Guidelines for Assessing CCPs in Pond and Landfills for Beneficial Use

The closing of hundreds of coal powered power plants across the U.S. combined with the use of additives for acid gas and mercury control is resulting in a new economic dynamic for quality coal ash used in concrete and cement applications. A drop in the density of ash sources and decrease in the quantity of quality ash is causing concern over future supply. Fly ash will, at least in some parts of the U.S., shift from oversupplied and underpriced to a more balanced value proposition. This will help spur the development of new supplies, including both export/import and most importantly fly ash stored in ponds and landfills. OPC concrete is the most important and valuable use for conventional fly ash. Fly ash improves strength, durability and resistance to chemical degradation of concrete, decreases water demand, and improves workability (EPRI, 2007). Among the environmental benefits of using fly ash in concrete are reduced carbon footprint and lower energy demand compared to the production of OPC. The performance of fly ash in concrete is well understood, and although other materials such as natural pozzolans are being proposed we see little impetus for substantial change in supply. The objective of the proposed study is to develop methods and procedures to assess the potential for any candidate ponded ash for utilization in the concrete and cement industry. Issues to be addressed include: sampling methodology and sample recovery requirements; sample characterization protocols and methodology; and quality standards, for both Class-F and Class-C ash-storage sites. In other terms, how do we sample, characterize and assure the quality or recovered ash for use as a pozzolan in concrete.