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Characterization of environmental cracking of cathodically polarized prestressing steel in a simulated concrete environment
Title
Characterization of environmental cracking of cathodically polarized prestressing steel in a simulated concrete environment.
Creator
Narayanan, P. K., 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 environmental cracking tendency of prestressing steel tendons under cathodically polarized conditions, a series of slow strain rate tests were conducted using smooth and notched specimens in simulated concrete porewater environments. Applied potential was varied from -0.500 V to -1.500 V(SCE) at intervals of 0.200 V, and the pH range was 8.0 to 12.5. Based on the test results presented in terms of time-to-failure, reduction in crosssectional area and load at...
Show moreIn order to investigate the environmental cracking tendency of prestressing steel tendons under cathodically polarized conditions, a series of slow strain rate tests were conducted using smooth and notched specimens in simulated concrete porewater environments. Applied potential was varied from -0.500 V to -1.500 V(SCE) at intervals of 0.200 V, and the pH range was 8.0 to 12.5. Based on the test results presented in terms of time-to-failure, reduction in crosssectional area and load at failure, potential regimes for susceptibility to hydrogen embrittlement in saturated Ca(OH)2 solution were identified. SEM analyses performed for both notched and smooth specimens tested at -0.700 V and -1.300 V in saturated Ca(OH)2 solution showed that different fracture mechanisms operate at these two potentials. The cracking processes have been explained based on the test results and SEM analyses. Based upon the data obtained, the steel showed higher resistance to environmental cracking at pH 9.8 and 8.0 than for 12.5. The applicability of the results to cathodic protection of prestressed steel in concrete is discussed.
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Date Issued
1988
PURL
http://purl.flvc.org/fcla/dt/14472
Subject Headings
Steel, High strength--Brittleness
Format
Document (PDF)
Environmental cracking of prestressing steel in calcium-hydroxide solutions
Title
Environmental cracking of prestressing steel in calcium-hydroxide solutions.
Creator
Kumria, Chetan Chand., Florida Atlantic University, Hartt, William H., College of Engineering and Computer Science, Department of Ocean and Mechanical Engineering
Abstract/Description
Failure of prestressed steel tendon in concrete due to corrosion or environmental cracking (or both) has become a major technological concern because of increased utilization of this form of construction in corrosive exposure such as coastal bridge deck structures. At the same time cathodic protection has evolved as the most practical means for arresting corrosion of reinforcing steel in existing structures. This technology also applies to pretensioned tendons. However, concerns have been...
Show moreFailure of prestressed steel tendon in concrete due to corrosion or environmental cracking (or both) has become a major technological concern because of increased utilization of this form of construction in corrosive exposure such as coastal bridge deck structures. At the same time cathodic protection has evolved as the most practical means for arresting corrosion of reinforcing steel in existing structures. This technology also applies to pretensioned tendons. However, concerns have been raised that cathodic protection might cause embrittlement, since yield stress of these materials is relatively high. For the purpose of analyzing this embrittlement tendency a series of constant load and slow strain rate experiments were performed and the data evaluated. Influence of potential, chloride concentration, pH and precharging on the cracking susceptibility have been evaluated. The cracking process has been explained based on test results and SEM analysis.
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Date Issued
1989
PURL
http://purl.flvc.org/fcla/dt/14531
Subject Headings
Steel, High strength--Brittleness
Format
Document (PDF)
Fatigue of high strength steels in sea water
Title
Fatigue of high strength steels in sea water.
Creator
Sablok, Anil Kumar., Florida Atlantic University, Hartt, William H., College of Engineering and Computer Science, Department of Ocean and Mechanical Engineering
Abstract/Description
Fatigue response of selected high strength steels in seawater was investigated under conditions relevant to tension leg platform tendon applications. This involved both freely corroding and cathodically protected, displacement controlled experiments upon constant taper, bending specimens which were either notched or welded, ground and post weld heat treated. High stress range freely corroding results indicated enhanced life compared to structural steel, whereas at low stress range the...
Show moreFatigue response of selected high strength steels in seawater was investigated under conditions relevant to tension leg platform tendon applications. This involved both freely corroding and cathodically protected, displacement controlled experiments upon constant taper, bending specimens which were either notched or welded, ground and post weld heat treated. High stress range freely corroding results indicated enhanced life compared to structural steel, whereas at low stress range the opposite was true. Corrections made to the high strength steel and structural steel data to correspond to similar test conditions revealed no benefit of enhanced material strength on corrosion fatigue life. Fatigue life for all cathodically protected specimens exceeded that for the freely corroding ones, and with one exception testing was terminated prior to failure. The single cathodically protected specimen failure involved a stress range approximately one-third the value for other specimens which were run-outs. This suggests that an environmental cracking process may operate precipitously at relatively low stress amplitudes (alternately, high R values). Fatigue life for freely corroding notched specimens was less than for grounded PWHT specimens, the difference increasing with decreasing amplitude.
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Date Issued
1988
PURL
http://purl.flvc.org/fcla/dt/14463
Subject Headings
Steel--Fatigue, Steel, High strength
Format
Document (PDF)
CORROSION FATIGUE CRACK INITIATION BEHAVIOR OF SEVERAL HIGH STRENGTH STEELS IN SEAWATER (POTENTIAL, CATHODIC, POLARIZATION)
Title
CORROSION FATIGUE CRACK INITIATION BEHAVIOR OF SEVERAL HIGH STRENGTH STEELS IN SEAWATER (POTENTIAL, CATHODIC, POLARIZATION).
Creator
SLOAN, FORREST EUGENE., Florida Atlantic University, Hartt, William H., College of Engineering and Computer Science, Department of Ocean and Mechanical Engineering
Abstract/Description
'J 'ht' c· f feet of seawater ,_tnd potential on the fatigue crack initiation hehavior of several microalloyed and thermomPrhanically processed steels has been investigated. Five steels with yield strength in t~e range 500 to 750 MPa (73 to 108 ksi) were selected which included a range of processing histories from conventional quenching and tempering to precipitation hardening and direct quenching. These steels were chosen because of their potential utility as materials of construction for...
Show more'J 'ht' c· f feet of seawater ,_tnd potential on the fatigue crack initiation hehavior of several microalloyed and thermomPrhanically processed steels has been investigated. Five steels with yield strength in t~e range 500 to 750 MPa (73 to 108 ksi) were selected which included a range of processing histories from conventional quenching and tempering to precipitation hardening and direct quenching. These steels were chosen because of their potential utility as materials of construction for deep water compliant platform hull and riser systems. Blunt notch compact tension specimens were exposed to natural flowing seawater under constant load ampli tnrlc. conditions at both freely corroding and cathodically protected potentials. Cycles to crack initiation were characterized by cyclic stress intensity range normalized relative to the square root of notch radius. Test data are presented and compared with data from other tests and steels using appropriate stress analysis methods.
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Date Issued
1986
PURL
http://purl.flvc.org/fcla/dt/14285
Subject Headings
Steel, High strength--Fatigue--Testing, Sea-water corrosion
Format
Document (PDF)
THE IMPACT CORROSION HAS ON THE DEGRADATION OF MECHANICAL PROPERTIES OF CARBON STEEL REBARS IN HIGH PERFORMANCE CONCRETE
Title
THE IMPACT CORROSION HAS ON THE DEGRADATION OF MECHANICAL PROPERTIES OF CARBON STEEL REBARS IN HIGH PERFORMANCE CONCRETE.
Creator
Rosa-Pagan, Angel R., Presuel-Moreno, Francisco, Florida Atlantic University, Department of Ocean and Mechanical Engineering, College of Engineering and Computer Science
Abstract/Description
A significant amount of reinforced concrete structures in the USA are reaching the design life span of 50 years. Degradation of these infrastructure due to corrosion presents an economical, safety and quality of life challenge for our society. Being able to study and determine the conditions of our infrastructure, perform maintenance before failure and predict failure before occurrence has become critical for our society and our way of life. This study was performed to add to existing...
Show moreA significant amount of reinforced concrete structures in the USA are reaching the design life span of 50 years. Degradation of these infrastructure due to corrosion presents an economical, safety and quality of life challenge for our society. Being able to study and determine the conditions of our infrastructure, perform maintenance before failure and predict failure before occurrence has become critical for our society and our way of life. This study was performed to add to existing research in the understanding of the relationships between the corrosion current of the embedded carbon steel rebars in reinforced concrete, rebar mass loss due to corrosion and the degradation of the mechanical properties of the carbon steel embedded in high performance concrete structures. The study also aimed to study the influence of different independent variables such as the chloride solution reservoir size and the concrete composition of the prepared specimens for the study. Specimens for the study were prepared by embedding three carbon steel size #4 rebars in blocks of high performing concrete with different admixture to enhance their performance against corrosion. To initiate corrosion specimens were exposed to accelerated chloride transport method (electromigration). To accelerate corrosion some samples were selected for anodic polarization and additional electromigration. After corrosion initiation, the rebars Open Circuit Potential (OCP) and corrosion current (Icorr) were periodically measured using a galvanostat device from April 2017 to August 2021. The OCP average values showed that all the rebars considered in this study were in active corrosion. Faraday’s law was used to determine the rebar calculated mass loss from the measured corrosion current and the elapse time between measurements. The rebar mass loss was in turn used to model the loss of the physical properties of the rebar (yield strength, ultimate strength, and ultimate strain) using (Vanama & Ramakrishnan, 2020) model. Analysis of these parameters results showed a direct relationship between the measured corrosion current and the calculated mass loss of the corroding rebar. The study also showed a direct relationship between the calculated mass loss of the corroding rebar and the degradation of the physical properties of the rebar.
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Date Issued
2021
PURL
http://purl.flvc.org/fau/fd/FA00013843
Subject Headings
Corrosion, Reinforced concrete--Deterioration, Carbon steel, High strength concrete
Format
Document (PDF)