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Corrosion Propagation of Reinforcing Steel Embedded in Binary and Ternary Concrete
Title
Corrosion Propagation of Reinforcing Steel Embedded in Binary and Ternary Concrete.
Creator
Hoque, Kazi Naimul, Presuel-Moreno, Francisco, Florida Atlantic University, Department of Ocean and Mechanical Engineering, College of Engineering and Computer Science
Abstract/Description
The Florida Department of Transportation (FDOT) has been using supplementary cementitious materials while constructing steel reinforced concrete marine bridge structures for over three decades. It has been found from previous studies that such additions in concrete mix makes the concrete more durable. This research was conducted to better understand the corrosion propagation stage of steel rebar embedded in high performance concrete exposed to high humidity environment. Reinforced concrete...
Show moreThe Florida Department of Transportation (FDOT) has been using supplementary cementitious materials while constructing steel reinforced concrete marine bridge structures for over three decades. It has been found from previous studies that such additions in concrete mix makes the concrete more durable. This research was conducted to better understand the corrosion propagation stage of steel rebar embedded in high performance concrete exposed to high humidity environment. Reinforced concrete samples that were made with binary mixes, and ternary mixes were considered. None of these concretes had any admixed chloride to start with. An accelerated chloride transport method was used to drive chloride ions into the concrete so that chlorides reached and exceed the chloride threshold at the rebar surface and hence the corrosion process initiated after a short period of time (within few days to few months). Once corrosion has initiated the corrosion propagation can be studied. Electrochemical measurements such as rebar potential measurements, Linear Polarization Resistance (LPR), Electrochemical Impedance Spectroscopy (EIS), and Galvanostatic Pulse (GP) measurements were taken at regular intervals (during and after the electro-migration process) to observe the corrosion propagation in each sample. During the propagation stage, reinforcement eventually reached negative potentials values (i.e., Ecorr≤ –0.200 Vsce) for all the samples. The corrected polarization resistance (Rc) was calculated by subtracting the concrete solution resistance from the apparent polarization resistance measured. The Rc values obtained from LPR and GP measurements were converted to corrosion current (as the corroding area is unknown), and these corrosion current values measured over time were used to obtain the calculated mass loss (using Faraday’s Law). A comparison was made of the calculated corrosion current obtained using the LPR and GP tests. A comparison of mass loss was also obtained from the values measured from LPR and GP tests. From the experimental results, it was observed that the corrosion current values were largely dependent on the length of solution reservoirs. For specimens cast with single rebar as well as three rebars, the most recent corrosion current values (measurements taken between July 2018 to October 2020) in general were larger for the rebars that are embedded in specimens prepared with SL mix, followed by specimens prepared with FA, T1, and T2 mixes respectively. The range of corrosion current values (most recent) were 0.8-33.8 μA for SL samples, 0.5-22.5 μA for FA samples, 0.8-14.8 μA for T1 samples, and 0.7-10.4 μA for T2 samples respectively. It was also found that the calculated mass loss values were larger for rebars that are embedded in specimens (single rebar and three rebars) prepared with SL mix, followed by specimens prepared with FA, T1, and T2 mixes respectively. The range of calculated mass loss values were 0.07-1.13 grams for SL samples, 0.06-0.62 grams for FA samples, 0.12-0.54 grams for T1 samples, and 0.06-0.40 grams for T2 samples respectively. A variety of corrosion related parameters (Ecorr, Rs, Rc, and Icorr) and calculated theoretical mass loss values observed, were due to the changing parameters such as concrete compositions, concrete cover thickness, rebar diameter, total ampere-hour applied, and reservoir size. The specimens showed no visual signs of corrosion such as cracks or corrosion products that reached the concrete surface. The actual size of the corroding sites was unknown as the specimens were not terminated for forensic analysis. The size of the corroding sites could affect how much corrosion products are required to crack the concrete. It is speculated that the corrosion products in liquid form penetrated the pore structure but did not build up enough to cause cracks. No cracks or corrosion bleed outs were observed within the monitored propagation period of approximately 1600 days.
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Date Issued
2020
PURL
http://purl.flvc.org/fau/fd/FA00013634
Subject Headings
Concrete, Concrete bridges--Corrosion, Carbon steel
Format
Document (PDF)
effects of substrate, surface finish, flow rate and exposure duration on calcareous deposits
Title
The effects of substrate, surface finish, flow rate and exposure duration on calcareous deposits.
Creator
Mantel, Katherine Elizabeth., Florida Atlantic University, Hartt, William H., College of Engineering and Computer Science, Department of Ocean and Mechanical Engineering
Abstract/Description
The effect of substrate finish and composition, flow rate and exposure duration on the composition, morphology and protective properties of calcareous deposits formed during cathodic polarization of several steels in seawater has been investigated. The current density behaviour of the scale formation in conjunction with morphology and composition characteristics indicated that the substrate finish and composition did not influence the nucleation or growth of the deposit. The results strongly...
Show moreThe effect of substrate finish and composition, flow rate and exposure duration on the composition, morphology and protective properties of calcareous deposits formed during cathodic polarization of several steels in seawater has been investigated. The current density behaviour of the scale formation in conjunction with morphology and composition characteristics indicated that the substrate finish and composition did not influence the nucleation or growth of the deposit. The results strongly suggest a relationship between electrolyte velocity, current density behaviour and morphology. With increased flow and consequent higher current density requirements, results indicated a low nucleation rate of CaCO3. The current density behaviour and composition of the calcareous deposit revealed a growth progression of a Mg rich film formed in the first few minutes, followed by an increasingly uniform surface coverage by CaCO3 in the form of aragonite.
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Date Issued
1989
PURL
http://purl.flvc.org/fcla/dt/14575
Subject Headings
Steel--Cathodic protection, Calcium carbonate
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)
CORROSION MONITORING AND ANALYSIS OF REINFORCED CONCRETE: CORROSION RESISTANT ALLOYS AFTER LONG TERM EXPOSURE TO CHLORIDES
Title
CORROSION MONITORING AND ANALYSIS OF REINFORCED CONCRETE: CORROSION RESISTANT ALLOYS AFTER LONG TERM EXPOSURE TO CHLORIDES.
Creator
Taylor, Redmayne, Presuel-Moreno, Francisco, Florida Atlantic University, Department of Ocean and Mechanical Engineering, College of Engineering and Computer Science
Abstract/Description
Reinforced concrete (RC) is the building block of modern architecture and industry. The failure of which is costly and dangerous. Typically made with carbon steel rebars, corrosion resistant alloys provide an alternative method of delaying failure. Stainless steels, while more expensive than carbon steels, provide excellent corrosion resistance, but less is known about the long term monitoring of corrosion activity for stainless steel than for carbon steel. This study looks at samples...
Show moreReinforced concrete (RC) is the building block of modern architecture and industry. The failure of which is costly and dangerous. Typically made with carbon steel rebars, corrosion resistant alloys provide an alternative method of delaying failure. Stainless steels, while more expensive than carbon steels, provide excellent corrosion resistance, but less is known about the long term monitoring of corrosion activity for stainless steel than for carbon steel. This study looks at samples prepared between 2005 and 2009 using 304SS, 316SS, and 2304SS rebars, as well as SMI and Stelax stainless steel clad carbon steel reinforcements embedded in three different concrete mixes. These selected samples are split into two exposure environments, inside humidity chambers within the laboratory and outdoor exposure. Measurements reported here were made monthly over the course of 250 plus days using the Galvanostatic Pulse method, Electrochemical Impedance Spectroscopy, and a Gecor 8 device. These methods were used to determine corrosion current, isolated corrosion current density, and solution resistance. Corrosion current density values calculated from measurements by the Galvanostatic Pulse and Electrochemical Impedance Spectroscopy method are too small to indicate corrosion, based on value ranges provided by Andrade. However, Gecor 8 corrosion current density values indicate low levels or moderate levels of corrosion for all samples compared to the Andrade’s value ranges. The area used by the Gecor is unknown, so it’s possible this is driving up the measured values.
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Date Issued
2023
PURL
http://purl.flvc.org/fau/fd/FA00014258
Subject Headings
Reinforced concrete, Corrosion resistant alloys, Carbon steel, Corrosion
Format
Document (PDF)
STUDY OF THE EFFECT OF FLOW PARAMETERS ON THE CATHODIC PROTECTION OF A STEEL PLATE IN NATURAL SEAWATER
Title
A STUDY OF THE EFFECT OF FLOW PARAMETERS ON THE CATHODIC PROTECTION OF A STEEL PLATE IN NATURAL SEAWATER.
Creator
MCCABE, KEVIN MICHAEL., Florida Atlantic University, Smith, Samuel W., College of Engineering and Computer Science, Department of Ocean and Mechanical Engineering
Abstract/Description
The influence of hydrodynamic parameters and cathodic polarization on the formation of calcareous deposits on a steel plate in flowing seawater is investigated. Current density variations on the plate are determined for a combination of applied potentials and seawater velocities. Equations are developed to relate the cathodic current density distribution to variations in hydrodynamic and diffusional boundary layer thickness along the plate for laminar and turbulent flow regimes. A comparison...
Show moreThe influence of hydrodynamic parameters and cathodic polarization on the formation of calcareous deposits on a steel plate in flowing seawater is investigated. Current density variations on the plate are determined for a combination of applied potentials and seawater velocities. Equations are developed to relate the cathodic current density distribution to variations in hydrodynamic and diffusional boundary layer thickness along the plate for laminar and turbulent flow regimes. A comparison of experimental current densities on a bare plate to that predicted by theory is examined. Effects of flow on the formation and properties of calcareous deposits are discussed in light of recent developments in marine cathodic protection.
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Date Issued
1984
PURL
http://purl.flvc.org/fcla/dt/14192
Subject Headings
Plates, Iron and steel--Cathodic protection, Carbon steel--Corrosion, Plates, Iron and steel--Fluid dynamics, Cathodic protection
Format
Document (PDF)
Feasibility of using carbon fiber reinforced plastic tendons in prestressed concrete Double-Tee bridge system
Title
Feasibility of using carbon fiber reinforced plastic tendons in prestressed concrete Double-Tee bridge system.
Creator
Zhuang, Ming., Florida Atlantic University, Arockiasamy, Madasamy, College of Engineering and Computer Science, Department of Ocean and Mechanical Engineering
Abstract/Description
One of the major problems the construction industry faces today is corrosion of reinforcing and prestressing steel, which significantly affects the durability of concrete structures. Fiber reinforced plastics (FRPs) are highly regarded as prospective replacement for steel in prestressed concrete structures under corrosive environment. This investigation was conducted to establish the feasibility of using Carbon Fiber Composite (CFC) cables as reinforcing/prestressing elements in concrete...
Show moreOne of the major problems the construction industry faces today is corrosion of reinforcing and prestressing steel, which significantly affects the durability of concrete structures. Fiber reinforced plastics (FRPs) are highly regarded as prospective replacement for steel in prestressed concrete structures under corrosive environment. This investigation was conducted to establish the feasibility of using Carbon Fiber Composite (CFC) cables as reinforcing/prestressing elements in concrete bridge structures. Besides investigating durability of CFC cables and pretensioned concrete beams with CFC cables in adverse environments (alkali and seawater), flexure and shear tests were performed on single Double-Tee beams, together with service load behavior, fatigue strength and ultimate load capacity tests on a half scale model Double-Tee girder bridge system prestressed with CFC cables. Exposure to seawater and alkali environments has no adverse effect on the strength of the CFRP tendons as well as the pretensioned beams with CFRP. Based on the flexural strength tests on Double-Tee beams, the bond between CFRP tendons and concrete is satisfactory. The Double-Tee bridge system exhibited good fatigue resistance and adequate ductility under ultimate load conditions. The ultimate load capacity of the bridge is approximately three times the service load corresponding to two HS20-44 trucks and equals 2.4 times the first crack load. Finite element analyses were carried out to predict elastic deformations and collapse load of the Double-Tee bridge prestressed with CFC cables. Feasibility of using CFC cables in bridge structures is assessed based on the experimental and analytical parameters such as deflections, strains, crack distributions and crack widths.
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Date Issued
1996
PURL
http://purl.flvc.org/fcla/dt/12465
Subject Headings
Carbon fibers, Composite construction, Fiber reinforced plastics, Bridges, Iron and steel, Reinforced concrete construction, Prestressed concrete construction
Format
Document (PDF)