Effect of Hydrostatic Pressure on Grout Moisture and Solute Segregation

Authors

Rutambara Sonawane, Florida International UniversityFollow

Document Type

Dissertation

Degree

Doctor of Philosophy (PhD)

Major/Program

Civil Engineering

First Advisor's Name

Kingsley Lau

First Advisor's Committee Title

Co-committee chair

Second Advisor's Name

Berrin Tansel

Second Advisor's Committee Title

Co-committee chair

Third Advisor's Name

David Garber

Third Advisor's Committee Title

Committee member

Fourth Advisor's Name

Norman Munroe

Fourth Advisor's Committee Title

Committee member

Fifth Advisor's Name

Michael Sukop

Fifth Advisor's Committee Title

Committee member

Keywords

Post-tensioned, Bridges, Deficient Grout, Segregation, Hydrostatic Pressure, Diffusion, Sulfate, Corrosion, Steel Stand, Solute Transport

Date of Defense

11-7-2022

Abstract

Post-tensioned (PT) construction has been widely used in bridge construction due to its economic advantages and serviceability. However, recent findings showed severe corrosion is occurring in the steel strands of PT bridges. Investigations indicated localized corrosion at higher tendon elevations that is associated with deficient grout with high moisture and sulfate ion concentrations. Hardened grout inside the duct protects the steel strands from corrosion by creating a barrier between steel strands and external contaminants. However, corrosion due to the deficiencies in the grout material has been observed too. The objectives of this research were to identify: 1] if the hydrostatic pressure can transport water with solute at higher elevations, 2] if the diffusion and migration processes cause the transport of water and solute at higher elevations, and 3] the factor that is causing severe corrosion at higher elevations.

Schupack tests were performed to determine the effect of hydrostatic pressure on bleed water and solute transport. A vertical bleed test method was developed to identify the relationship between the elevation of the grout column and the deficiencies in the grout. Schupak test and vertical bleed test specimens were utilized to evaluate the performance of grout materials subjected to adverse construction practices including pre-hydration and addition of excess mix water. Results indicated that, at initial grout testing, sulfate ions are limited but would accumulate due to the transport of free water.

The Schupack test method showed that the hydrostatic pressure affects the bleed water and the sulfate concentration significantly. The vertical bleed test showed differences in the top bleed water, moisture content, sulfate concentration, porosity, and resistivity at different positions (Top, Middle, and Bottom) of grout columns. Sulfate diffusion and migration showed slight changes at different elevations. Simulation and statistical data analysis were needed to have a better understanding of the collected data. The diffusion in the grout column was simulated using Hydrus-1D. Similarly, multivariate regression analysis performed using SPSS concluded that the bleed water content increased with the increase in hydrostatic pressure, porosity, and that chloride migration in the grout column was affected, resulting into a deficient grout column.

Identifier

FIDC010877

ORCID

https://orcid.org/0000-0002-8598-1877

Recommended Citation

Sonawane, Rutambara, "Effect of Hydrostatic Pressure on Grout Moisture and Solute Segregation" (2022). FIU Electronic Theses and Dissertations. 5201.
https://digitalcommons.fiu.edu/etd/5201