Degree Type

Thesis

Date of Award

2007

Degree Name

Master of Science

Department

Geological and Atmospheric Sciences

Major

Environmental Science

First Advisor

Robert Horton

Second Advisor

Neal Iverson

Third Advisor

David J. White

Abstract

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.

DOI

https://doi.org/10.31274/rtd-180813-7420

Publisher

Digital Repository @ Iowa State University, http://lib.dr.iastate.edu/

Copyright Owner

Heath Gieselman

Language

en

Proquest ID

1443135

OCLC Number

173298970

File Format

application/pdf

File Size

34 pages

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