Current Search:  Department of Ocean and Mechanical Engineering (x) » Reinforced concrete--Corrosion (x)

View All Items

  • CSV Spreadsheet
(1 - 9 of 9)
ACOUSTIC EMISSION ASSOCIATED WITH EMBEDDED METAL CORROSION IN A CONCRETE SLAB
Title
ACOUSTIC EMISSION ASSOCIATED WITH EMBEDDED METAL CORROSION IN A CONCRETE SLAB.
Creator
MARSHALL, RICHARD MELBOURNE., Florida Atlantic University, Dunn, Stanley E., College of Engineering and Computer Science, Department of Ocean and Mechanical Engineering
Abstract/Description
Measured values of attenuation with distance, amplitude distribution, and propagation velocity of acoustic emissions associated with embedded metcil corrosion induced cracking in a concrete slab are presented. An extensive review of acoustic emission signal processing techniques and theoretical background material is also included. The study points out how attenuation and propagation velocity of the acoustic emission signal affects various signal processing techniques and verifies an...
Show moreMeasured values of attenuation with distance, amplitude distribution, and propagation velocity of acoustic emissions associated with embedded metcil corrosion induced cracking in a concrete slab are presented. An extensive review of acoustic emission signal processing techniques and theoretical background material is also included. The study points out how attenuation and propagation velocity of the acoustic emission signal affects various signal processing techniques and verifies an amplitude distribution spreading rrodel. The need for further defirlition of attentuation values caused by fluid loading of the concrete surface is also discussed.
Show less
Date Issued
1982
PURL
http://purl.flvc.org/fcla/dt/14129
Subject Headings
Reinforced concrete--Corrosion, Acoustic emission testing
Format
Document (PDF)
ACOUSTIC EMISSIONS TESTING AS A NONDESTRUCTIVE MONITOR OF CONCRETE CRACKING DUE TO REINFORCING BAR CORROSION
Title
ACOUSTIC EMISSIONS TESTING AS A NONDESTRUCTIVE MONITOR OF CONCRETE CRACKING DUE TO REINFORCING BAR CORROSION.
Creator
YOUNG, JAMES DANIEL., Florida Atlantic University, Dunn, Stanley E., College of Engineering and Computer Science, Department of Ocean and Mechanical Engineering
Abstract/Description
Steel reinforced concrete specimens of loaded and unloaded configuration were placed in contact with seawater in a state of accelerated corrosion. They were simultaneously monitored for acoustic emission and the results were analyzed in an evaluation of the use of acoustic emission as a nondestructive monitor of corrosion induced cracking. It was shown that, in a laboratory environment, counts and amplitude information are sensitive indicators of the levels of cracking within the concrete...
Show moreSteel reinforced concrete specimens of loaded and unloaded configuration were placed in contact with seawater in a state of accelerated corrosion. They were simultaneously monitored for acoustic emission and the results were analyzed in an evaluation of the use of acoustic emission as a nondestructive monitor of corrosion induced cracking. It was shown that, in a laboratory environment, counts and amplitude information are sensitive indicators of the levels of cracking within the concrete specimen; and thereby the degree of corrosion damage may be inferred. Analytical models applicable to the representation of acoustic emission amplitude distribution are discussed also.
Show less
Date Issued
1982
PURL
http://purl.flvc.org/fcla/dt/14141
Subject Headings
Reinforced concrete--Cracking, Reinforced concrete--Corrosion, Acoustic emission testing
Format
Document (PDF)
Characterization of electrochemical properties of arc-sprayed zinc and zinc-aluminum alloy coatings for cathodic protection of reinforced concrete structures
Title
Characterization of electrochemical properties of arc-sprayed zinc and zinc-aluminum alloy coatings for cathodic protection of reinforced concrete structures.
Creator
Sigonney, Yann Manuel., Florida Atlantic University, Hartt, William H., College of Engineering and Computer Science, Department of Ocean and Mechanical Engineering
Abstract/Description
The present research focused on the behavior of arc sprayed zinc and zinc-aluminum coatings on concrete specimens exposed to specific relative humidity environments (100, 85, 60 and 25% RH) and with specific chloride contents (0.0, 3.0, 5.9 and 11.8 kg/m^3). All specimens experienced a decline in current output with time. Anode wastage and formation of oxidation products were mainly responsible for this lack of protection in 100 and 85% RH, whereas for 60 and 25% RH, drying of the concrete...
Show moreThe present research focused on the behavior of arc sprayed zinc and zinc-aluminum coatings on concrete specimens exposed to specific relative humidity environments (100, 85, 60 and 25% RH) and with specific chloride contents (0.0, 3.0, 5.9 and 11.8 kg/m^3). All specimens experienced a decline in current output with time. Anode wastage and formation of oxidation products were mainly responsible for this lack of protection in 100 and 85% RH, whereas for 60 and 25% RH, drying of the concrete and long-term polarization of the anode were the key factors. Validity of the DC measurements was verified with slope parameter analysis on selected specimens. In addition, Electrochemical Impedance Spectroscopy was performed on the galvanic anode and an equivalent circuit model was obtained for the zinc-concrete interface.
Show less
Date Issued
1999
PURL
http://purl.flvc.org/fcla/dt/15665
Subject Headings
Reinforced concrete--Corrosion, Cathodic protection, Zinc coating
Format
Document (PDF)
Computer simulation of corrosion fatigue of reinforced concrete beams in marine environment
Title
Computer simulation of corrosion fatigue of reinforced concrete beams in marine environment.
Creator
Ranade, Sonali S., Florida Atlantic University, Reddy, Dronnadula V., College of Engineering and Computer Science, Department of Ocean and Mechanical Engineering
Abstract/Description
The effect of corrosion on the fatigue life of reinforced concrete beams is studied. Two analytical models are developed to study the chloride diffusion in concrete and the percent reduction in fatigue lives in seawater as compared to air. An initial stress equivalent to the tensile strength of concrete is induced in the rebar to simulate the corrosive nature of marine environment. The analytical values are compared with the available experimental data.
Date Issued
1993
PURL
http://purl.flvc.org/fcla/dt/14914
Subject Headings
Concrete beams--Fatigue--Computer simulation, Reinforced concrete--Corrosion, Sea water corrosion
Format
Document (PDF)
CRACKING OF CONCRETE DUE TO CORROSION OF VARIOUS EMBEDDED METALS
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.
Show less
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)
DETECTION OF DETERIORATION OF REINFORCED CONCRETE BY ACOUSTIC EMISSION TECHNIQUES
Title
DETECTION OF DETERIORATION OF REINFORCED CONCRETE BY ACOUSTIC EMISSION TECHNIQUES.
Creator
WENG, MING-YUAN., Florida Atlantic University, Dunn, Stanley E., College of Engineering and Computer Science, Department of Ocean and Mechanical Engineering
Abstract/Description
In this investigation acoustic emission techniques were employed to detect deterioration of reinforced concrete. As a result of various laboratory tests, acoustic emission activity was found to be due to development of cracking only. Acoustic emission techniques were able to locate cracks in a specimen by linear location. Various acoustic emission parameters such as amplitude, signal shape and frequency were also analyzed and discussed. It was concluded that acoustic emission techniques...
Show moreIn this investigation acoustic emission techniques were employed to detect deterioration of reinforced concrete. As a result of various laboratory tests, acoustic emission activity was found to be due to development of cracking only. Acoustic emission techniques were able to locate cracks in a specimen by linear location. Various acoustic emission parameters such as amplitude, signal shape and frequency were also analyzed and discussed. It was concluded that acoustic emission techniques provided a feasible method for detection of deterioration and cracking of steel reinforced structures in laboratory studies as well as in a field environment.
Show less
Date Issued
1980
PURL
http://purl.flvc.org/fcla/dt/14042
Subject Headings
Acoustic emission testing, Reinforced concrete--Corrosion
Format
Document (PDF)
Influences of chlorides, pH and surface films on the corrosion of reinforcing steel in alkaline solutions
Title
Influences of chlorides, pH and surface films on the corrosion of reinforcing steel in alkaline solutions.
Creator
Sundaresan, Raman., Florida Atlantic University, Hartt, William H., College of Engineering and Computer Science, Department of Ocean and Mechanical Engineering
Abstract/Description
The objective of this study was to determine the influences of chlorides, pH and surface films on the corrosion of reinforcing steel in alkaline solutions. Anodic and linear polarization experiments were conducted on 1018 steel specimens exposed to these environments. The results indicate that there is a threshold amount of [Cl-] beyond which passivity is compromised. The i-passive in the electrolyte of pH 12.24 was approximately 0.01 of that in the electrolyte of pH 10.13. At least a one day...
Show moreThe objective of this study was to determine the influences of chlorides, pH and surface films on the corrosion of reinforcing steel in alkaline solutions. Anodic and linear polarization experiments were conducted on 1018 steel specimens exposed to these environments. The results indicate that there is a threshold amount of [Cl-] beyond which passivity is compromised. The i-passive in the electrolyte of pH 12.24 was approximately 0.01 of that in the electrolyte of pH 10.13. At least a one day period was necessary for the effect of the excess crystals of Ca(OH)2 to be felt. Corrosion rates of specimen with a Ca(OH)2 surface film were lower than without this film. [Cl-] /[OH-] in the range 2.5 to 3.5 appeared to be the threshold for breakdown of passivity.
Show less
Date Issued
1989
PURL
http://purl.flvc.org/fcla/dt/14520
Subject Headings
Reinforced concrete--Corrosion, Steel--Corrosion, Corrosion and anti-corrosives
Format
Document (PDF)
Performance of anodes in cathodic protection of reinforcing steel in concrete
Title
Performance of anodes in cathodic protection of reinforcing steel in concrete.
Creator
Venugopalan, Sivaraman., Florida Atlantic University, Hartt, William H., College of Engineering and Computer Science, Department of Ocean and Mechanical Engineering
Abstract/Description
Experiments were conducted on a simulated reinforced concrete bridge deck to test different anodes as part of a cathodic protection system. Both carbon based and titanium based anodes were tested. All the anodes were driven at predetermined current densities. Current off polarized potentials of steel and anode were monitored over six months. After this period, cores were extracted from slabs containing a part of anode and steel and then broken at the anode-concrete and steel-concrete...
Show moreExperiments were conducted on a simulated reinforced concrete bridge deck to test different anodes as part of a cathodic protection system. Both carbon based and titanium based anodes were tested. All the anodes were driven at predetermined current densities. Current off polarized potentials of steel and anode were monitored over six months. After this period, cores were extracted from slabs containing a part of anode and steel and then broken at the anode-concrete and steel-concrete interface to measure the pH at these interfaces. Differences in the pH values at the anode-concrete interface were compared to determine the performance of the different anodes. Carbon based anodes operated at a higher potential and produced anode corrosion products of lower pH when compared to titanium based anodes.
Show less
Date Issued
1990
PURL
http://purl.flvc.org/fcla/dt/14658
Subject Headings
Reinforcing bars--Cathodic protection, Reinforced concrete--Corrosion
Format
Document (PDF)
SERVICEABILITY OF REINFORCED CONCRETE BEAMS SUBJECTED TO ACCELERATED CORROSION (ACOUSTIC EMISSION, DAMAGE, REMAINING STRENGTH/LIFE, TESTING)
Title
SERVICEABILITY OF REINFORCED CONCRETE BEAMS SUBJECTED TO ACCELERATED CORROSION (ACOUSTIC EMISSION, DAMAGE, REMAINING STRENGTH/LIFE, TESTING).
Creator
TITUS, REJI NINAN K., Florida Atlantic University, Reddy, Dronnadula V., College of Engineering and Computer Science, Department of Ocean and Mechanical Engineering
Abstract/Description
Steel reinforced concrete beams were placed in contact with seawater in a state of accelerated corrosion, for varying periods of time. Some of them were simultaneously monitored for acoustic emission and the results were analyzed to evaluate the effectiveness of acoustic emission as a non-destructive monitor of corrosion induced damage. It was shown that, in a laboratory environment, counts are good indicators of the extent of corrosion damage. A review of acoustic emission monitoring...
Show moreSteel reinforced concrete beams were placed in contact with seawater in a state of accelerated corrosion, for varying periods of time. Some of them were simultaneously monitored for acoustic emission and the results were analyzed to evaluate the effectiveness of acoustic emission as a non-destructive monitor of corrosion induced damage. It was shown that, in a laboratory environment, counts are good indicators of the extent of corrosion damage. A review of acoustic emission monitoring techniques and theoretical background is included. The concrete beams were tested for flexural strength after being corroded. Reduction in rebar section was found to have a very good correlation with da mage. An attempt was made to predict remaining life of the beams based on data obtained from the tests.
Show less
Date Issued
1986
PURL
http://purl.flvc.org/fcla/dt/14310
Subject Headings
Reinforced concrete--Corrosion
Format
Document (PDF)