Current Search: Reinforcing bars--Corrosion (x)
View All Items
(1 - 5 of 5)
- Title
- ESTIMATION OF THE PHYSICAL PROPERTIES OF CORRODING REBAR IN REINFORCED CONCRETE USING BIOT-STOLL MODEL INVERSION.
- Creator
- Brogden, Matthew, Beaujean, Pierre-Philippe, Florida Atlantic University, Department of Ocean and Mechanical Engineering, College of Engineering and Computer Science
- Abstract/Description
-
The detection of rebar corrosion in reinforced concrete is important due to the high costs of corrosion related damages to infrastructure. One such method of rebar corrosion lies in the use of non-destructive ultrasonic testing. To date, acoustic methods require either the training of an artificial neural network or a theory of acoustic wave propagation. Using a more complete acoustic model such as the Biot-Stoll model avoids algorithm training requirements by directly modeling the acoustic...
Show moreThe detection of rebar corrosion in reinforced concrete is important due to the high costs of corrosion related damages to infrastructure. One such method of rebar corrosion lies in the use of non-destructive ultrasonic testing. To date, acoustic methods require either the training of an artificial neural network or a theory of acoustic wave propagation. Using a more complete acoustic model such as the Biot-Stoll model avoids algorithm training requirements by directly modeling the acoustic environment. A problem with this method lies in the complexity of the model and the selection of free parameters. The problem of parameter selection is addressed by a series of targeted measurements using ultrasonic transducers on a set of existing reinforced concrete samples placed in a saltwater solution. This data can then be analyzed by a non-linear least squares solver to produce a better fit for the acoustic signal.
Show less - Date Issued
- 2022
- PURL
- http://purl.flvc.org/fau/fd/FA00014032
- Subject Headings
- Reinforcing bars--Corrosion, Reinforced concrete, Acoustics, Ultrasonics
- Format
- Document (PDF)
- Title
- Optimized Parameters Fitting of a Poro-Elastic Acoustic Model with Ultrasonic Measurements for the Monitoring of Corroding Rebar in Reinforced Concrete.
- Creator
- Shaffer, Samuel, Beaujean, Pierre-Philippe, Florida Atlantic University, Department of Ocean and Mechanical Engineering, College of Engineering and Computer Science
- Abstract/Description
-
Traditional techniques of observing cracking within reinforced structures can be invasive, leading to an increased risk of added corrosion to structures already undergoing corrosive processes. The research presented in this document improves upon a nondestructive method for detecting early crack formation in reinforced concrete. This method includes using acoustic signaling to add a layer of salt water between the sensor and analyzed sample. Following the collection of surface and rebar echo...
Show moreTraditional techniques of observing cracking within reinforced structures can be invasive, leading to an increased risk of added corrosion to structures already undergoing corrosive processes. The research presented in this document improves upon a nondestructive method for detecting early crack formation in reinforced concrete. This method includes using acoustic signaling to add a layer of salt water between the sensor and analyzed sample. Following the collection of surface and rebar echo responses, an adapted version of the novel Biot-Stoll method is used to model sound propagation for poro-elastic mediums. Testing of model parameters and variables has improved the root mean square error (RMSE) by up to 63.7% when studying the full signal, and up to 62.6% for the rebar echo locations. These improvements signify better curve fitting between simulated and measured responses, which lead to increased accuracy in the model parameter outputs.
Show less - Date Issued
- 2023
- PURL
- http://purl.flvc.org/fau/fd/FA00014265
- Subject Headings
- Reinforced concrete, Reinforcing bars--Corrosion, Ultrasonic testing
- Format
- Document (PDF)
- Title
- Evaluation of Corrosion Resistant Ferric-Alloys in Chloride Contaminated Concrete.
- Creator
- Himiob, Rodrigo J., Hartt, William H., Florida Atlantic University
- Abstract/Description
-
The penetration of chloride ions through concrete can compromise the integrity of a structure. The chloride concentration, [Cl-], at which the corrosion process initiates is termed the critical chloride concentration or chloride threshold, [Cl-]th. One of the purposes of this research was to determine the [Cl-]th for various reinforcing alloys. Furthermore, the time-to-corrosion (TIC) was measured to determine the time at which bars become active. Both parameters, [Cl-]th and TTC, were found...
Show moreThe penetration of chloride ions through concrete can compromise the integrity of a structure. The chloride concentration, [Cl-], at which the corrosion process initiates is termed the critical chloride concentration or chloride threshold, [Cl-]th. One of the purposes of this research was to determine the [Cl-]th for various reinforcing alloys. Furthermore, the time-to-corrosion (TIC) was measured to determine the time at which bars become active. Both parameters, [Cl-]th and TTC, were found to be distributed; therefore, statistical analyses were performed to forecast the probability of activity. A new experimental procedure was introduced to increase the TTC data set by electrically isolating the top bars as they became active. The research also compared the [Cl-] for core samples with those values obtained from along the top rebar trace. In general, this analysis demonstrated that core sample [Cr] was lower than at the rebar-trace.
Show less - Date Issued
- 2007
- PURL
- http://purl.flvc.org/fau/fd/FA00012527
- Subject Headings
- Steel--Corrosion, Reinforcing bars--Corrosion, Chlorides
- Format
- Document (PDF)
- Title
- Influence of chlorides and surface condition on pitting potential of high performance reinforcing steel.
- Creator
- Leroux, Virginie Edwige., Florida Atlantic University, Hartt, William H., College of Engineering and Computer Science, Department of Ocean and Mechanical Engineering
- Abstract/Description
-
In order to identify the influence of chlorides and surface finish on pitting potential of high performance reinforcing steel, cyclic polarization scans were performed on types 304, 2201 and 3Cr12 stainless steels and MMFX-II in simulated pore solution to which chloride was incrementally added. Furthermore, the surface condition was investigated with regard to the pitting potential. Pitting potential distributions versus the chloride content and surface finish were obtained. Pitting...
Show moreIn order to identify the influence of chlorides and surface finish on pitting potential of high performance reinforcing steel, cyclic polarization scans were performed on types 304, 2201 and 3Cr12 stainless steels and MMFX-II in simulated pore solution to which chloride was incrementally added. Furthermore, the surface condition was investigated with regard to the pitting potential. Pitting potential distributions versus the chloride content and surface finish were obtained. Pitting resistance was lowered as chloride was added and as the surface became rougher. Furthermore, a critical chloride to hydroxide ratio as a function of potential was determined for each material. Finally, according to the results of this study, the MMFX reinforcing steel was considered to have a corrosion performance close to that of Type 2201 stainless steel for bridge use. MMFX-II specimens with a polished surface exhibited more positive pitting potentials than did ones with an as-received finish.
Show less - Date Issued
- 2004
- PURL
- http://purl.flvc.org/fcla/dt/13103
- Subject Headings
- Reinforcing bars--Corrosion, Steel, Structural--Corrosion, Chlorides
- Format
- Document (PDF)
- Title
- Obstruction of chloride diffusion in concrete by embedded reinforcing bars.
- Creator
- Cros, Pascal., Florida Atlantic University, Hartt, William H.
- Abstract/Description
-
A study was performed of the effect of reinforcing bars on chloride diffusion into concrete. These bars act as obstacles to chloride movement, and this obstruction allows the chloride concentration to build-up faster along the top of the reinforcing bar than elsewhere. As a consequence, the critical chloride threshold to initiate corrosion of the steel is reached sooner than otherwise expected. This research was performed using two different methods. First, chloride analyses were performed on...
Show moreA study was performed of the effect of reinforcing bars on chloride diffusion into concrete. These bars act as obstacles to chloride movement, and this obstruction allows the chloride concentration to build-up faster along the top of the reinforcing bar than elsewhere. As a consequence, the critical chloride threshold to initiate corrosion of the steel is reached sooner than otherwise expected. This research was performed using two different methods. First, chloride analyses were performed on chloride exposed concrete blocks by taking cores in the concrete and drillings along the trace of the top bars. Second, concrete blocks models were analyzed by finite element analysis and the effect of the obstruction by the bar quantified. The role of the reinforcing bar in the chloride diffusional flow is discussed considering these two methods.
Show less - Date Issued
- 2005
- PURL
- http://purl.flvc.org/fcla/dt/13239
- Subject Headings
- Reinforcing bars--Corrosion, Reinforced concrete construction--Corrosion, Concrete--Additives, Chlorides--Diffusion rate
- Format
- Document (PDF)
