Amy Decker

Date of Award


Document Type

Senior Project

Degree Name

Bachelor of Science (BS)


Geological Engineering

First Advisor

Dr. Scott F. Korom


Combustion of coal occurs worldwide to produce energy for numerous residential and industrial processes. During coal combustion, byproducts including fly ash, bottom ash and slag are formed (Lafarge, 2004). By standard regulations, power plants in the United States and many other countries must effectively capture and dispose of these byproducts. Over 118 million tons of combustion byproducts are produced and captured each year in the United States alone. Disposal of this extraordinary amount of waste is difficult and costly. Finding ways to turn this waste into a resource has been necessary, and at times, profitable.

The past fifty years has witnessed great advancement in the understanding of coal byproducts and their potential for use in a variety of settings. One common application incorporates fly ash into the construction of road surfaces. Fly ash can be used in combination with, or in place of, other aggregates to strengthen road-base soils (Parsons and Kneebone, 2004). The proportional amount of fly ash that should be used in such an application depends on many factors including, but not limited to, climate, soil properties, groundwater conditions, and construction strength requirements.

Based on a pilot study completed as a senior design project, the objective of this report is to design a testing methodology and schedule to determine optimal parameters for fly ash addition to strengthen road-base soils in the Northern Red River Valley. The project has been designed with the assistance of Lafarge, International. The expected outcome will be a procedure and set of testing results that can be used by others to determine optimum fly ash proportions for specific soil types. Also included are the results of the pilot study for one typical soil collected from Casselton, North Dakota. The development of the procedure is expected to provide the basis of a thesis for a graduate student pursuing a Master's of Science degree in Geological Engineering.