Graduation Year
2019
Document Type
Dissertation
Degree
Ph.D.
Degree Name
Doctor of Philosophy (Ph.D.)
Degree Granting Department
Civil and Environmental Engineering
Major Professor
A. Gray Mullins, Ph.D.
Co-Major Professor
Alberto Sagüés, Ph.D.
Committee Member
Abla Zayed, Ph.D.
Committee Member
Richard Gilbert, Ph.D.
Committee Member
Travis Doering, Ph.D.
Keywords
Axial Strength, Bentonite, Foundations, Polymer
Abstract
Until recently, concrete flow in tremie-placed drilled shafts has been mischaracterized as rising uniformly with laitance formation occurring only at the top of the rising concrete in the shaft. In actuality, concrete first fills a portion of the reinforcement cage to a sufficient height to promote radial flow into the cover region. Depending on support fluid type, the radial flow can produce laitance-filled creases/channels projecting the reinforcing cage configuration to the side of shaft surface. The flow pattern (and creases) can affect filter cake thickness, cover quality and propensity for corrosion. This research examines 52 tremie-placed laboratory drilled shaft specimens constructed using bentonite, polymer or natural support fluid to identify correlations between support fluid type and laitance channel formation. The extent of the laitance channel effect was quantified with surface texture, corrosion potential, and strength distribution methods. A direct correlation between the use of bentonite support fluid and laitance channel formation was identified which showed a high propensity for corrosion and lower concrete strengths.
Scholar Commons Citation
Mobley, Sarah J., "Effects of Support Fluid Type on Concrete Integrity and Durability in Drilled Shafts" (2019). USF Tampa Graduate Theses and Dissertations.
https://digitalcommons.usf.edu/etd/7859
