Current Search: Corrosion and anti-corrosives. (x)
View All Items
- Title
- Atmospheric corrosion sensor studies in accelerated and natural environments.
- Creator
- Richard, Sebastien Laurent., Florida Atlantic University, Granata, Richard D., College of Engineering and Computer Science, Department of Ocean and Mechanical Engineering
- Abstract/Description
-
Tests in a cyclic chamber and in real atmospheric conditions resulted in the development of an improved corrosion coulometer sensor. First tests showed that it responded well in a reproduced environment but not satisfactorily in a real one, although it seemed to present a good correlation with the weather observations. However, these tests allowed a small time step data analysis of atmospheric corrosion and therefore an improved knowledge of this process. Also discussed are the possible ways...
Show moreTests in a cyclic chamber and in real atmospheric conditions resulted in the development of an improved corrosion coulometer sensor. First tests showed that it responded well in a reproduced environment but not satisfactorily in a real one, although it seemed to present a good correlation with the weather observations. However, these tests allowed a small time step data analysis of atmospheric corrosion and therefore an improved knowledge of this process. Also discussed are the possible ways of retrieving the corrosion coulometer data wirelessly, thus allowing a real-time analysis of atmospheric corrosion on steel structures. Ideas are proposed for improving both the sensor and the electronic package to make the system an efficient monitor of atmospheric corrosion.
Show less - Date Issued
- 2003
- PURL
- http://purl.flvc.org/fcla/dt/13041
- Subject Headings
- Corrosion and anti-corrosives, Voltameters, Detectors
- Format
- Document (PDF)
- Title
- Corrosion initiation on corrosion resistant alloys via acceleration chloride transport.
- Creator
- Gutierrez, Francisco, Graduate College
- Date Issued
- 2013-04-12
- PURL
- http://purl.flvc.org/fcla/dt/3361305
- Subject Headings
- Corrosion resistant alloys, Corrosion, Corrosion and anti-corrosives--Testing
- Format
- Document (PDF)
- Title
- Evaluation of carbon fiber/polyetheretherketone composites exposed to marine microbial communities in laboratory media and natural seawater.
- Creator
- Sheetz, Andrew Douglas., Florida Atlantic University, Hartt, William H., College of Engineering and Computer Science, Department of Ocean and Mechanical Engineering
- Abstract/Description
-
This research proposed to characterize any microbial induced degradation of carbon fiber/polyetheretherketone (PEEK) composites from acid-producing bacteria (APB) and sulfate-reducing bacteria (SRB). Electrochemical impedance spectroscopy (EIS) was used to provide a measure of degradation of the composite system as a function of exposure time. In addition, mechanical testing and microscopic evaluation of the specimens were utilized to determine if changes in the EIS spectra as a function of...
Show moreThis research proposed to characterize any microbial induced degradation of carbon fiber/polyetheretherketone (PEEK) composites from acid-producing bacteria (APB) and sulfate-reducing bacteria (SRB). Electrochemical impedance spectroscopy (EIS) was used to provide a measure of degradation of the composite system as a function of exposure time. In addition, mechanical testing and microscopic evaluation of the specimens were utilized to determine if changes in the EIS spectra as a function of exposure time correlated to changes in the mechanical properties. Results from most EIS scans were consistent with a well-consolidated and undamaged composite system. Changes in the EIS response of specimens exposed to the SRB environment were not matched by a reduction in the flexural strength. Mechanical testing also indicated no reduction in the flexural strength in any of the other exposure environments. Environmental scanning electron microscopy (ESEM)/energy dispersive x-ray spectroscopy (EDS) were inconclusive, though changes in the EDS spectra were seen. No definitive degradation was seen to occur in this composite system.
Show less - Date Issued
- 1998
- PURL
- http://purl.flvc.org/fcla/dt/15531
- Subject Headings
- Corrosion and anti-corrosives, Composite materials--Biodegradation
- Format
- Document (PDF)
- Title
- Effect of Polarization on Steel Embedded in Simulated Piling Specimens Evaluated by Critical Chloride Threshold.
- Creator
- Tanner, Russell, Hartt, William H., Florida Atlantic University, College of Engineering and Computer Science, Department of Ocean and Mechanical Engineering
- Abstract/Description
-
Critical chloride threshold, CT values for initiation of reinforced steel corrosion m mortar typical of Florida coastal bridge substructures were determined in laboratory tests. Previous research has reported CT values that vary by more than an order-of-magnitude, making design life estimation for structures difficult. On this basis, experiments on piling type specimens focused on [Cl-] contamination in the splash zone and coupling of this steel to a large surface area submerged anode. The...
Show moreCritical chloride threshold, CT values for initiation of reinforced steel corrosion m mortar typical of Florida coastal bridge substructures were determined in laboratory tests. Previous research has reported CT values that vary by more than an order-of-magnitude, making design life estimation for structures difficult. On this basis, experiments on piling type specimens focused on [Cl-] contamination in the splash zone and coupling of this steel to a large surface area submerged anode. The lower portion of simulated piling was immersed and the region above the waterline periodically sprayed with NaCI solution. Corrosion potential with respect to height above the waterline was monitored. A temporary depolarization method for determining as to whether or not corrosion had initiated is proposed. Chloride distribution at the reinforcement-concrete interface was determined in piling using energy dispersive x-ray analysis and related to height with respect to the waterline. Chloride threshold was related to corrosion potential.
Show less - Date Issued
- 2007
- PURL
- http://purl.flvc.org/fau/fd/FA00012560
- Subject Headings
- Reinforced concrete construction, Steel, Structural--Corrosion, Chlorides, Corrosion and anti-corrosives, Seawater corrosion
- Format
- Document (PDF)
- Title
- Influences of chlorides, pH and surface films on the corrosion of reinforcing steel in alkaline solutions.
- Creator
- Sundaresan, Raman., Florida Atlantic University, Hartt, William H., College of Engineering and Computer Science, Department of Ocean and Mechanical Engineering
- Abstract/Description
-
The objective of this study was to determine the influences of chlorides, pH and surface films on the corrosion of reinforcing steel in alkaline solutions. Anodic and linear polarization experiments were conducted on 1018 steel specimens exposed to these environments. The results indicate that there is a threshold amount of [Cl-] beyond which passivity is compromised. The i-passive in the electrolyte of pH 12.24 was approximately 0.01 of that in the electrolyte of pH 10.13. At least a one day...
Show moreThe objective of this study was to determine the influences of chlorides, pH and surface films on the corrosion of reinforcing steel in alkaline solutions. Anodic and linear polarization experiments were conducted on 1018 steel specimens exposed to these environments. The results indicate that there is a threshold amount of [Cl-] beyond which passivity is compromised. The i-passive in the electrolyte of pH 12.24 was approximately 0.01 of that in the electrolyte of pH 10.13. At least a one day period was necessary for the effect of the excess crystals of Ca(OH)2 to be felt. Corrosion rates of specimen with a Ca(OH)2 surface film were lower than without this film. [Cl-] /[OH-] in the range 2.5 to 3.5 appeared to be the threshold for breakdown of passivity.
Show less - Date Issued
- 1989
- PURL
- http://purl.flvc.org/fcla/dt/14520
- Subject Headings
- Reinforced concrete--Corrosion, Steel--Corrosion, Corrosion and anti-corrosives
- Format
- Document (PDF)
- Title
- Effect of steel reinforcement type and surface condition on corrosion initiation in mortar.
- Creator
- Huang, Yirong., Florida Atlantic University, Hartt, William H.
- Abstract/Description
-
This study employed half-cell potential (Eoc), polarization resistance (PR) and galvanic current tests to explore effects of surface condition and steel reinforcement type on corrosion initiation in mortar. A low impurity steel plate and #10 grade 60 rebar were used. Four surface conditions (as-received, atmospherically rusted, #240 SiC paper polished, and #500 SiC paper polished) were employed. Cyclic wet and dry exposure of specimens in 15% NaCl solution was conducted. Half-cell potential...
Show moreThis study employed half-cell potential (Eoc), polarization resistance (PR) and galvanic current tests to explore effects of surface condition and steel reinforcement type on corrosion initiation in mortar. A low impurity steel plate and #10 grade 60 rebar were used. Four surface conditions (as-received, atmospherically rusted, #240 SiC paper polished, and #500 SiC paper polished) were employed. Cyclic wet and dry exposure of specimens in 15% NaCl solution was conducted. Half-cell potential measurements showed that the corrosion probability of specimens with as-received and pre-rusted surfaces was lower than that of specimens with a polished surface. However, the PR and galvanic current tests indicated higher corrosion rate for specimens prepared with atmospherically rusted and as-received steels. Good agreement was found between results of the polarization resistance test and galvanic current measurements. There is a lack of correlation between half-cell potential and corrosion rate.
Show less - Date Issued
- 2003
- PURL
- http://purl.flvc.org/fcla/dt/13075
- Subject Headings
- Corrosion and anti-corrosives--Testing, Reinforced concrete--Corrosion, Mortar, Steel--Corrosion
- Format
- Document (PDF)
- Title
- Study of corrosion-induced failure mechanisms of epoxy-coated reinforcing steel.
- Creator
- Lee, Seung-Kyoung, Florida Atlantic University, Hartt, William H., McIntyre, Jack F., College of Engineering and Computer Science, Department of Ocean and Mechanical Engineering
- Abstract/Description
-
A study of the corrosion protection afforded by epoxy coatings on reinforcing steel was performed. To accomplish this bars were acquired from ten sources and coatings were characterized in terms of defects, thickness, solvent extraction weight loss and hardness. Testing involved exposure in various aqueous solutions at both ambient temperature and 80$\sp\circ$C and in chloride-contaminated concrete slabs under outdoor exposure. Direct pull-off adhesion testing was performed on tested and...
Show moreA study of the corrosion protection afforded by epoxy coatings on reinforcing steel was performed. To accomplish this bars were acquired from ten sources and coatings were characterized in terms of defects, thickness, solvent extraction weight loss and hardness. Testing involved exposure in various aqueous solutions at both ambient temperature and 80$\sp\circ$C and in chloride-contaminated concrete slabs under outdoor exposure. Direct pull-off adhesion testing was performed on tested and virgin epoxy coated reinforcing steels (ECRs). Electrochemical impedance spectroscopy (EIS) scans were made periodically, and a curve fitting technique was employed to analyze coating parameters. Conventional electrochemical measurements were also made, and corrosion morphology of ECR specimens was examined. It was found that the density and size of coating defects was the primary factor affecting ECR performance. The circuit analysis indicated that poorly performing defect-free coatings absorbed water and oxygen; and these species reached the coating/substrate interface and electrochemical reactions at the interface caused coating degradation. By way of contrast, the impedance response for well-performing ECR specimens showed no signs of active degradation at the interface although diffusional processes similar to those noted for poorly performing bars occurred here also. Experimental results indicated a relationship between corrosion behavior and bar source. Weight loss upon solvent extraction correlated with impedance reduction from hot water exposure. Coating defects developed during most of the tests, especially in high pH solutions containing chloride ions. ECRs with excessive coating defects, either initially present or ones which developed in service, performed poorly in every test category regardless of source. Forms of coating failure were extensive rusting at defects, blistering, wet adhesion loss, cathodic delamination, underfilm corrosion and coating cracks. These occurred sequentially or concurrently, depending on the condition of the ECR and nature of the environment.
Show less - Date Issued
- 1994
- PURL
- http://purl.flvc.org/fcla/dt/12389
- Subject Headings
- Corrosion and anti-corrosives, Epoxy coatings, Steel--Corrosion, Concrete--Corrosion
- Format
- Document (PDF)
- Title
- Design of cathodic protection using BEM for components of the piilot ocean energy system.
- Creator
- Gantiva, Nicolas., College of Engineering and Computer Science, Florida Atlantic University, Department of Ocean and Mechanical Engineering
- Abstract/Description
-
The Center for Ocean Energy Technology at Florida Atlantic University is developing an ocean energy turbine system to investigate the feasibility of harnessing Florida's Gulf Stream current kinetic energy and transforming it into a usable form. The turbine system has components which are prone to marine corrosion given the materials they are made of and to the harsh environment they will be exposed to. This study assumes a two-part system composed of a coating system acting as a barrier and...
Show moreThe Center for Ocean Energy Technology at Florida Atlantic University is developing an ocean energy turbine system to investigate the feasibility of harnessing Florida's Gulf Stream current kinetic energy and transforming it into a usable form. The turbine system has components which are prone to marine corrosion given the materials they are made of and to the harsh environment they will be exposed to. This study assumes a two-part system composed of a coating system acting as a barrier and sacrificial anode cathodic protection which polarizes the metal structures to a potential value where corrosion is significantly reduced. Several configurations (varying in anode quantity, size and location) were considered in order to cathodically protect the structures with various coating qualities (poor, good and excellent). These cases were modeled and simulated via Boundary Element Method software and analyzed so as to assess the most appropriate design.
Show less - Date Issued
- 2010
- PURL
- http://purl.flvc.org/FAU/2684309
- Subject Headings
- Cathodic protection, Corrosion and anti-corrosives, Finite element method, Seawater corrosion, Prevention
- Format
- Document (PDF)
- Title
- Cathodic polarization response of simulated prestressed concrete piles exposed to natural sea water.
- Creator
- Chaix, Olivier., Florida Atlantic University, Hartt, William H.
- Abstract/Description
-
Experiments were conducted to determine the effectiveness of localized cathodic polarization for reducing corrosion of simulated prestressed concrete piles containing admixed calcium chloride and exposed to a simulated sea water tidal cycle. The specimens contained both continuous and segmented steel tendons, the purpose of the latter being to facilitate measurement of cathodic protection current. Conductive rubber in an impressed current system was used as the anode material. The specimens...
Show moreExperiments were conducted to determine the effectiveness of localized cathodic polarization for reducing corrosion of simulated prestressed concrete piles containing admixed calcium chloride and exposed to a simulated sea water tidal cycle. The specimens contained both continuous and segmented steel tendons, the purpose of the latter being to facilitate measurement of cathodic protection current. Conductive rubber in an impressed current system was used as the anode material. The specimens were initially freely corroded and then cathodically polarized at a constant current ranging from 0.5 to 1 mA/m$\sp2$ which corresponded to potentials (current-on) which ranged from $-$0.500 to $-$1.100 V(sce) in the anode region. The magnitude of impressed current and its distribution along the embedded steel was monitored as a function of exposure time, level of polarization and water levels. Current-on and instant-off potential distribution for both the continuous and segmented tendons were also measured. The level of cathodic polarization was assessed as a function of position along the specimens by the depolarization method. The results were evaluated within the context of marine bridge substructure cathodic protection technology.
Show less - Date Issued
- 1992
- PURL
- http://purl.flvc.org/fcla/dt/14865
- Subject Headings
- Corrosion and anti-corrosives, Sea-water corrosion, Offshore structures, Reinforced concrete--Deterioration
- Format
- Document (PDF)
- Title
- Effect of cathodic protection and cyclic frequency on corrosion fatigue of selected high strength steels in seawater.
- Creator
- Badve, Ashwin P., Florida Atlantic University, Hartt, William H.
- Abstract/Description
-
Study of selected candidate steels for offshore application was undertaken to observe the effects of cathodic protection and cyclic frequency on corrosion fatigue life. Keyhole Compact Tension Fatigue experiments under constant amplitude sinusoidal loading and stress ratio of 0.5 were performed on 25.4 mm thick specimens in natural sea water and also in air upon three different steels (Y.S. 500-563 MPa). These steels represented different strengthening techniques, namely precipitation...
Show moreStudy of selected candidate steels for offshore application was undertaken to observe the effects of cathodic protection and cyclic frequency on corrosion fatigue life. Keyhole Compact Tension Fatigue experiments under constant amplitude sinusoidal loading and stress ratio of 0.5 were performed on 25.4 mm thick specimens in natural sea water and also in air upon three different steels (Y.S. 500-563 MPa). These steels represented different strengthening techniques, namely precipitation hardening, direct quenching--a thermomechanical control process (TMCP), and controlled rolling. Cathodic polarization was in the range between freely corroding and -1.10 Volts (SCE). The tests were performed at a frequency of 0.3 and 1.0 Hz. The results are presented in the S-N and potential versus cycles to initiation format. No effect of frequency (1.0-0.3 Hz) was observed at cathodic protection of -1.10 V (SCE). The steels showed an increase in fatigue life to an optimum potential, and excessive potentials were detrimental. The fatigue life in dry air was greater than in laboratory air (~50% RH).
Show less - Date Issued
- 1989
- PURL
- http://purl.flvc.org/fcla/dt/14494
- Subject Headings
- Marine steel--Fatigue, Offshore structures, Sea-water corrosion, Corrosion and anti-corrosives
- Format
- Document (PDF)
- Title
- Evaluation of corrosion behavior of ion vapor deposited aluminum related coating systems.
- Creator
- Hang, Ling., Florida Atlantic University, McIntyre, Jack F.
- Abstract/Description
-
Experiments were conducted to investigate the effectiveness of ion vapor deposited (IVD) aluminum as a base coat for polyurethane topcoat systems in marine environments. Three test environments were used including marine atmospheric atmosphere, quiescent filtered seawater open to laboratory air and aerated seawater. Visual observation and electrochemical impedance spectroscopy techniques were primary testing methods; other characterizations included adhesion tape test, coating thickness...
Show moreExperiments were conducted to investigate the effectiveness of ion vapor deposited (IVD) aluminum as a base coat for polyurethane topcoat systems in marine environments. Three test environments were used including marine atmospheric atmosphere, quiescent filtered seawater open to laboratory air and aerated seawater. Visual observation and electrochemical impedance spectroscopy techniques were primary testing methods; other characterizations included adhesion tape test, coating thickness measurements, holiday detection, optical microscopy, open circuit potential measurements and potentiodynamic polarization. It was found that IVD aluminum was a good candidate for replacement of environmentally sensitive coatings on AA2219-T87 and AISI 4340 steel substrates, respectively. The IVD aluminum coating provided good sacrificial protection and served as a good base for polyurethane topcoat systems. Electrochemical impedance spectroscopy was a suitable method to predict coating performance in the early stages of exposure.
Show less - Date Issued
- 1993
- PURL
- http://purl.flvc.org/fcla/dt/14970
- Subject Headings
- Aluminum coating, Corrosion and anti-corrosives, Metals--Corrosion fatigue, Electrochemical analysis
- Format
- Document (PDF)
- Title
- Mathematical modeling of the pit initiation process.
- Creator
- Kappukattil, Lizamma Joseph., Florida Atlantic University, Lee, Rupert U., College of Engineering and Computer Science, Department of Ocean and Mechanical Engineering
- Abstract/Description
-
The potential at which pitting corrosion begins under anodic polarization is a function of the environmental parameters. Determination of this characteristic potential enables prediction of pitting susceptibility under specific environmental conditions. The pitting potentials were determined experimentally for AISI 304 stainless steel for different values of chloride ion concentration, sulphate ion concentration, temperature and solution pH. A factorial design technique was employed to study...
Show moreThe potential at which pitting corrosion begins under anodic polarization is a function of the environmental parameters. Determination of this characteristic potential enables prediction of pitting susceptibility under specific environmental conditions. The pitting potentials were determined experimentally for AISI 304 stainless steel for different values of chloride ion concentration, sulphate ion concentration, temperature and solution pH. A factorial design technique was employed to study the individual and interaction effects of parameters in order to investigate the multi-faceted nature of the pitting process. An empirical model was developed based on the result of the factorial analysis. The model emphasizes the fact that the pit nucleation process involves interrelated processes, and that the parameters behave differently with respect to each process.
Show less - Date Issued
- 1989
- PURL
- http://purl.flvc.org/fcla/dt/14548
- Subject Headings
- Corrosion and anti-corrosives--Mathematical models, Metals--Corrosion fatigue--Mathematical models
- Format
- Document (PDF)
- Title
- Experimental and theoretical characterization of near-threshold fatigue crack growth for high strength steels in seawater.
- Creator
- Yang, Jingjun., Florida Atlantic University, Hartt, William H., College of Engineering and Computer Science, Department of Ocean and Mechanical Engineering
- Abstract/Description
-
Near-threshold fatigue crack growth rate data were generated for six high strength steels at stress ratios of 0.5 and 0.8 under different environmental conditions, which included air, freely corroding in seawater, and cathodically polarized in seawater to -0.80v, -0.95v and -1.10v (vs SCE). The influence of stress ratio, loading frequency, magnitude of cathodic polarization and initial DeltaK on fatigue crack growth behavior for these high strength steels was experimentally characterized. The...
Show moreNear-threshold fatigue crack growth rate data were generated for six high strength steels at stress ratios of 0.5 and 0.8 under different environmental conditions, which included air, freely corroding in seawater, and cathodically polarized in seawater to -0.80v, -0.95v and -1.10v (vs SCE). The influence of stress ratio, loading frequency, magnitude of cathodic polarization and initial DeltaK on fatigue crack growth behavior for these high strength steels was experimentally characterized. The results disclosed general trends of fatigue crack growth under conditions relevant to offshore structure applications and circumscribed variables that are primarily influential with regard to service performance. The rate controlling processes and cracking mechanisms of near-threshold fatigue crack growth, particularly under cathodic polarization in seawater, were also studied in conjunction with crack mouth opening displacement measurements, fractographic observation and crack profile examination. The data and observations suggest that calcareous deposit induced closure was the rate-controlling factor for near-threshold fatigue crack growth under cathodic polarization in seawater although the cracking involved a brittle failure mechanism as a result of hydrogen embrittlement. With different FCGR determining procedures which included natural K-decreasing, enhanced K-decreasing, natural K-increasing and constant DeltaK, the FCGR under cathodic polarization in seawater was found to be time-dependent and, as such, was not a unique function of DeltaK but depended upon K-history or experimental procedures. These observations were consistent with results of a theoretical analysis which involved kinetics modeling of the interaction between fatigue crack growth and calcareous deposit thickening. The model also predicted the existence of an upper limit transition DeltaK, DeltaK Upp/T, between the Paris and threshold regions and it was found that the predicted DeltaK Upp/T was in agreement with the experimental one. The basis for applying this critical parameter (DeltaK Upp/T) to offshore structure designs was addressed in conjunction with experimental results.
Show less - Date Issued
- 1995
- PURL
- http://purl.flvc.org/fcla/dt/12410
- Subject Headings
- Seawater corrosion, Steel--Fatigue, Steel--Fracture, Corrosion and anti-corrosives
- Format
- Document (PDF)
- Title
- Accelerated corrosion of steel in dry-cast reinforced concrete pipes after initiation.
- Creator
- Weber, Brian W., Presuel-Moreno, Francisco, Florida Atlantic University, College of Engineering and Computer Science, Department of Ocean and Mechanical Engineering
- Abstract/Description
-
Instrumented dry-cast reinforced concrete pipe (DC-RCP) specimens in which corrosion of the reinforcing steel had initiated were selected to accelerate the corrosion. Type C and type F DC-RCP were used. An anodic current density of various magnitudes (0.5 μA/cm2, 1 μA/cm2 and 2.5 μA/cm2) was applied during the corrosion propagation stage. The specimens were placed in high humidity and selected specimens were later covered with wet sand. Selected specimens were terminated for visual...
Show moreInstrumented dry-cast reinforced concrete pipe (DC-RCP) specimens in which corrosion of the reinforcing steel had initiated were selected to accelerate the corrosion. Type C and type F DC-RCP were used. An anodic current density of various magnitudes (0.5 μA/cm2, 1 μA/cm2 and 2.5 μA/cm2) was applied during the corrosion propagation stage. The specimens were placed in high humidity and selected specimens were later covered with wet sand. Selected specimens were terminated for visual examination and gravimetric analysis. Typically, the reinforcement potentials during the accelerated corrosion period were more negative for F specimens compared to C specimens. The C specimens experienced ~2× more corrosion than the F specimens. The accumulated corrosion products did not cause cracks. A method was developed that allows for modest corrosion acceleration during the corrosion propagation stage of DC-RCP.
Show less - Date Issued
- 2014
- PURL
- http://purl.flvc.org/fau/fd/FA00004233, http://purl.flvc.org/fau/fd/FA00004233
- Subject Headings
- Concrete -- Deterioration, Corrosion and anti corrosives, Pipelines -- Design and construction, Tubular steel structures -- Deterioration
- Format
- Document (PDF)
- Title
- Pitting potential of high performance duplex stainless steels reinforcements.
- Creator
- Sanchez, Erika Maria., College of Engineering and Computer Science, Department of Ocean and Mechanical Engineering
- Abstract/Description
-
A cyclic polarization procedure was designed to evaluate the pitting potentials of high performance stainless steels in synthetic concrete pore water at different chloride concentrations. Cyclic polarization scans were performed on high performance stainless steel reinforcements, S32201, S32305 and S32205. Pitting initiation was observed below the oxygen evolution potential for high chloride concentrations. S32201 and S32304 showed the presence of metastable pitting before reaching its...
Show moreA cyclic polarization procedure was designed to evaluate the pitting potentials of high performance stainless steels in synthetic concrete pore water at different chloride concentrations. Cyclic polarization scans were performed on high performance stainless steel reinforcements, S32201, S32305 and S32205. Pitting initiation was observed below the oxygen evolution potential for high chloride concentrations. S32201 and S32304 showed the presence of metastable pitting before reaching its pitting potential. Pitting resistance performance, based on cyclic polarization, was consistent with each material's respective Pitting Resistance Equivalent Number (PREN) value. For S32201 and S32304, pitting potential decreased as the chloride concentration increased, whereas S32205 did not pit at the chloride concentrations tested.
Show less - Date Issued
- 2011
- PURL
- http://purl.flvc.org/FAU/3334100
- Subject Headings
- Reinforced concrete construction, Steel, Structural, Testing, Corrosion and anti-corrosives
- Format
- Document (PDF)
- Title
- Initiation and propagation of corrosion in dry-cast reinforced concrete ring specimens.
- Creator
- Seo, Bongjoon, Presuel-Moreno, Francisco, Florida Atlantic University, College of Engineering and Computer Science, Department of Ocean and Mechanical Engineering
- Abstract/Description
-
The corrosion propagation stage of D-CRP (types F and C) was tested under immersion in water, high humidity, and covered with wet sand. The half-cell potential, linear polarization test, and electrochemical impedance spectroscopy measurements were performed. Selected specimens were terminated after 300 days of exposure and visually inspected. Based on corrosion potential measurements obtained during the corrosion propagation observation, and calculated corrosion rate based on LPR measurements...
Show moreThe corrosion propagation stage of D-CRP (types F and C) was tested under immersion in water, high humidity, and covered with wet sand. The half-cell potential, linear polarization test, and electrochemical impedance spectroscopy measurements were performed. Selected specimens were terminated after 300 days of exposure and visually inspected. Based on corrosion potential measurements obtained during the corrosion propagation observation, and calculated corrosion rate based on LPR measurements: all specimens were actively corroding. Additionally, EIS-Rc values were calculated for FS, CS and CH specimens. The Rc_EIS were generally greater than Rc_LPR values. EIS spectra for CI and FI specimens usually included mass transport limitations, as these specimens were immersed. Both type of specimens immersed in water (FI and CI), appeared to have higher corrosion rate based on LPR-Rc. However, upon autopsy it was revealed that a more modest amount of corrosion occurred on the reinforcing steel of FI and CI terminated specimens.
Show less - Date Issued
- 2014
- PURL
- http://purl.flvc.org/fau/fd/FA00004226, http://purl.flvc.org/fau/fd/FA00004226
- Subject Headings
- Concrete -- Deterioration, Concrete construction, Corrosion and anti corrosives, Reinforced concrete -- Chemical resistance, Tubular steel structures -- Deterioration
- Format
- Document (PDF)
- Title
- Modeling of bracelet anodes and anode arrays for pipeline CP systems.
- Creator
- Zhang, Xiaolin., Florida Atlantic University, Hartt, William H., College of Engineering and Computer Science, Department of Ocean and Mechanical Engineering
- Abstract/Description
-
Two models for pipeline bracelet anodes depletion with time were analyzed: one with uniform corrosion and the other with localized corrosion. The potential of the pipeline was determined to become more positive with time due to corrosion of the anode. The pipeline protected by the anode with localized corrosion had more a positive potential than the one protected by the anode with uniform corrosion. A method based upon the equations of Sunde was developed for determining resistance of linear...
Show moreTwo models for pipeline bracelet anodes depletion with time were analyzed: one with uniform corrosion and the other with localized corrosion. The potential of the pipeline was determined to become more positive with time due to corrosion of the anode. The pipeline protected by the anode with localized corrosion had more a positive potential than the one protected by the anode with uniform corrosion. A method based upon the equations of Sunde was developed for determining resistance of linear and rectangular anode arrays. Accuracy of this approach was evaluated using Boundary Element Modeling (BEM). The difference between the two methods was defined as Error. A corrected function of Sunde's equation was developed in order to get a more accurate resistance of a 1 x N anode array. The influence on resistance of a M x N (M < N) anode array of anode size, separation distance and array number was analyzed. Error increased with increasing anode size and decreased with increasing number of anodes and separation distance. The application and limitations of commonly used anode resistance formulas are discussed.
Show less - Date Issued
- 2003
- PURL
- http://purl.flvc.org/fcla/dt/13087
- Subject Headings
- Pipelines--Cathodic protection, Corrosion and anti-corrosives, Underwater pipelines, Anodes
- Format
- Document (PDF)
- Title
- Initiation and propagation of corrosion in dry-cast reinforced concrete pipes.
- Creator
- Balasubramanian, Hariharan, College of Engineering and Computer Science, Department of Ocean and Mechanical Engineering
- Abstract/Description
-
This study investigates corrosion initiation and propagation in instrumented specimens obtained from segments of dry-cast reinforced concrete pipes. Potential, LPR and EIS measurements were carried out. During the propagation stage in different exposures, reinforcement eventually reached negative potentials values, which suggest mass transfer limitations. So far these specimens show no visual signs of corrosion such as cracks or corrosion products with one exception; where corrosion products...
Show moreThis study investigates corrosion initiation and propagation in instrumented specimens obtained from segments of dry-cast reinforced concrete pipes. Potential, LPR and EIS measurements were carried out. During the propagation stage in different exposures, reinforcement eventually reached negative potentials values, which suggest mass transfer limitations. So far these specimens show no visual signs of corrosion such as cracks or corrosion products with one exception; where corrosion products have reached the surface. Moreover, the apparent corrosion rate values obtained suggest high corrosion rate. No crack appearance so far, could be explained by the high porosity of the specimens; the corrosion products are filling these pores. It is speculated that although, there might be mass transfer limitations present, the current demanded by the anode is being balanced by a larger cathode area due to macrocell effects, since the high moisture conditions likely reduced the concrete resistivity and increased the throwing power.
Show less - Date Issued
- 2013
- PURL
- http://purl.flvc.org/fcla/dt/3362341
- Subject Headings
- Concrete, Deterioration, Tubular steel structures, Deterioration, Pipelines, Design and construction, Concrete construction, Corrosion and anti-corrosives
- Format
- Document (PDF)
- Title
- Evaluation of Chloride Threshold for Steel Fiber Reinforced Concrete Composited in Aggressively Corrosive Environments.
- Creator
- Vogel, Dietrich H., Presuel-Moreno, Francisco, Florida Atlantic University, College of Engineering and Computer Science, Department of Ocean and Mechanical Engineering
- Abstract/Description
-
Highway drainage pipes utilize concrete reinforced with steel wire to help mitigate water, earth, and traffic loads. Drainage pipes reinforced with zinc electroplated steel fibers offer a lower steel alternative to traditional steel wire cage reinforcements. The objective of the thesis research was to determine the physical and electrochemical characteristics of zinc electroplated steel fiber corrosion propagation. Experimental programs include: Fracture analysis of zinc electroplated steel...
Show moreHighway drainage pipes utilize concrete reinforced with steel wire to help mitigate water, earth, and traffic loads. Drainage pipes reinforced with zinc electroplated steel fibers offer a lower steel alternative to traditional steel wire cage reinforcements. The objective of the thesis research was to determine the physical and electrochemical characteristics of zinc electroplated steel fiber corrosion propagation. Experimental programs include: Fracture analysis of zinc electroplated steel fibers embedded in dry-cast concrete pipes exposed to varying chloride concentrations; Visual analysis of zinc electroplated steel fibers embedded in concrete exposed to varying chloride concentrations; Electrochemical analysis of zinc electroplated steel fibers embedded in concrete exposed to varying chlorides; Chloride threshold determination for zinc electroplated steel fibers immersed in simulated pore solution. Between the four experimental programs the most significant conclusion is that oxygen, moisture, and chlorides past the chloride threshold must be present for corrosion to propagate significantly on the zinc electroplated steel fibers.
Show less - Date Issued
- 2016
- PURL
- http://purl.flvc.org/fau/fd/FA00004637, http://purl.flvc.org/fau/fd/FA00004637
- Subject Headings
- Fiber-reinforced concrete--Cracking., Cement composites., Reinforced concrete construction., Reinforced concrete--Corrosion., Corrosion and anti-corrosives., Structural engineering.
- Format
- Document (PDF)