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Title: Obstruction of chloride diffusion in concrete by embedded reinforcing bars.
Creator: Cros, Pascal., Florida Atlantic University, Hartt, William H.
Abstract/Description: A study was performed of the effect of reinforcing bars on chloride diffusion into concrete. These bars act as obstacles to chloride movement, and this obstruction allows the chloride concentration to build-up faster along the top of the reinforcing bar than elsewhere. As a consequence, the critical chloride threshold to initiate corrosion of the steel is reached sooner than otherwise expected. This research was performed using two different methods. First, chloride analyses were performed on...
Show moreA study was performed of the effect of reinforcing bars on chloride diffusion into concrete. These bars act as obstacles to chloride movement, and this obstruction allows the chloride concentration to build-up faster along the top of the reinforcing bar than elsewhere. As a consequence, the critical chloride threshold to initiate corrosion of the steel is reached sooner than otherwise expected. This research was performed using two different methods. First, chloride analyses were performed on chloride exposed concrete blocks by taking cores in the concrete and drillings along the trace of the top bars. Second, concrete blocks models were analyzed by finite element analysis and the effect of the obstruction by the bar quantified. The role of the reinforcing bar in the chloride diffusional flow is discussed considering these two methods.
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Date Issued: 2005
PURL: http://purl.flvc.org/fcla/dt/13239
Subject Headings: Reinforcing bars--Corrosion, Reinforced concrete construction--Corrosion, Concrete--Additives, Chlorides--Diffusion rate
Format: Document (PDF)

Title: A STUDY OF STRESS CORROSION CRACKING IN 7079-T651 ALUMINUM.
Creator: FINNEGAN, JOHN EDMUND., Florida Atlantic University, Hartt, William H.
Abstract/Description: This study investigated the stress corrosion cracking behavior of aluminum alloy 7079 - T651 in two corrosive environments, sea water and a 3% NaCl-distilled water solution. Self stressing, double cantilever beam specimens were employed; and these were stressed at various levels, exposed in one of the two test environments and crack extension monitored as a function of time. Equations for the plane strain stress intensity factor (K1) were compared and evaluated, with respect to stress...
Show moreThis study investigated the stress corrosion cracking behavior of aluminum alloy 7079 - T651 in two corrosive environments, sea water and a 3% NaCl-distilled water solution. Self stressing, double cantilever beam specimens were employed; and these were stressed at various levels, exposed in one of the two test environments and crack extension monitored as a function of time. Equations for the plane strain stress intensity factor (K1) were compared and evaluated, with respect to stress intensities calculated from compliance measurements. Results suggest that stress intensity is not the only important variable controlling crack growth rate and a time dependent cracking mechanism may govern a portion of crack growth.
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Date Issued: 1975
PURL: http://purl.flvc.org/fcla/dt/13730
Subject Headings: Aluminum--Corrosion, Stress corrosion
Format: Document (PDF)

Title: INTERGRANULAR CORROSION OF 5086-H34 ALUMINUM.
Creator: DUNN, MICHAEL JOSEPH., Florida Atlantic University, Hartt, William H.
Abstract/Description: Experiments were carried out in order to better characterize the intergranular corrosion process of 5086-H34 aluminum in sea water. Specimens were exposed at a constant potential in the range -0.75VSCE
Show moreExperiments were carried out in order to better characterize the intergranular corrosion process of 5086-H34 aluminum in sea water. Specimens were exposed at a constant potential in the range -0.75VSCE < corr < -0.83 Volts Saturated Calomel Electrode (VSCE). As a result, it was found that for a potential noble to -0.79VSCE intergranular corrosion indeed occurs. Under the same conditions 5052-H34 shows no intergranular attack. Since the major difference between these alloys is beta phase percent and distribution, this implies a minimum of this phase is required for intergranular corrosion to occur. Measurements of pH within simulated occluded cells were made in an attempt to obtain reasons for the observed -0.79VSCE threshold. The results of this did not point to any particular course which would explain this potential.
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Date Issued: 1975
PURL: http://purl.flvc.org/fcla/dt/13752, http://purl.flvc.org/fau/fd/FADT13752
Subject Headings: Aluminum--Corrosion
Format: Document (PDF)

Title: CORROSION FATIGUE OF NOTCHED 1018 STEEL IN SEA WATER.
Creator: FLUET, JOSEPH E., JR., Florida Atlantic University, Hartt, William H.
Abstract/Description: A summary of some pertinent previous research by other authors is presented separately from the actual laboratory report. The report presents the results of air and corrosion fatigue tests which are. interpreted in terms of time to failure, crack growth history, and fracture mechanics techniques. In addition, the results of cathodic protection of corrosion fatigue tests are interpreted in terms of simple-design criteria, as well as relative to Critical Corrosion Rate Theory. One of the more...
Show moreA summary of some pertinent previous research by other authors is presented separately from the actual laboratory report. The report presents the results of air and corrosion fatigue tests which are. interpreted in terms of time to failure, crack growth history, and fracture mechanics techniques. In addition, the results of cathodic protection of corrosion fatigue tests are interpreted in terms of simple-design criteria, as well as relative to Critical Corrosion Rate Theory. One of the more significant results presented is the greater longevity of corrosion fatigue, as compared to air fatigue, notched specimens stressed within 10-15 KSI above the air endurance limit. Also, the potential required to cathodically protect such notched specimens is shown to be 50 mV lower than for comparable smooth specimens. Both phenomena are attributed in part to the lowering of crack pH to acidic levels in notched specimens.
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Date Issued: 1976
PURL: http://purl.flvc.org/fcla/dt/13768
Subject Headings: Steel--Fatigue, Steel--Corrosion, Steel--Fracture, Notched bar testing
Format: Document (PDF)

Title: CORROSION OF CONCRETE COVERED REINFORCING STEEL IN A MARINE ENVIRONMENT RESULTING FROM STRAY CURRENT AND GALVANIC COUPLING.
Creator: MILLER, RONALD LAWRENCE., Florida Atlantic University, Hartt, William H., College of Engineering and Computer Science, Department of Ocean and Mechanical Engineering
Abstract/Description: It is recognized that reinforced concrete structures are often susceptible to stray current corrosion damage. Experiments have been performed upon a reinforced concrete bridge model in sea water, and these indicate that 0.01 percent of stray direct current in this electrolyte may enter the structure. Alternating current may also contribute to corrosion of reinforcing steel, though experimental results reveal detection to be more difficult than for direct current. Two other sources of current...
Show moreIt is recognized that reinforced concrete structures are often susceptible to stray current corrosion damage. Experiments have been performed upon a reinforced concrete bridge model in sea water, and these indicate that 0.01 percent of stray direct current in this electrolyte may enter the structure. Alternating current may also contribute to corrosion of reinforcing steel, though experimental results reveal detection to be more difficult than for direct current. Two other sources of current in reinforcing steel are from cathodic protection systems of utility attachments and from galvanic coupling of the covered steel and bare steel. Mechanisms by which the above types of current contribute to deterioration of reinforced concrete structures are discussed.
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Date Issued: 1976
PURL: http://purl.flvc.org/fcla/dt/13772
Subject Headings: Steel--Corrosion
Format: Document (PDF)

Title: RESPONSE OF 1018 STEEL TO CONCURRENT CYCLIC LOADING AND CATHODIC POLARIZATION IN NATURAL SEA WATER.
Creator: HOOPER, WILLIAM CLARENCE., Florida Atlantic University, Hartt, William H.
Abstract/Description: Reverse bend, constant deflection fatigue experiments were conducted in natural sea water at 1850 cycles per minute (cpm) to investigate the response of 1018 notched steel to concurrent cyclic loading and cathodic polarization. For comparison purposes S-log N curves were also determined in air and high purity argon. These indicate that the endurance limit established in sea water by cathodic polarization at -0.85 volts, Saturated Calomel Electrode (SCE), is greater than in either air or argon...
Show moreReverse bend, constant deflection fatigue experiments were conducted in natural sea water at 1850 cycles per minute (cpm) to investigate the response of 1018 notched steel to concurrent cyclic loading and cathodic polarization. For comparison purposes S-log N curves were also determined in air and high purity argon. These indicate that the endurance limit established in sea water by cathodic polarization at -0.85 volts, Saturated Calomel Electrode (SCE), is greater than in either air or argon. Two mechanisms are considered as responsible for this behavior. 1. Presence of carbonate and hydroxide deposits coupled with increased alkalinity at non-propagating crack tips. 2. Adsorbed OH- layer at non-propagating crack tips.
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Date Issued: 1976
PURL: http://purl.flvc.org/fcla/dt/13781
Subject Headings: Steel--Testing
Format: Document (PDF)

Title: CRACKING OF CONCRETE DUE TO CORROSION OF VARIOUS EMBEDDED METALS.
Creator: TURNER, DEAN HUDSON., Florida Atlantic University, Hartt, William H., College of Engineering and Computer Science, Department of Ocean and Mechanical Engineering
Abstract/Description: The objective of this investigati.on was to contribute to the determination of a suitable metallic coating for steel reinforcement in concrete exposed to a marine environment and possibly to stray current. Concrete specimens embedded with steel, aluminum, cadmium, copper, molybdenum, nickel, and galvanized steel were exposed to sea water. Direct current was impressed on these to accelerate corrosion of the reinforcement so that cracking of the concrete could be observed within the time limit...
Show moreThe objective of this investigati.on was to contribute to the determination of a suitable metallic coating for steel reinforcement in concrete exposed to a marine environment and possibly to stray current. Concrete specimens embedded with steel, aluminum, cadmium, copper, molybdenum, nickel, and galvanized steel were exposed to sea water. Direct current was impressed on these to accelerate corrosion of the reinforcement so that cracking of the concrete could be observed within the time limit of the investigation. Aluminum, cadmium, copper, and nickel were found to have no beneficial effect on concrete cracking as compared to steel. In addition, no correlation between oxide-metal volume ratio and concrete time-to-cracking could be observed. It was found that corrosion of molybdenum has little or no tendency to crack concrete and its corrosion potential and active behavior approximates that of steel, indicating it may be an excellent coating.
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Date Issued: 1976
PURL: http://purl.flvc.org/fcla/dt/13820
Subject Headings: Reinforced concrete--Cracking, Underwater concrete construction, Reinforced concrete--Corrosion
Format: Document (PDF)

Title: EFFECTS OF NATURAL SEAWATER AND CATHODIC POLARIZATION OF HIGH CYCLE FATIGUE OF 5086-H34 ALUMINUM.
Creator: FLODDER, STEVEN PAUL., Florida Atlantic University, Hartt, William H.
Abstract/Description: High cycle fatigue tests were conducted using symmetrical center cracked plate specimens in air, sea water and constant potentials of -1.0V and -1.3V(SCE) at 20 Hz. (1200 cycles per minute) to determine what effect these environments had on crack growth rates, delta a/delta n (inches per cycle), of 5086-H34 aluminum when plotted against stress intensity range, delta K (Ksi root of in). Crack growth rates of 10^-8 inches per cycle were obtained which indicated that apparent threshold stress...
Show moreHigh cycle fatigue tests were conducted using symmetrical center cracked plate specimens in air, sea water and constant potentials of -1.0V and -1.3V(SCE) at 20 Hz. (1200 cycles per minute) to determine what effect these environments had on crack growth rates, delta a/delta n (inches per cycle), of 5086-H34 aluminum when plotted against stress intensity range, delta K (Ksi root of in). Crack growth rates of 10^-8 inches per cycle were obtained which indicated that apparent threshold stress intensities, delta K th, exist which are the same for air, sea water and a constant potential of -1.0V(SCE); however, under a constant potential of -1.3V(SCE) the threshold shifts to a significantly higher value. It was also observed that the different enviroments had a pronounced effect on crack growth rate only at low stress intensities. Several mechanisms are considered to explain this behavior.
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Date Issued: 1977
PURL: http://purl.flvc.org/fcla/dt/13859
Subject Headings: Aluminum--Testing, Aluminum--Fatigue
Format: Document (PDF)

Title: STRESS CORROSION CRACKING OF 7079-T651 ALUMINUM IN RESPONSE TO A CONSTANT STRESS INTENSITY.
Creator: SCOTT, DARWIN HAROLD, II., Florida Atlantic University, Hartt, William H., College of Engineering and Computer Science, Department of Ocean and Mechanical Engineering
Abstract/Description: Double cantilever beam specimens of 7079-T651 aluminum were subjected to low constant stress intensities in a sea water environment to determine the stress corrosion cracking response. In addition to a constant stress intensity some specimens were subjected to controlled, constant potentials. Despite the fact that all tests were in Region I of the crack growth rate-stress intensity curve, where the former has been projected to be very dependent upon the latter, a unique relationship between...
Show moreDouble cantilever beam specimens of 7079-T651 aluminum were subjected to low constant stress intensities in a sea water environment to determine the stress corrosion cracking response. In addition to a constant stress intensity some specimens were subjected to controlled, constant potentials. Despite the fact that all tests were in Region I of the crack growth rate-stress intensity curve, where the former has been projected to be very dependent upon the latter, a unique relationship between stress intensity and crack growth rate was not always indicated. Therefore, some variable other than stress intensity is assumed to control crack growth, particularly for the first several hundred hours of exposure. The observed behavior is discussed in terms of accepted theories of stress corrosion cracking in high strength aluminum alloys, including electrochemical dissolution and hydrogen embrittlement.
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Date Issued: 1977
PURL: http://purl.flvc.org/fcla/dt/13878
Subject Headings: Stress corrosion, Aluminum--Corrosion
Format: Document (PDF)

Title: THE MECHANISM OF CONCRETE CRACKING IN SEAWATER DUE TO EMBEDDED METAL CORROSION.
Creator: GRIMES, WILLIAM DARWIN., Florida Atlantic University, Hartt, William H.
Abstract/Description: Investigation of concrete-rebar interface conditions was conducted for the purpose of identifying governing parameters of the concrete cracking process in seawater. Experiments included an examination of chloride ion penetration, concrete pH as a function of metallic chloride concentration, and pH distribution within reinforced, impressed current specimens. Metal-concrete systems investigated included iron, molybdenum, cadmium, zinc, aluminum, copper, and nickel. Simplified models of the...
Show moreInvestigation of concrete-rebar interface conditions was conducted for the purpose of identifying governing parameters of the concrete cracking process in seawater. Experiments included an examination of chloride ion penetration, concrete pH as a function of metallic chloride concentration, and pH distribution within reinforced, impressed current specimens. Metal-concrete systems investigated included iron, molybdenum, cadmium, zinc, aluminum, copper, and nickel. Simplified models of the rebar corrosion process are presented in conjunction with electrochemical analysis of the projected interface chemistry. Results indicated that chlorinities greater than seawater concentration may occur as a result of potential gradients in reinforced concrete. Laboratory simulations of interface chemistry indicated that metallic and chloride ions may produce an acid pH in concrete solutions when present in sufficiently high concentrations. Heasurements of pH on the fracture face of impressed current corrosion specimens indicated localized acidic conditions can develop.
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Date Issued: 1977
PURL: http://purl.flvc.org/fcla/dt/13885
Subject Headings: Reinforced concrete--Corrosion
Format: Document (PDF)

Title: EFFECT OF CATHODIC POLARIZATION AND SEA WATER VELOCITY UPON CALCAREOUS DEPOSIT FORMATION ON MILD STEEL.
Creator: WOLFSON, STEPHEN LANCE., Florida Atlantic University, Hartt, William H.
Abstract/Description: To investigate environmental conditions which influence the type and formation of calcareous deposits, AISI 1010 steel specimens were exposed in sea water at constant velocities and controlled potentials. Chemistry and thickness of the deposits which formed as a result of cathodic polarization of steel in sea water were determined. These variables were found to be a function of velocity and controlled potential with film thickness decreasing as velocity increased for all potentials considered...
Show moreTo investigate environmental conditions which influence the type and formation of calcareous deposits, AISI 1010 steel specimens were exposed in sea water at constant velocities and controlled potentials. Chemistry and thickness of the deposits which formed as a result of cathodic polarization of steel in sea water were determined. These variables were found to be a function of velocity and controlled potential with film thickness decreasing as velocity increased for all potentials considered. This behavior is interpreted in terms of variations in pH at the metal surface. A mass transfer analysis is presented which projects the pH at the metal surface as a function of velocity and controlled potential. Scanning electron micrographs are also included to give information regarding the nature and type of deposits. The experimental results are discussed within the frame of accepted concepts of sea water cathodic protection.
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Date Issued: 1978
PURL: http://purl.flvc.org/fcla/dt/13954
Subject Headings: Cathodic protection
Format: Document (PDF)

Title: A FATIGUE STUDY OF HY-80 STEEL IN SEA WATER.
Creator: ADAMSON, JOHNNY DALE., Florida Atlantic University, Hartt, William H.
Abstract/Description: Fatigue tests were performed at low stresss intensity ranges upon precracxed HY-80 steel specimens in air and sea water, at stress ratios of 0.1 and 0.8 with and without cathodic protection. Crack growth. was found to be higher at R = 0.8 than R = 0.1. Also, the relative positioning of fatigue crack growth rate data for freely corroding and cathodically protected specimens reversed order cs R changed from 0.1 to 0.8. Threshold stress intensity ranges were found to be higher in sea water than...
Show moreFatigue tests were performed at low stresss intensity ranges upon precracxed HY-80 steel specimens in air and sea water, at stress ratios of 0.1 and 0.8 with and without cathodic protection. Crack growth. was found to be higher at R = 0.8 than R = 0.1. Also, the relative positioning of fatigue crack growth rate data for freely corroding and cathodically protected specimens reversed order cs R changed from 0.1 to 0.8. Threshold stress intensity ranges were found to be higher in sea water than in air. A comparison of the deltaKth for HY-80 was made with. that of other steels.
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Date Issued: 1979
PURL: http://purl.flvc.org/fcla/dt/13976
Subject Headings: Steel--Fatigue
Format: Document (PDF)

Title: A STRESS CONCENTRATION ANALYSIS OF SELECTED WELDS FROM FATIGUE SPECIMENS USING THE FINITE-ELEMENT METHOD.
Creator: NEROLICH, SHAUN MICHAEL., Florida Atlantic University, Hartt, William H., College of Engineering and Computer Science, Department of Ocean and Mechanical Engineering
Abstract/Description: The stress concentration which exists at the toe of an AWS class 'c' weld has been investigated by means of the finite element method. This type of weld is representative of that specified to join tubular members for offshore structures. Welded fatigue specimens were sectioned and the weld profile described in terms of 1) the weld toe radius (R), 2) the reinforcement angle (e) and 3) the filler metal height QH). A statistical analysis was performed to determine the correlation between R, e...
Show moreThe stress concentration which exists at the toe of an AWS class 'c' weld has been investigated by means of the finite element method. This type of weld is representative of that specified to join tubular members for offshore structures. Welded fatigue specimens were sectioned and the weld profile described in terms of 1) the weld toe radius (R), 2) the reinforcement angle (e) and 3) the filler metal height QH). A statistical analysis was performed to determine the correlation between R, e and H from which it was found that they are independent of each other. By use of the finite element method, trends were established for the effect each parameter has on the stress concentration at the weld toe. Analysis of the effect of undercutting was also perfonned and the results used to offer an explanation why fatigue cracks propagate to failure in some cases and arrest in others.
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Date Issued: 1981
PURL: http://purl.flvc.org/fcla/dt/14069
Subject Headings: Offshore structures--Welding, Welded joints--Fatigue
Format: Document (PDF)

Title: FATIGUE CRACK DEVELOPMENT IN CATHODICALLY POLARIZED WELDED STEEL IN SEAWATER.
Creator: WEHLING, CHRISTOPHER MARK., Florida Atlantic University, Hartt, William H., College of Engineering and Computer Science, Department of Ocean and Mechanical Engineering
Abstract/Description: The fatigue crack growth behavior of welded ABS DH32 steel spec~mens cathodically polarized to -1.00 volt (Cu-CuS04) and subjected to bending fatigue of nominal stress + 69 MN/m^2 (+- 10 ksi) in seawater was investigated. Small non-propagating surface cracks with lengths up to 4.93 mm formed in the specimens. There were no s~gns of failure after 36 x 10^6 cycles when the experiment was terminated. Comparison of this test with similar freely corroding and -0.85 volt (Cu-CuS04) tests indicated...
Show moreThe fatigue crack growth behavior of welded ABS DH32 steel spec~mens cathodically polarized to -1.00 volt (Cu-CuS04) and subjected to bending fatigue of nominal stress + 69 MN/m^2 (+- 10 ksi) in seawater was investigated. Small non-propagating surface cracks with lengths up to 4.93 mm formed in the specimens. There were no s~gns of failure after 36 x 10^6 cycles when the experiment was terminated. Comparison of this test with similar freely corroding and -0.85 volt (Cu-CuS04) tests indicated that -1.00 volt (Cu-CuS04) cathodic protection is conducive to arrestment of small fatigue cracks. This suggests that modest cathodic over-protection of steel in seawater may beneficial.
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Date Issued: 1981
PURL: http://purl.flvc.org/fcla/dt/14091
Subject Headings: Steel--Fatigue
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: SIMULATED NORTH SEA SPECTRUM FATIGUE ON WELDED STEEL IN FLOWING SEA WATER.
Creator: Clark, A. M., Florida Atlantic University, Hartt, William H.
Abstract/Description: Reverse bend, uniform stress beam specimens of ABS DH-32 steel were subjected to fatigue cycles of randomly generated amplitude in a sea water environment to determine the effect of narrow band spectrum loading on cycles to failure. The loading spectrum was the C/12/20 spectrum, developed at the National Engineering Laboratory in Scotland to simulate the severe conditions of the North Sea. Some misinformation which has been published by NEL and other& regarding ~he C/12/20 spectrum is...
Show moreReverse bend, uniform stress beam specimens of ABS DH-32 steel were subjected to fatigue cycles of randomly generated amplitude in a sea water environment to determine the effect of narrow band spectrum loading on cycles to failure. The loading spectrum was the C/12/20 spectrum, developed at the National Engineering Laboratory in Scotland to simulate the severe conditions of the North Sea. Some misinformation which has been published by NEL and other& regarding ~he C/12/20 spectrum is addressed. A number ot means for presenting random amplitude cycles to failure data in the form of an SN plot are discussed. A means for taking into account fatigue test cycling rate in failure predictions is proposed, and the results of the freely corroding specimens of this investigation conform to the proposed technique. The random amplitude specimens exhibited reduced fatigue lives compared with similar specimens of an earlier constant amplitude investigation.
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Date Issued: 1983
PURL: http://purl.flvc.org/fcla/dt/14153
Subject Headings: Steel--Fatigue, Steel--Stress corrosion
Format: Document (PDF)

Title: SPECTRUM FATIGUE ON WELDED STRUCTURAL STEEL UNDER CORROSION AND CATHODIC PROTECTION CONDITIONS.
Creator: YANG, JOE-MING., Florida Atlantic University, Hartt, William H., College of Engineering and Computer Science, Department of Ocean and Mechanical Engineering
Abstract/Description: The object of this work was to investigate the fatigue performance of 25.4mm thick, butt welded ABS DH-32 steel plate under spectrum loading, which simulated the environmental conditions of the North Sea. Specimens were tested in sea water under different levels of cathodic protection. The results, including the previous freely corroding data, are discussed with regard to the effect of cyclic - frequency, loading history, weld profile and cathodic protection. This study indicated that load...
Show moreThe object of this work was to investigate the fatigue performance of 25.4mm thick, butt welded ABS DH-32 steel plate under spectrum loading, which simulated the environmental conditions of the North Sea. Specimens were tested in sea water under different levels of cathodic protection. The results, including the previous freely corroding data, are discussed with regard to the effect of cyclic - frequency, loading history, weld profile and cathodic protection. This study indicated that load interaction effects are negligible in the present experiments. However, frequency, weld geometry and cathodic protection significantly effect fatigue life.
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Date Issued: 1984
PURL: http://purl.flvc.org/fcla/dt/14207
Subject Headings: Steel, Structural--Fatigue, Steel, Structural--Testing
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: CORROSION OF STEEL REINFORCEMENT IN CONCRETE: THRESHOLD CHLORIDE ION CONCENTRATION FOR CORROSION IN TYPE I PORTLAND CEMENT CONCRETE.
Creator: FUNAHASHI, MIKI., Florida Atlantic University, Hartt, William H.
Abstract/Description: Initiation of corrosion of reinforcing steel in concrete is often caused by chlorides. Using a pressurized method for the purpose of accelerating penetration of sea water into concrete, the threshold chloride ion concentration for corrosion of reinforcing steel in Type I portland cement concrete has been studied in detail. The variables that have been investigated include water-cement ratio and steel surface preparation. When corrosion was detected by electrochemical potential measurement,...
Show moreInitiation of corrosion of reinforcing steel in concrete is often caused by chlorides. Using a pressurized method for the purpose of accelerating penetration of sea water into concrete, the threshold chloride ion concentration for corrosion of reinforcing steel in Type I portland cement concrete has been studied in detail. The variables that have been investigated include water-cement ratio and steel surface preparation. When corrosion was detected by electrochemical potential measurement, the test was terminated; and chloride ion concentration was evaluated. No correlation between threshold concentration and water-cement ratio was found. With regard to surface condition, the pre-rusted steel specimen showed a tendency to corrode at a lesser chloride ion concentration than for the other preparation techniques, which were sand blasting and pretreatment in a saturated calcium hydroxide solution. The results are presented and discussed within a perspective of established concrete and corrosion technologies.
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Date Issued: 1985
PURL: http://purl.flvc.org/fcla/dt/14264
Subject Headings: Steel--Corrosion, Reinforced concrete
Format: Document (PDF)

Title: STUDY OF THE WIDE-BAND SPECTRUM FATIGUE ON WELDED OFFSHORE STRUCTURES.
Creator: CHU, ZIN-HON., Florida Atlantic University, Hartt, William H.
Abstract/Description: In the present research butt welded ABS DH-32 steel specimens were fatigue tested under freely corroding and cathodic protection conditions by a time-series simulated wide-band spectra of a North Sea wave climate. Previous research pertaining to the probabilistic features of wave dynamics, wave force models, Markov-Chain sea state evolution and time-series simulation of wide-band spectra are addressed as a background review. The resulting freely corroding data are discussed on the basis of...
Show moreIn the present research butt welded ABS DH-32 steel specimens were fatigue tested under freely corroding and cathodic protection conditions by a time-series simulated wide-band spectra of a North Sea wave climate. Previous research pertaining to the probabilistic features of wave dynamics, wave force models, Markov-Chain sea state evolution and time-series simulation of wide-band spectra are addressed as a background review. The resulting freely corroding data are discussed on the basis of the SN plot which developed from the previous investigations at FAU. Calculation of the damage of failed specimens by employing the "Equivalent Narrow-Band Approach" resulted in excellent agreement with the linear damage summation assumption.
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Date Issued: 1985
PURL: http://purl.flvc.org/fcla/dt/14266
Subject Headings: Steel--Fatigue, Steel--Corrosion
Format: Document (PDF)

FAU Theses and Dissertations (80)	+ -
HBOI Faculty Contributions (1)	+ -
Florida Atlantic University Patents (1)	+ -

Steel--Corrosion (19)	+ -
Cathodic protection (15)	+ -
Steel--Fatigue (9)	+ -
Corrosion and anti-corrosives (8)	+ -
Reinforced concrete--Corrosion (8)	+ -

Chlorides (6)	+ -
Sea-water corrosion (6)	+ -
Seawater corrosion (6)	+ -
Offshore structures (4)	+ -
Pipelines--Cathodic protection (4)	+ -
Seawater (4)	+ -
Steel--Cathodic protection (4)	+ -
Underwater pipelines (4)	+ -
Aluminum--Corrosion (3)	+ -
Concrete--Corrosion (3)	+ -
Prestressed steel construction (3)	+ -
Reinforced concrete construction--Corrosion (3)	+ -
Reinforcing bars--Corrosion (3)	+ -
Steel, Structural--Fatigue (3)	+ -
Steel--Fracture (3)	+ -
Bridges--Florida (2)	+ -
Chlorides--Diffusion rate (2)	+ -
Composite reinforced concrete (2)	+ -
Concrete--Additives (2)	+ -
Concrete--Deterioration (2)	+ -
Marine steel (2)	+ -
Post-tensioned prestressed concrete construction (2)	+ -
Prestressed concrete--Corrosion (2)	+ -
Reinforced concrete (2)	+ -
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