Date of Award
Master of Science
Geological and Atmospheric Sciences
David J. White
Frost heave is the process in which wet soil with an available water source undergoes freezing, deformation, and upward movement of the soil surface. This deformation can cause damage to engineering structures such as pavements and shallow foundations. Investigating ways to minimize frost heave by reducing water flow in the system is beneficial. A possible way to reduce the water movement is to add a hydrophobic layer of soil between the water source (e.g. water table) and the freezing surface. The objective of this study was to examine the effect of a hydrophobic treated soil layer on water movement and temperature changes in a soil profile under surface freezing conditions. A vertical soil cell set-up including a column-within-a-column design was used to establish one-dimensional vertical heat flow between a surface boundary condition below freezing and an ambient boundary temperature condition at the bottom of the cell. A constant water table was established at the bottom of the column to provide a water source for water uptake due to freezing. Water uptake in soil cells without a hydrophobic layer was found to be greater by one order of magnitude than water uptake in soil cells with a hydrophobic layer. Soil with a hydrophobic layer had less accumulation of ice and froze to greater depths than soil without a hydrophobic layer. A hydrophobic soil layer can reduce water movement in freezing soil.
Digital Repository @ Iowa State University, http://lib.dr.iastate.edu/
Gieselman, Heath, "Effect of a hydrophobic layer on the upward movement of water under freezing conditions" (2007). Retrospective Theses and Dissertations. 13952.