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Title: INFLUENCE OF DISSOLVED ORGANICS IN SEA WATER ON THE CORROSION BEHAVIOR OF SELECTED METALS.
Creator: MACDOWELL, LOUIS GARDNER, III, Florida Atlantic University
Abstract/Description: Corrosion experiments have been performed upon steel and copper in natural sea water, photo-oxidized sea water and 3.5% sodium chloride-distilled water solutions. Anodic and cathodic polarization scans were conducted, and the resulting curves were employed to characterize corrosion behavior in each of the electrolytes. While little difference as a function of electrolyte was noted for tests upon copper, variations were apparent in the case of steel. The effect of environment has been...
Show moreCorrosion experiments have been performed upon steel and copper in natural sea water, photo-oxidized sea water and 3.5% sodium chloride-distilled water solutions. Anodic and cathodic polarization scans were conducted, and the resulting curves were employed to characterize corrosion behavior in each of the electrolytes. While little difference as a function of electrolyte was noted for tests upon copper, variations were apparent in the case of steel. The effect of environment has been interpreted in terms of differences in organics adsorbed upon the metal surface from one electrolyte to the next. Significance of adsorbed organics upon corrosion rate of steel in sea water is discussed.
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Date Issued: 1979
PURL: http://purl.flvc.org/fcla/dt/13957
Subject Headings: Seawater corrosion
Format: Document (PDF)

Title: THE CORROSION OF EPOXY COATED REINFORCING STEEL.
Creator: WANG, YUN TSO, Florida Atlantic University
Abstract/Description: Tests were conducted using 10 cm. (3.93 in.) lengths of both epoxy coated and bare steel reinforcing rods in simulated concrete environments of varying pH and chloride ion levels. Polarization studies using cathodic scan techniques were used to characterize the quality of the epoxy coating. In all the environments tested, bars with more defects required larger currents at a given potential than did the bars with few defects. Corrosion potential measurements in passive environments showed...
Show moreTests were conducted using 10 cm. (3.93 in.) lengths of both epoxy coated and bare steel reinforcing rods in simulated concrete environments of varying pH and chloride ion levels. Polarization studies using cathodic scan techniques were used to characterize the quality of the epoxy coating. In all the environments tested, bars with more defects required larger currents at a given potential than did the bars with few defects. Corrosion potential measurements in passive environments showed significant fluctuations from day to day, making it difficult to use potential measurement for corrosion characterization. Galvanic couples between epoxy coated and uncoated bars indicated that galvanic currents increased as the differences in the corrosion potentials increased and also as the chloride ion content of the environment increased from 0 to 0.05 M.
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Date Issued: 1980
PURL: http://purl.flvc.org/fcla/dt/14010
Subject Headings: Concrete--Corrosion, Seawater Corrosion
Format: Document (PDF)

Title: INVESTIGATION OF CORROSION OF REINFORCING STEEL BY USING ULTRASONIC TECHNIQUES AND SPECTRAL ANALYSIS.
Creator: WANG, YUN YU, Florida Atlantic University
Abstract/Description: In this investigation an ultrasonic technique and spectral analysis were employed to detect corrosion of reinforcing steel in concrete under conditions of accelerated testing. Various properties of a transmitted ultrasonic pulse were determined, and it was concluded that the transfer function provided the most realistic possibility for detection of corrosion and cracking. The most meaningful correlations of the transfer function with corrosion and cracking events were for situations where the...
Show moreIn this investigation an ultrasonic technique and spectral analysis were employed to detect corrosion of reinforcing steel in concrete under conditions of accelerated testing. Various properties of a transmitted ultrasonic pulse were determined, and it was concluded that the transfer function provided the most realistic possibility for detection of corrosion and cracking. The most meaningful correlations of the transfer function with corrosion and cracking events were for situations where the temporal variation of the transfer function at the particular frequency was small. The appropriateness of ultrasonic parameters with regard to problems involving corrosion of reinforcing steel is discussed.
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Date Issued: 1979
PURL: http://purl.flvc.org/fcla/dt/14006
Subject Headings: Concrete--Corrosion, Seawater Corrosion
Format: Document (PDF)

Title: FREQUENCY DEPENDENCE OF SEA WATER CORROSION FATIGUE OF NOTCHED 1018 STEEL.
Creator: HENKE, THOMAS ELMER, Florida Atlantic University
Abstract/Description: Experiments were conducted to investigate frequency dependence of sea water corrosion fatigue of notched 1018 steel under constant deflection, reverse bend test conditions. Frequencies of 1850, 1200, and 600 cycles per minute (CPM) were studied. Results indicate that frequency effects are not observed at high stresses, apparently due to the mechanical damage component of the fatigue process dominating over corrosion considerations. At low stresses reduced frequency resulted in decreased...
Show moreExperiments were conducted to investigate frequency dependence of sea water corrosion fatigue of notched 1018 steel under constant deflection, reverse bend test conditions. Frequencies of 1850, 1200, and 600 cycles per minute (CPM) were studied. Results indicate that frequency effects are not observed at high stresses, apparently due to the mechanical damage component of the fatigue process dominating over corrosion considerations. At low stresses reduced frequency resulted in decreased cycles to failure. Acidification of the crack tip solution is proposed as possibly responsible for this behavior. For specimens subjected to equal stress levels in the frequency dependent region, greater cathodic protection is required to mitigate corrosion fatigue for 600 CPM specimens (-0.86 volts standard calomel electrode) (V SCE) than for 1850 CPM specimens (-079V SCE).
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Date Issued: 1975
PURL: http://purl.flvc.org/fcla/dt/13731
Subject Headings: Steel--Corrosion, Seawater
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: Environmental cracking susceptibility of austenitic stainless steel alloys in acidified seawater.
Creator: Poulassichidis, Antonios N., Florida Atlantic University, Lipka, Stephen M., College of Engineering and Computer Science, Department of Ocean and Mechanical Engineering
Abstract/Description: The stress corrosion cracking susceptibility of austenitic stainless steels SS304L, SS316L and SS904L was studied in an acidified seawater environment by slow strain rate testing at 24, 38 and 66$\sp\circ$C. Fractographic evidence of SCC susceptibility was obtained using scanning electron microscopy. The degree of susceptibility to SCC for each alloy in these environments is discussed based on the mechanical parameters, fractography and anodic polarization behavior. The results showed that...
Show moreThe stress corrosion cracking susceptibility of austenitic stainless steels SS304L, SS316L and SS904L was studied in an acidified seawater environment by slow strain rate testing at 24, 38 and 66$\sp\circ$C. Fractographic evidence of SCC susceptibility was obtained using scanning electron microscopy. The degree of susceptibility to SCC for each alloy in these environments is discussed based on the mechanical parameters, fractography and anodic polarization behavior. The results showed that SS904L performed better than SS304L and SS316L in the aforementioned environments.
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Date Issued: 1994
PURL: http://purl.flvc.org/fcla/dt/15071
Subject Headings: Stress corrosion, Seawater corrosion, Alloys--Stress corrosion
Format: Document (PDF)

Title: Effect of strain rate and temperature on the stress corrosion cracking tendency of engineering alloys in acidified seawater.
Creator: Kundalgurki, Srivatsa G., Florida Atlantic University, Lipka, Stephen M., College of Engineering and Computer Science, Department of Ocean and Mechanical Engineering
Abstract/Description: The stress corrosion cracking (SCC) tendencies of several engineering alloys were studied in an acidified seawater environment as a function of applied strain rate and electrolyte temperature. The selected alloys included austenitic stainless steels 304L, 316L, 904L and A-286 (an iron-based superalloy at two heat treatments yielding ultimate tensile strengths of 130 and 200 ksi), Inconel 718 (220 ksi ultimate tensile strength) and Hastelloys C-22 and C-276. The slow strain rate test technique...
Show moreThe stress corrosion cracking (SCC) tendencies of several engineering alloys were studied in an acidified seawater environment as a function of applied strain rate and electrolyte temperature. The selected alloys included austenitic stainless steels 304L, 316L, 904L and A-286 (an iron-based superalloy at two heat treatments yielding ultimate tensile strengths of 130 and 200 ksi), Inconel 718 (220 ksi ultimate tensile strength) and Hastelloys C-22 and C-276. The slow strain rate test technique was used to evaluate the SCC strain rate dependency of each alloy at extension rates of 4.7 x 10^-6, 4.7 x 10^-4 and 4.7 x 10^-3 mm/sec. The effect of electrolyte temperature was evaluated at 38C and 60C at a single extension rate of 4.7 x 10^-5 mm/sec. Control specimens were tested in a laboratory air environment at an extension rate of 4.7 x 10^-5 mm/sec. Various mechanical parameters of the specimens tested in the corrosive medium were compared with those of control specimens to quantify the degree of cracking. Fractographic evidence of SCC was obtained using scanning electron microscopy (SEM). An attempt was made to correlate SCC tendency with the alloy's passivation kinetics and microstructure. Atmospheric exposure testing was performed in a simulated space shuttle launch pad environment for selected alloys.
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Date Issued: 1992
PURL: http://purl.flvc.org/fcla/dt/14853
Subject Headings: Alloys--Stress corrosion, Stress corrosion, Sea-water corrosion
Format: Document (PDF)

Title: CHARACTERIZATION OF THE EMBRITTLEMENT TENDENCY OF A CATHODICALLY POLARIZED SUPERFERRITIC STAINLESS STEEL IN SEAWATER (HYDROGEN DAMAGE, INTERGRANULAR).
Creator: KRISHNAMURTHY, RAVI M., Florida Atlantic University, Hartt, William H., College of Engineering and Computer Science, Department of Ocean and Mechanical Engineering
Abstract/Description: In order to investigate the cracking tendency of cathodically polarized SEACURE superferritic stainless steel, a series of potentiostatically controlled tests were conducted in flowing natural seawater. U-bend and tensile specimens were used to determine the threshold potential and limiting fracture stress. The microstructure was examined using a metallurgical microscope and a chemical analysis was conducted across the grain boundary. These results were then correlated to hydrogen assisted...
Show moreIn order to investigate the cracking tendency of cathodically polarized SEACURE superferritic stainless steel, a series of potentiostatically controlled tests were conducted in flowing natural seawater. U-bend and tensile specimens were used to determine the threshold potential and limiting fracture stress. The microstructure was examined using a metallurgical microscope and a chemical analysis was conducted across the grain boundary. These results were then correlated to hydrogen assisted cracking, by performing SEM and EDAX analyses on fractured U-bend and tensile samples. Finally a model was developed which explained the predominantly intergranular cracking in the static stress condition and also accommodated the transgranular failure during dynamic loading.
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Date Issued: 1986
PURL: http://purl.flvc.org/fcla/dt/14325
Subject Headings: Steel--Fracture, Sea-water corrosion
Format: Document (PDF)

Title: Cathodic polarization behavior of mild steel exposed to selected flow velocities and slope parameters in natural seawater.
Creator: Hugus, G. Dickson, IV., Florida Atlantic University, Hartt, William H.
Abstract/Description: Twenty-four test cells arranged in a pipe flow setup were assembled to investigate the effect of seawater velocity on the polarization behavior of galvanically polarized mild steel. Each 1023 steel pipe specimen of 10.8 em ID was coupled via a current limiting resistor to a mercury activated aluminum anode and exposed to a velocity of either 0.03, 0.09 or 0.30 m/s. The resistors were sized such that polarization was controlled according to one of six slope parameters. Steady state potential...
Show moreTwenty-four test cells arranged in a pipe flow setup were assembled to investigate the effect of seawater velocity on the polarization behavior of galvanically polarized mild steel. Each 1023 steel pipe specimen of 10.8 em ID was coupled via a current limiting resistor to a mercury activated aluminum anode and exposed to a velocity of either 0.03, 0.09 or 0.30 m/s. The resistors were sized such that polarization was controlled according to one of six slope parameters. Steady state potential and maintenance current density values were determined, and a steady state potential vs. current density curve was established for specimens in each velocity. Some specimens experienced a rise in cathode potential and current density after an apparent steady state had been reached. This was probably related to the influence of velocity on the protectiveness of the calcareous deposit. Of the specimens that experienced a rise in steady state potential and current density, a few were later observed to decrease in potential and current density and reach steady state. Steady state current density vs. velocity plots of specimens at steady state potentials of -0.78, -0.88 and -0.98 V showed that current density was directly proportional to velocity as well as relatively insensitive to potential. Ficks' first law was utilized in conjunction with an empirically derived dimensionless correlation that characterizes the behavior between fluid velocity and mass transfer of molecular species from the bulk solution to the cathode surface in turbulent seawater pipe flow. Calcareous deposit porosity constants were calculated and it was surmised that as velocity increased by a factor of three, the porosity of the deposits near 0.78 and -0.89 V increased by multiples of about two on average. Porosity at the above potentials increased with decreasing potential by a factor of a little over two. SEM micrographs were made and EDX analyses were performed on the calcareous deposits of selected specimens.
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Date Issued: 1997
PURL: http://purl.flvc.org/fcla/dt/15501
Subject Headings: Cathodic protection, Seawater corrosion, Marine steel
Format: Document (PDF)

Title: Analytical evaluation of marine concrete pile repairs.
Creator: Saleh, Zaher A. Abou., Florida Atlantic University, Reddy, Dronnadula V., College of Engineering and Computer Science, Department of Civil, Environmental and Geomatics Engineering
Abstract/Description: The purpose of the thesis is to determine and compare the performance characteristics of marine piles corroded by chloride diffusion and repaired by several different methods for both uncracked and cracked concrete and to determine their structural integrity. The long-term objective is the comparison of the analytical values with those from an on-going experimental evaluation. The time for chloride concentration reach the threshold value that initiates corrosion in the reinforcement has been...
Show moreThe purpose of the thesis is to determine and compare the performance characteristics of marine piles corroded by chloride diffusion and repaired by several different methods for both uncracked and cracked concrete and to determine their structural integrity. The long-term objective is the comparison of the analytical values with those from an on-going experimental evaluation. The time for chloride concentration reach the threshold value that initiates corrosion in the reinforcement has been determined by Fick's law, extended to 2-D and 3-D chloride diffusion, for (a) uncracked concrete, and (b) for cracked concrete with the Simplified Smeared Approach (SSA). The structural integrity of the concrete circular pile is compared before and alter repair, by (a) finite element modeling using ANSYS software with the maximum deflection, and (b) beam strength analysis to find the moment capacity for cracked and ultimate conditions. The overall findings indicate the adequacy of the repair procedures.
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Date Issued: 2003
PURL: http://purl.flvc.org/fcla/dt/13062
Subject Headings: Concrete piling, Reinforced concrete--Corrosion, Seawater 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: pH determination of concrete pore water by a leaching technique for various concrete mixtures.
Creator: Sitton, Izic., Florida Atlantic University, Hartt, William H., College of Engineering and Computer Science, Department of Ocean and Mechanical Engineering
Abstract/Description: A pH determination technique of concrete pore water by means of leaching OH- ions from powdered samples was developed. This method was then evaluated in terms of sample size, extent of dilution, leaching period, the type of leaching, calcium hydroxide error, and titration scatter. Based upon variations of the above parameters it was concluded that a maximum amount of hydroxide ions was released into solution for samples with the smallest particle size within a 24 hours static leaching period....
Show moreA pH determination technique of concrete pore water by means of leaching OH- ions from powdered samples was developed. This method was then evaluated in terms of sample size, extent of dilution, leaching period, the type of leaching, calcium hydroxide error, and titration scatter. Based upon variations of the above parameters it was concluded that a maximum amount of hydroxide ions was released into solution for samples with the smallest particle size within a 24 hours static leaching period. A 50ml dilution volume proved optimum with regard to filtration and titration. Under the above circumstances calcium hydroxide dissolution did not seem to pose a significant source of error. Furthermore, repeatability of the measurements was good and titration scatter was determined to be about 0.05 pH units. This method was used to determine the pH of samples containing different amounts of fly ash or silica fume additions as well as plain cement (control) samples. A drop in OH- concentration, that is pH, was detected with increasing pozzolanic addition. The results are discussed with the context of the degree of corrosion mitigation afforded by these pozzolans.
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Date Issued: 1996
PURL: http://purl.flvc.org/fcla/dt/15364
Subject Headings: Concrete--Corrosion, Seawater corrosion, Concrete--Testing, Leaching
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: 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.
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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: 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: 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.
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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).
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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: 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.
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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: AN ASPECT OF THE LIMITING CURRENT DENSITY ALONG THE CIRCUMFERENCE OF A STEEL CYLINDER BY THE EFFECT OF THE FLOW VELOCITY (CATHODIC PROTECTION, CIRCULAR, BOUNDARY LAYER THICKNESS).
Creator: WANG, TIEN-JEN., 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 limiting current density by cathodic protection on a steel cylinder in flowing water is investigated. The limiting current density variations along the circumference of a circular cylinder are determined for different flow velocities. Several methods are also used to relate the cathodic current density distribution to variations in hydrodynamic and diffusional boundary layer thickness along the circumference of the cylinder for laminar and...
Show moreThe influence of hydrodynamic parameters and limiting current density by cathodic protection on a steel cylinder in flowing water is investigated. The limiting current density variations along the circumference of a circular cylinder are determined for different flow velocities. Several methods are also used to relate the cathodic current density distribution to variations in hydrodynamic and diffusional boundary layer thickness along the circumference of the cylinder for laminar and turbulent flow regimes. a comparison of experimental current densities on a cylinder to that predicated by theory is also examined.
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Date Issued: 1986
PURL: http://purl.flvc.org/fcla/dt/14316
Subject Headings: Steel--Cathodic protection, Sea-water corrosion
Format: Document (PDF)

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)

Seawater corrosion (11)	+ -
Sea-water corrosion (10)	+ -
Cathodic protection (7)	+ -
Corrosion and anti-corrosives (5)	+ -
Concrete--Corrosion (4)	+ -

Alloys--Stress corrosion (2)	+ -
Marine steel (2)	+ -
Offshore structures (2)	+ -
Seawater Corrosion (2)	+ -
Steel--Corrosion (2)	+ -
Steel--Fatigue (2)	+ -
Steel--Fracture (2)	+ -
Stress corrosion (2)	+ -
Adhesives (1)	+ -
Chlorides (1)	+ -
Concrete beams--Fatigue (1)	+ -
Concrete piling (1)	+ -
Concrete--Additives (1)	+ -
Concrete--Deterioration (1)	+ -
Concrete--Testing (1)	+ -
Finite element method (1)	+ -
Leaching (1)	+ -
Limekilns--Testing (1)	+ -
Marine steel--Fatigue (1)	+ -
Metals--Corrosion fatigue (1)	+ -
Plates, Iron and steel--Cathodic protection (1)	+ -
Prevention (1)	+ -
Reinforced concrete construction (1)	+ -
Reinforced concrete--Corrosion (1)	+ -
Reinforced concrete--Deterioration (1)	+ -

Florida Atlantic University (25)	+ -
College of Engineering and Computer Science (15)	+ -
Department of Ocean and Mechanical Engineering (14)	+ -
Hartt, William H. (12)	+ -
Reddy, Dronnadula V. (3)	+ -

Lipka, Stephen M. (2)	+ -
Smith, Samuel W. (2)	+ -
Ahn, Woo-Suk. (1)	+ -
Alvarez, Marcelina (1)	+ -
Badve, Ashwin P. (1)	+ -
Chaix, Olivier. (1)	+ -
Chen, Shaowei. (1)	+ -
Davidson, Keith Dewayne. (1)	+ -
Department of Civil, Environmental and Geomatics Engineering (1)	+ -
Gantiva, Nicolas. (1)	+ -
HENKE, THOMAS ELMER (1)	+ -
Haratt, William H. (1)	+ -
Hugus, G. Dickson, IV. (1)	+ -
KRISHNAMURTHY, RAVI M. (1)	+ -
Kundalgurki, Srivatsa G. (1)	+ -
Le Floch, Anne. (1)	+ -
Luo, Jiunn-Shyong (1)	+ -
MACDOWELL, LOUIS GARDNER, III (1)	+ -
Poulassichidis, Antonios N. (1)	+ -
RAJPATHAK, SHIRISH SHRIDHAR. (1)	+ -
SLOAN, FORREST EUGENE. (1)	+ -
Saleh, Zaher A. Abou. (1)	+ -
Sitton, Izic. (1)	+ -
Tanner, Russell (1)	+ -
VARGHESE, BABU. (1)	+ -

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