.
Via: Purdue University [Press Release]
