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MPC Research Reports
Report Details

Title:Utilization of Wyoming Bottom Ash in Asphalt Mixes
Authors:Khaled Ksaibati and Shiva Rama Krishna Sayiri
University:University of Wyoming
Publication Date:Mar 2006
Report #:MPC-06-179
Project #:MPC-240
TRID #:01030692
Keywords:asphalt mixtures, asphalt pavements, bottom ash, cracking, falling weight deflectometers, field studies, fly ash, laboratory studies, pavement performance, rutting, statistical analysis, stripping (pavements), test sections, waste products


Coal ash is the portion of ash rejected by the stack and collected at the base as a waste product. Coal ash is comprised of bottom ash and fly ash. Fly ash accounts for 70 percent to 80 percent of total coal ash and the rest being bottom ash. Only 39 percent of bottom ash is utilized with the rest being disposed of in mined out areas of coal mine. This represents a significant volume of waste material. There would be considerable benefit to finding a use for this material. It is the intent of this project to look into the effect of pavement performance when bottom ashes from three power plant sources in Wyoming (Laramie River, Dave Johnston, and Jim Bridger) are added into asphalt mixes. The performance of these mixes was evaluated by conducting a laboratory evaluation and field evaluation. The laboratory evaluation consisted of preparing samples and then testing them for rutting, low temperature cracking and stripping. The field evaluation was done using experimental test sections in Gillette. Wyoming. These experimental test sections were tested with the Falling Weight Deflectometer (FWD). In addition the Pavement Condition Index (PCI) values were also determined for all of the sections. The statistical analyses showed that the field performance of all bottom ash mixes were comparable to the control mix, while the laboratory evaluation showed that all the ash mix performance exceeded control mix performance.

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