Details:

Creators:
Presuel-Moreno, Francisco J. ; Arias, Wendy ; Echevarria, Victor ; Shill, Scott ; Wu, Yu-You
Presuel-Moreno, Francisco J. ; Arias, Wendy ; Echevarria, Victor ; Shill, Scott ; Wu, Yu-You Less -
Corporate Creators:
Florida Atlantic University. Dept. of Ocean Engineering
Subject/TRT Terms:
[+]
Bridge Substructures Cement Chlorides Concentration (Chemistry) Durability Ions Reinforced Concrete Seawater Thermal Diffusion Underwater Structures
Publication/ Report Number:
BDK79-977-03
Resource Type:
Tech Report
Geographical Coverage:
Florida
Corporate Publisher:
Florida. Dept. of Transportation. Research Center
Abstract:
This investigation was performed to gain insight and assist in determining the long-term durability of

reinforced concrete structures where the external chloride concentrations are different than those typically

observed at the permanently immersed, tidal, and splash zones of partially immersed bridges. Insight into

the diffusion properties of the concrete at these locations may lead to changes in the state’s policy on

corrosion control of reinforced concrete structures. Structures at locations where the external chloride

concentrations may have spatial, let alone time, variation are of interest. Additionally, at elevations above

the splash zone, the amount of chlorides deposited would be lower, and the concrete close to the surface not

saturated. Similarly, the section of structures that extend inland would be subjected to seawater spray and

the concrete close to the surface would usually not be water saturated.

The performance in regard to chloride penetration of specimens made with three base compositions (the

supplementary cementitious materials were: 20% fly ash; 20% fly ash + 8% silica fume; and 50% slag),

and water-to-cementitious ratios of 0.35, 0.41, or 0.47 were investigated here. Experiments investigated

the diffusion of chloride ions into concrete samples that were exposed in scenarios that simulated the

splash, tidal, and immersed portions of a marine structure, with the solution ranging from brackish water to

10% seawater, to seawater. Bulk diffusion experiments were conducted in solutions that contained 0.6%,

3%, and 16.5% NaCl. Rapid migration tests and resistivity measurements were also performed several

times over two years, and the non-saturated migration coefficient vs. resistivity values were correlated. The

apparent diffusion values from the bulk diffusion tests were correlated to corresponding equivalent

resistivity values. Samples exposed for over 18 years, simulating tidal exposure were also part of this

investigation. The field component investigated the chloride concentration as a function of elevation. Other

experiments were conducted which involved controlling the degree of saturation and exposing a designated

surface to finely ground salt. These apparent diffusion results were compared to the apparent diffusion

results from specimens in which the chloride transport was due to natural marine atmosphere.


Format:
PDF
Collection(s):
US Transportation Collection
Main Document Checksum:
[+]
urn:sha256:f2d60dd5b03f017d955c825eb1ede6b833ef6ff142e548ae347d9c7b5396e48b
Download URL:
https://rosap.ntl.bts.gov/view/dot/27339/dot_27339_DS1.pdf
File Type:

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