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Title: Adhesion of calcareous deposits formed on steel surfaces under cathodic polarization.
Creator: Luo, Jiunn-Shyong, Florida Atlantic University, Hartt, William H., College of Engineering and Computer Science, Department of Ocean and Mechanical Engineering
Abstract/Description: A procedure has been devised to characterize the adhesion of calcareous deposits formed upon steel in association with cathodic polarization in seawater. This involved bending the substrate in-situ and characterization of deposit debonding in terms of visual appearance, changes in the cathodic current density and the net charge transferred in association with film disruption. Specific attention has been focused upon the influence of exposure time, applied potential, flow rate, temperature,...
Show moreA procedure has been devised to characterize the adhesion of calcareous deposits formed upon steel in association with cathodic polarization in seawater. This involved bending the substrate in-situ and characterization of deposit debonding in terms of visual appearance, changes in the cathodic current density and the net charge transferred in association with film disruption. Specific attention has been focused upon the influence of exposure time, applied potential, flow rate, temperature, substrate surface finish and electrolyte type upon deposit adhesion. Presence of a Mg-rich, inner film as well as the impingement of CaCO3 particles enhanced the adhesion of calcareous deposits. Electrostatic forces, Van der Waals attraction, and chemical alteration of precipitates could be important factors contributing to deposit adhesion.
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Date Issued: 1991
PURL: http://purl.flvc.org/fcla/dt/12271
Subject Headings: Sea-water corrosion, Marine steel, Cathodic protection, Adhesives
Format: Document (PDF)

Title: Brittle propensity of chromium microalloyed and corroded prestressing steel under cathodic protection.
Creator: Stauder, Anne-Laure T., Florida Atlantic University, Hartt, William H., College of Engineering and Computer Science, Department of Ocean and Mechanical Engineering
Abstract/Description: Qualification criteria for cathodic protection of pre-tensioned tendon wires in concrete were studied with regard to the risks of embrittlement due to chromium microalloying and existing corrosion damage. The selected materials included two microalloyed (with 0.23 and 0.24 w% chromium) and one non-microalloyed, high carbon prestressing steels. The slow strain rate testing technique was used to evaluate the effects of polarization to -0.90 and -1.30 VSCE upon strength and ductility of the...
Show moreQualification criteria for cathodic protection of pre-tensioned tendon wires in concrete were studied with regard to the risks of embrittlement due to chromium microalloying and existing corrosion damage. The selected materials included two microalloyed (with 0.23 and 0.24 w% chromium) and one non-microalloyed, high carbon prestressing steels. The slow strain rate testing technique was used to evaluate the effects of polarization to -0.90 and -1.30 VSCE upon strength and ductility of the steels. Fractographic analysis was performed using scanning electron microscopy. Based upon statistical analysis, an attempt was made to relate the remaining strength of the corroded wire to the extent of corrosion damage for different corrosion morphologies.
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Date Issued: 1997
PURL: http://purl.flvc.org/fcla/dt/15475
Subject Headings: Cathodic protection, Tendons (Prestressed concrete), Steel--Corrosion, Steel--Embrittlement
Format: Document (PDF)

Title: Characterization of electrochemical properties of arc-sprayed zinc and zinc-aluminum alloy coatings for cathodic protection of reinforced concrete structures.
Creator: Sigonney, Yann Manuel., Florida Atlantic University, Hartt, William H., College of Engineering and Computer Science, Department of Ocean and Mechanical Engineering
Abstract/Description: The present research focused on the behavior of arc sprayed zinc and zinc-aluminum coatings on concrete specimens exposed to specific relative humidity environments (100, 85, 60 and 25% RH) and with specific chloride contents (0.0, 3.0, 5.9 and 11.8 kg/m^3). All specimens experienced a decline in current output with time. Anode wastage and formation of oxidation products were mainly responsible for this lack of protection in 100 and 85% RH, whereas for 60 and 25% RH, drying of the concrete...
Show moreThe present research focused on the behavior of arc sprayed zinc and zinc-aluminum coatings on concrete specimens exposed to specific relative humidity environments (100, 85, 60 and 25% RH) and with specific chloride contents (0.0, 3.0, 5.9 and 11.8 kg/m^3). All specimens experienced a decline in current output with time. Anode wastage and formation of oxidation products were mainly responsible for this lack of protection in 100 and 85% RH, whereas for 60 and 25% RH, drying of the concrete and long-term polarization of the anode were the key factors. Validity of the DC measurements was verified with slope parameter analysis on selected specimens. In addition, Electrochemical Impedance Spectroscopy was performed on the galvanic anode and an equivalent circuit model was obtained for the zinc-concrete interface.
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Date Issued: 1999
PURL: http://purl.flvc.org/fcla/dt/15665
Subject Headings: Reinforced concrete--Corrosion, Cathodic protection, Zinc coating
Format: Document (PDF)

Title: A critical evaluation of current demand determination methods for cathodic protection retrofits of offshore structures.
Creator: Lemieux, Edward John., Florida Atlantic University, Hartt, William H., College of Engineering and Computer Science, Department of Ocean and Mechanical Engineering
Abstract/Description: Development of a baseline design protocol for cathodic protection retrofits of offshore structures is becoming an increasingly important topic in light of the large number of structures operating beyond their original cp system design life. One of the critical steps in this development is determination of the total anode mass which is required to continue sufficient cathodic protection for which structure current demand must be established. Three current demand determination methods were...
Show moreDevelopment of a baseline design protocol for cathodic protection retrofits of offshore structures is becoming an increasingly important topic in light of the large number of structures operating beyond their original cp system design life. One of the critical steps in this development is determination of the total anode mass which is required to continue sufficient cathodic protection for which structure current demand must be established. Three current demand determination methods were investigated including the Gaussian ammeter, the Potential method, which utilizes the driving potential and anode resistance in its current calculation, and the IR Drop method. To this end, three anodes were deployed at the Naval Research Laboratory, Key West, Fl., and current output determinations were made upon these. Each of the three current measurement methods was evaluated on the basis of accuracy, reliability and feasibility in field use.
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Date Issued: 1997
PURL: http://purl.flvc.org/fcla/dt/15503
Subject Headings: Cathodic protection, Offshore structures, Ocean currents
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.
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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: Embrittlement susceptibility of corroded pre-stressing steel in concrete during cathodic polarization.
Creator: Poeydomenge, Arnaud., Florida Atlantic University, Hartt, William H., College of Engineering and Computer Science, Department of Ocean and Mechanical Engineering
Abstract/Description: Experiments and analyses were performed to better define the limits of concern regarding hydrogen embrittlement in association with application of cathodic protection to prestressed concrete. To accomplish this, prestressed concrete specimens were locally corroded to different levels by anodic polarization and then polarized to -1.30 V SCE. A procedure of examination was developed using strain gauges to determine the level of prestrain. Relatively few brittle failures of wires resulted due,...
Show moreExperiments and analyses were performed to better define the limits of concern regarding hydrogen embrittlement in association with application of cathodic protection to prestressed concrete. To accomplish this, prestressed concrete specimens were locally corroded to different levels by anodic polarization and then polarized to -1.30 V SCE. A procedure of examination was developed using strain gauges to determine the level of prestrain. Relatively few brittle failures of wires resulted due, at least in part, to a relatively low prestrain of the pretensioned tendons. A model was developed which, coupled with data from parallel research, permitted definition of the minimum cross section for brittle failure as a function of the magnitude of prestrain and corrosion morphology of the wire. These results were tabulated in a format that can be used during field inspection to identify structural elements for which fracture could occur upon application of cathodic protection.
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Date Issued: 1997
PURL: http://purl.flvc.org/fcla/dt/15417
Subject Headings: Prestressed concrete--Corrosion, Cathodic protection, Prestressed concrete--Embrittlement, Prestressed steel construction
Format: Document (PDF)

Title: Hydrogen embrittlement of cathodically protected prestressing steel.
Creator: Kliszowski, Stanislas Henri., Florida Atlantic University, Hartt, William H., College of Engineering and Computer Science, Department of Ocean and Mechanical Engineering
Abstract/Description: Cathodic protection is currently recognized as the most practical mean for arresting corrosion of reinforcing steel tendons in existing concrete structures, however, its appropriateness in the case of prestressed concrete is questioned because prestressing steels are relatively susceptible to environmental cracking (hydrogen embrittlement). For the purpose of studying embrittlement tendencies a series of experiments using the slow strain rate technique were performed. The susceptibility to...
Show moreCathodic protection is currently recognized as the most practical mean for arresting corrosion of reinforcing steel tendons in existing concrete structures, however, its appropriateness in the case of prestressed concrete is questioned because prestressing steels are relatively susceptible to environmental cracking (hydrogen embrittlement). For the purpose of studying embrittlement tendencies a series of experiments using the slow strain rate technique were performed. The susceptibility to environmental cracking was compared for different steels corresponding to ASTM grades 270 and 250 polarized at $-$900 and $-1300$ mV (SCE) in deaerated saturated Ca(OH)$\sb2$ solutions. The influence of different notch and pit geometries was studied to simulate the behavior of corroded tendons and investigate the transition between smooth and severely notched specimen behavior. Also evaluated was the evolution of the mechanical properties of tendons after excessive polarization. The different cracking processes are discussed based on test data, fractography and exposures conditions associated with concrete structures.
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Date Issued: 1994
PURL: http://purl.flvc.org/fcla/dt/14999
Subject Headings: Cathodic protection, Metals--Hydrogen embrittlement, Tendons (Prestressed concrete), Prestressed concrete--Deterioration, Prestressed steel construction
Format: Document (PDF)

Title: Influence of direct electrical current upon specific volume of mortar in sea water.
Creator: Le Floch, Anne., Florida Atlantic University, Hartt, William H., College of Engineering and Computer Science, Department of Ocean and Mechanical Engineering
Abstract/Description: Hollow, cylindrical mortar specimens of 0.4 water-cement ratio were prepared without reinforcement and exposed to flowing natural sea water for periods up to one year. Direct currents of 2, 10 and 50 mA were impressed between a mixed metal-oxide titanium substrate electrode positioned within each of these two zones, with a different electrolyte supply and exhaust for the cylinder core and exterior surface. Linear expansion of the specimens was evaluated as a function of exposure duration from...
Show moreHollow, cylindrical mortar specimens of 0.4 water-cement ratio were prepared without reinforcement and exposed to flowing natural sea water for periods up to one year. Direct currents of 2, 10 and 50 mA were impressed between a mixed metal-oxide titanium substrate electrode positioned within each of these two zones, with a different electrolyte supply and exhaust for the cylinder core and exterior surface. Linear expansion of the specimens was evaluated as a function of exposure duration from the output of embedded strain gages and from dimensional measurement of cylinder length and diameter. It was found that expansion of specimens exposed to direct current exceeded baseline ones (no current). Also, the expansion was anisotropic in that different magnitudes and trends were apparent for the diameter versus length directions. The expansion under free exposure (no current) was determined to be a function of specimen size and of the direction of measurement relative to the cast specimen face.
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Date Issued: 1995
PURL: http://purl.flvc.org/fcla/dt/15214
Subject Headings: Concrete--Deterioration, Concrete--Corrosion, Seawater corrosion, Cathodic protection
Format: Document (PDF)

Title: AN INVESTIGATION OF POTENTIAL, PH AND CALCAREOUS DEPOSITS WITHIN SIMULATED FATIGUE CRACKS FOR CATHODICALLY POLARIZED STRUCTURAL STEEL IN SEA WATER.
Creator: MAO, WEI-YUN., Florida Atlantic University, Hartt, William H., College of Engineering and Computer Science, Department of Ocean and Mechanical Engineering
Abstract/Description: Electrochemical conditions within corrosion fatigue cracks are thought to exert an important influence upon propagation rate. For the case of cathodically polarized steel in sea water, it has been observed that pH of electrolyte adjacent to steel increased and calcareous material formed on the steel surface. As a consequence of the latter process the electrochemistry within cathodically polarized cracks may be unique compared to other electrolytes. The objective of this study has been to...
Show moreElectrochemical conditions within corrosion fatigue cracks are thought to exert an important influence upon propagation rate. For the case of cathodically polarized steel in sea water, it has been observed that pH of electrolyte adjacent to steel increased and calcareous material formed on the steel surface. As a consequence of the latter process the electrochemistry within cathodically polarized cracks may be unique compared to other electrolytes. The objective of this study has been to measure the potential and pH within simulated fatigue cracks of ABS DH 32 steel under cathodic protection. In addition, the calcareous deposits which formed within the simulated cracks were observed and analyzed. Based upon these data, potential, pH profiles and calcareous deposit thickness and composition were measured. This, in turn, permitted conditions within the simulated crack to be better understood.
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Date Issued: 1984
PURL: http://purl.flvc.org/fcla/dt/14208
Subject Headings: Steel, Structural--Testing, Cathodic protection, Electrolytic corrosion
Format: Document (PDF)

Title: Steel cathodic polarization and calcareous deposit characteristics in deep seawater.
Creator: Chen, Shaowei., Florida Atlantic University, Hartt, William H., College of Engineering and Computer Science, Department of Ocean and Mechanical Engineering
Abstract/Description: Field and laboratory ambient and simulated deep seawater sacrificial anode cathodic protection experiments were performed by coupling steel specimens to Al-Zn-Hg anode through an appropriately sized external resistor and thereby permitting a particular level of cathodic protection from freely corroding to overprotection to be simulated. The effects of sea current velocity, surface preparation, initial current density, temperature and hydrostatic pressure upon cathodic polarization and...
Show moreField and laboratory ambient and simulated deep seawater sacrificial anode cathodic protection experiments were performed by coupling steel specimens to Al-Zn-Hg anode through an appropriately sized external resistor and thereby permitting a particular level of cathodic protection from freely corroding to overprotection to be simulated. The effects of sea current velocity, surface preparation, initial current density, temperature and hydrostatic pressure upon cathodic polarization and characteristics of calcareous deposits were investigated in the context of slope parameter and steady-state potential and current density trend. The results revealed that a linear relationship between cathode potential and current density is applicable for design of sacrificial anode cathodic protection systems and analysis of cathodic protection survey data from existing structures both in shallow and deep waters. It was also found that for cathodically polarized steel specimens in ambient (shallow) seawater steady-state cathode potential and current density varied according to a sigmoidal trend that indicates the importance of calcareous deposits in such exposures and demonstrated the utility of rapid polarization. On the other hand, no sigmoidal trend was apparent for field and simulated deep water tests; but instead steady-state current density was constant for potential range between -0.80 and -1.05 v (Ag/AgCl). This disclosed that no particular benefit could be derived from employing rapid polarization in cold water exposures. SEM, EDX and X-ray diffraction analysis revealed that the calcareous deposits formed upon specimens exposed at 5C and ambient pressure or 8.96 MPa laboratory experiments exhibited two layer structures--an outer layer of CaCO3 as aragonite and inner layer of Mg(OH)2 as brucite. The morphology and coverage of the deposits depended on the design slope parameter (initial current density). Field testing results indicated that deposits were also composed of CaCO3 and Mg(OH)2 where the former was calcite. Because of the poor coverage of the deposits formed in the deep water condition, limited current density reduction was noted. These results suggest that a different cp design approach and strategy should be considered for deep, cold seawater compared to that commonly used in shallow water environments.
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Date Issued: 1996
PURL: http://purl.flvc.org/fcla/dt/12457
Subject Headings: Seawater corrosion, Cathodic protection, Steel--Corrosion
Format: Document (PDF)

Title: STUDY OF ELECTROCHEMISTRY MODIFICATIONS WITHIN CATHODICALLY PROTECTED FATIGUE CREVICES IN 3% SODIUM-CHLORIDE - DISTILLED WATER SOLUTION AND SEAWATER.
Creator: RAJPATHAK, SHIRISH SHRIDHAR., Florida Atlantic University, Hartt, William H., College of Engineering and Computer Science, Department of Ocean and Mechanical Engineering
Abstract/Description: It is well recognized that the electrochemistry modifications within cathodically protected fatigue crevices in seawater has pronounced effect on crack growth rate. This study focuses its attention on potential distribution within simulated fatigue crevice as a function of electrolyte velocity, fatigue frequency and cathodic protection potential. Results of salt water electrolyte and seawater electrolyte are compared to bring about the effect of calcareous deposits, Finally, a mathematical...
Show moreIt is well recognized that the electrochemistry modifications within cathodically protected fatigue crevices in seawater has pronounced effect on crack growth rate. This study focuses its attention on potential distribution within simulated fatigue crevice as a function of electrolyte velocity, fatigue frequency and cathodic protection potential. Results of salt water electrolyte and seawater electrolyte are compared to bring about the effect of calcareous deposits, Finally, a mathematical model based on mass transfer laws is developed to rationalise potential distribution trends within fatigue crevice and are compared with the observed behaviour.
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Date Issued: 1983
PURL: http://purl.flvc.org/fcla/dt/14151
Subject Headings: Cathodic protection, Metals--Corrosion fatigue, Sea-water corrosion
Format: Document (PDF)

Title: A STUDY OF THE EFFECT OF FLOW PARAMETERS ON THE CATHODIC PROTECTION OF A STEEL PLATE IN NATURAL SEAWATER.
Creator: MCCABE, KEVIN MICHAEL., Florida Atlantic University, Smith, Samuel W., College of Engineering and Computer Science, Department of Ocean and Mechanical Engineering
Abstract/Description: The influence of hydrodynamic parameters and cathodic polarization on the formation of calcareous deposits on a steel plate in flowing seawater is investigated. Current density variations on the plate are determined for a combination of applied potentials and seawater velocities. Equations are developed to relate the cathodic current density distribution to variations in hydrodynamic and diffusional boundary layer thickness along the plate for laminar and turbulent flow regimes. A comparison...
Show moreThe influence of hydrodynamic parameters and cathodic polarization on the formation of calcareous deposits on a steel plate in flowing seawater is investigated. Current density variations on the plate are determined for a combination of applied potentials and seawater velocities. Equations are developed to relate the cathodic current density distribution to variations in hydrodynamic and diffusional boundary layer thickness along the plate for laminar and turbulent flow regimes. A comparison of experimental current densities on a bare plate to that predicted by theory is examined. Effects of flow on the formation and properties of calcareous deposits are discussed in light of recent developments in marine cathodic protection.
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Date Issued: 1984
PURL: http://purl.flvc.org/fcla/dt/14192
Subject Headings: Plates, Iron and steel--Cathodic protection, Carbon steel--Corrosion, Plates, Iron and steel--Fluid dynamics, Cathodic protection
Format: Document (PDF)

Seawater corrosion (3)	+ -
Prestressed steel construction (2)	+ -
Sea-water corrosion (2)	+ -
Steel--Corrosion (2)	+ -
Tendons (Prestressed concrete) (2)	+ -

Adhesives (1)	+ -
Carbon steel--Corrosion (1)	+ -
Concrete--Corrosion (1)	+ -
Concrete--Deterioration (1)	+ -
Corrosion and anti-corrosives (1)	+ -
Electrolytic corrosion (1)	+ -
Finite element method (1)	+ -
Marine steel (1)	+ -
Metals--Corrosion fatigue (1)	+ -
Metals--Hydrogen embrittlement (1)	+ -
Ocean currents (1)	+ -
Offshore structures (1)	+ -
Plates, Iron and steel--Cathodic protection (1)	+ -
Plates, Iron and steel--Fluid dynamics (1)	+ -
Prestressed concrete--Corrosion (1)	+ -
Prestressed concrete--Deterioration (1)	+ -
Prestressed concrete--Embrittlement (1)	+ -
Prevention (1)	+ -
Reinforced concrete--Corrosion (1)	+ -
Steel, Structural--Testing (1)	+ -
Steel--Embrittlement (1)	+ -
Zinc coating (1)	+ -

College of Engineering and Computer Science (12)	+ -
Florida Atlantic University (12)	+ -
Hartt, William H. (10)	+ -
Chen, Shaowei. (1)	+ -
Gantiva, Nicolas. (1)	+ -

Kliszowski, Stanislas Henri. (1)	+ -
Le Floch, Anne. (1)	+ -
Lemieux, Edward John. (1)	+ -
Luo, Jiunn-Shyong (1)	+ -
MAO, WEI-YUN. (1)	+ -
MCCABE, KEVIN MICHAEL. (1)	+ -
Poeydomenge, Arnaud. (1)	+ -
RAJPATHAK, SHIRISH SHRIDHAR. (1)	+ -
Sigonney, Yann Manuel. (1)	+ -
Smith, Samuel W. (1)	+ -
Stauder, Anne-Laure T. (1)	+ -

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