Engineering Commons^™

Prediction Of Corrosion-Induced Crack Width Of Corroded Reinforced Concrete Structures, Jin Xia, Wei-Liang Jin

International Conference on Durability of Concrete Structures

This paper presents an experimental investigation on the crack width induced by the corrosion of reinforcing steel bars in concrete. Reinforcing steel bars with different diameters were corroded using an accelerated test in three types of concrete members, including 24 beams with corroded stirrup and 20 beams with corroded longitudinal reinforcing steel bars. The corrosion patterns and rusts characteristics of the corroded steel bars were examined and compared with those observed in real RC structures. According to the experimental result, the corrosioninduced crack width were analyzed and showed a linear relationship with the corrosion loss of reinforcing steel bar. Finally, …

Feasibility Of Application Of Cathodic Prevention To Cracked Reinforced Concrete In Marine Service, Kevin Williams

USF Tampa Graduate Theses and Dissertations

Corrosion can take place as chloride ions accumulate above a critical concentration (CT) at the surface of a reinforcing bar inside concrete in marine service. The initiation of corrosion can be delayed by polarizing the steel cathodically, which is known to increase the value of CT. That effect is the basis of the cathodic prevention (CPrev) method to control corrosion of reinforcing steel in concrete. However, concrete cracks are a common occurrence and at cracks, the buildup of chloride ions is accelerated to the extent that CPrev may be less effective. The findings from an ongoing investigation to determine the …

Friction Bit Joining Of Dissimilar Combinations Of Advanced High-Strength Steel And Aluminum Alloys, Lile P. Squires

Theses and Dissertations

Friction bit joining (FBJ) is a new method that enables lightweight metal to be joined to advanced high-strength steels. Weight reduction through the use of advanced high-strength materials is necessary in the automotive industry, as well as other markets, where weight savings are increasingly emphasized in pursuit of fuel efficiency. The purpose of this research is twofold: (1) to understand the influence that process parameters such as bit design, material type and machine commands have on the consistency and strength of friction bit joints in dissimilar metal alloys; and (2) to pioneer machine and bit configurations that would aid commercial, …

Electrochemical-Mechanistic Model For Concrete Cover Cracking Due To Corrosion Initiated By Chloride Diffusion, Goli Nossoni, Ronald S. Harichandran

Civil Engineering Faculty Publications

A holistic electrochemical-mechanistic model of the corrosion of steel reinforcing bars inside concrete that accounts for the diffusion of oxygen and moisture into the concrete and rust layers, the densification of rust due to confinement, the flow of rust into the concrete pores, the development of internal pressure due to rust buildup, and cracking of the concrete cover is presented. The relationship between the corrosion current and the pressure buildup due to the corrosion products for different concrete cover thicknesses and concrete quality was calibrated through experiments using an accelerated corrosion test with an applied current. Results from finite-element analysis …

Flexural Behavior Of Reinforced Concrete T-Beams Strengthened With Nsm Composite System Under Accelerated Corrosion., Anes Bouchair

Theses

This research work aims at evaluating the effects of corrosion on flexural response of simply supported reinforced concrete (RC) T-Beams strengthened with near-surface-mounted carbon fiber-reinforced polymer (NSM-CFRP) strips. The research comprised experimental testing and analytical modelling. Test parameters included concrete grade, amount of NSM-CFRP strips, presence of U-wraps along the beam span, and time of corrosion exposure. A total of eighteen reinforced concrete beams with a T-shaped cross section were tested. Fourteen beams were strengthened in flexure and four beams were not strengthened to act as benchmarks. The strengthening regime included installation of either two or four NSM-CFRP strips into …

Influence Of Surface Modification On Corrosion And Biocompatibility Of Titanium Alloys, Zia Ur Rahman

Theses and Dissertations - UTB/UTPA

Titanium alloys enhance the quality and longevity of human life by replacing or treating various parts of the body. However, the aggressive body fluids lead to corrosion and metal ions dissolution. These ions leach to the adjacent tissues and causes adverse reactions. Surface modifications improve corrosion resistance and biological activity. In this investigation, electropolishing, magnetoelectropolishing, titanium coating and hydroxyapatite coating were carried out on commercially pure titanium (CPTi), Ti6Al4V and Ti6Al4V-ELI (Extra Low Interstitials). These surface modifications are known to affect surface chemistry, morphology, wettability, corrosion resistance and biocompatibility of these materials. In vitro cyclic potentiodynamic polarization tests were conducted …

Corrosion Assessment And Enhanced Biocompatibility Analysis Of Biodegradable Magnesium-Based Alloys, Luis Enrique Pompa

Theses and Dissertations - UTB/UTPA

Magnesium alloys have raised immense interest to many researchers because of its evolution as a new third generation material. Due to their biocompatibility, density, and mechanical properties, magnesium alloys are frequently reported as prospective biodegradable implant materials. Moreover, magnesium based alloys experience a natural phenomena to biodegrade in aqueous solutions due to its corrosive activity, which is excellent for orthopedic and cardiovascular applications. However, major concerns with such alloys are fast and non-uniform corrosion degradation. Controlling the degradation rate in the physiological environment determines the success of an implant. In this investigation, three grades of magnesium alloys: AZ31B, AZ91E and …

In Vitro Immersion Behavior Of Cold Sprayed Hydroxyapatite/Titanium Composite Coatings, Lin Lu, Xuan Joe Zhou, Pravansu Mohanty

Electrical & Computer Engineering Publications

In previous study, dense and homogenous 20wt% HAP/Ti composite coatings were successfully deposited on Ti substrates by cold gas dynamic spray technique. The results revealed that the phase composition of the HAP in the deposit is identical to that of the precursor powder and the bonding strength of the deposit is comparable/better to that of the plasma sprayed HAP. A relatively higher corrosion current of HAP/Ti composite than that of pure Ti coating in simulated body fluid indicates a good bioactivity for composite coating. In the present study, in vitro immersion test is carried out for various period of time …

In Situ Detection On Electrochemical Chloride Removal Of Reinforcement In Concrete By Combined Ph/Cl- Probes, Jing-Jing Wang, Shi-Gang Dong, Xiao-Juan Zhang, Hong-Wei Lv, Yun-Chang Wu, Rong-Gui Du, Chang-Jian Lin

Journal of Electrochemistry

In this work, the concrete samples polluted by chloride ion were electrochemically treated using galvanostatic technique, and the distributions of chloride ion concentration and pH value in the polluted concretes were in-situ monitored by embedding a combined pH/Cl^- probe during the electrochemical chloride removal. The corrosion behaviors of reinforcing steel in the concrete were simultaneously studied by using linear polarization and electrochemical impedance spectroscopy techniques (EIS). The micro environment of the concrete and corrosion rate of steel were explored during the electrochemical chloride removal. It was indicated that the Cl^- concentration in the concrete pore solution decreased with …

Sensitivity Of Electrochemical Impedance Spectroscopy Measurements To Concrete Bridge Deck Properties, Hillary Mckenna Argyle

Theses and Dissertations

Numerous methods have been developed to measure corrosion potential relating to chloride infiltration in concrete, including an emerging application of electrochemical impedance spectroscopy (EIS). EIS involves measurements of electrical impedance to evaluate the corrosion potential of steel reinforcement in concrete. With EIS, current is injected vertically into the concrete bridge deck between the surface and the embedded reinforcing steel, usually the top mat, to evaluate the degree to which the reinforcing steel is protected from chloride infiltration by the entire bridge deck system. The objectives of this research were to 1) investigate the sensitivity of EIS measurements obtained at various …

Development Of A Chloride Concentration Sampling Protocol For Concrete Bridge Decks, Sharlan Renae Montgomery

Theses and Dissertations

As the primary cause of concrete bridge deck deterioration in the United States is corrosion of the steel reinforcement as a result of the application of chloride-based deicing salts, chloride concentration testing is among the most common techniques for evaluating the condition of a concrete bridge deck. The objectives of this research were to 1) compare concrete drilling and powder collection techniques to develop a sampling protocol for accurately measuring chloride concentrations and 2) determine the number of chloride concentration test locations necessary for adequately characterizing the chloride concentration of a given bridge deck. Laboratory experiments on concrete drilling and …

Fabrication And Enhancement Of Aluminum-Based Microchannel Devices, Paul Joseph Hymel

LSU Master's Theses

Microscale molding replication and transient liquid phase (TLP) bonding were used to fabricate Al-based microchannel heat exchangers (MHEs) and micro gas chromatograph (mGC) columns. Metal-based microchannel heat exchangers often experience corrosion as a result of their operating conditions. To address this problem, an internal anodization method was developed in Al microtubes by pulsing the flow of electrolyte through a microtube when the current dropped below a set value. The anodic aluminum oxide (AAO) films were characterized by scanning electron microscopy (SEM), focused ion beam (FIB) cross sections, and X-ray energy dispersive spectroscopy (EDS) to determine their growth rate and morphology. …

Magnesium-Titanium Alloys For Biomedical Applications, Ilona Hoffmann

Theses and Dissertations--Chemical and Materials Engineering

Magnesium has been identified as a promising biodegradable implant material because it does not cause systemic toxicity and can reduce stress shielding. However, it corrodes too quickly in the body. Titanium, which is already used ubiquitously for implants, was chosen as the alloying element because of its proven biocompatibility and corrosion resistance in physiological environments. Thus, alloying magnesium with titanium is expected to improve the corrosion resistance of magnesium.

Mg-Ti alloys with a titanium content ranging from 5 to 35 at.-% were successfully synthesized by mechanical alloying. Spark plasma sintering was identified as a processing route to consolidate the alloy …

Phosphate-Doped Borosilicate Enamel Coating Used To Protect Reinforcing Steel From Corrosion, Xiaoming Cheng

Doctoral Dissertations

"Phosphate-doped sodium borosilicate glasses were developed for enamel coatings to provide corrosion protection for reinforcing steel in concrete. Phosphates have low solubilities in borosilicate glasses, generally less than about 4 mol%, and are incorporated mainly as isolated PO₄^3- and P₂O₇^4- anions, along with some borophosphate bonds. With the addition of P₂O₅, the silicate network is repolymerized and tetrahedral borates are converted to trigonal borates, because the phosphate anions scavenge sodium ions from the borosilicate network. The addition of Al₂O₃ significantly increases the solubility of P₂O …

Corrosion Prevention And Control Training In An Immersive Virtual Learning Environment, Rustin Deane Webster

All ETDs from UAB

The majority of military education and training has not veered far from the days of chalk and talk instruction. Often with technological breakthroughs comes the proposal of the next revolution in multimedia instruction. Motion pictures to radios to educational television programs have all seemed to come and gone. The next wave of multimedia learning may involve more than a PowerPoint® presentation and lecture. Researchers continue to propose that Virtual Reality (VR) will find its true application and/or market in education and training. The objective of the project was to develop and provide a low-cost, scalable, and portable VR system containing …

Delamination Detection In Concrete Using Disposable Impactors For Excitation, Anjali Narendra Patil

Theses and Dissertations

Delaminations in concrete bridge decks result primarily from corrosion of the reinforcing bars (or rebar). This corrosion leads to volumetric expansion of the rebar. When the rebar expands, concrete cracks, and there is a localized separation of the concrete cover from the underlying concrete. Impact-echo testing is an effective technique to map delaminations on concrete bridge decks. However, mapping speed is limited by necessary retrieval of the impactor for traditional tests. To achieve higher scanning speeds, it is advantageous to use both a non-contact measurement (air-coupled impact-echo) and disposable-impactor excitation. Disposable impactors have the potential advantage of achieving greater deck …

Basic Principles And Applications Of Secm In Metal Corrosion, Fa-He Cao, Yan Xia, Wen-Juan Liu, Lin-Rong Chang, Jian-Qing Zhang

Journal of Electrochemistry

Scanning electrochemical microscopy (SECM) is chemical microscopy with higher spatial resolution. After 24 years of development, SECM has been widely applied in mapping and kinetics study of heterogeneous electron transfer in localized processes at solid-liquid or liquid-liquid interfaces. The fundamentals and recent advances of SECM in corrosion applications are described, including SECM mapping and kinetics on localized corrosion of metal or coating. Research work of SECM in corrosion by our group is also introduced. Future applications of SECM in corrosion are highlighted.

Applications Of Spectroscopic Ellipsometry In Corrosion Investigation, Ling-Jie Li, Yu-Ling He, Jing-Lei Lei, Sheng Tao Zhang

Journal of Electrochemistry

As a highly-sensitive and non-destructive in situ technique, spectroscopic ellipsometry has been widely applied in corrosion investigation to acquire the dynamic information of the “electrode-medium” interface during corrosion. This paper lays out some representative demonstrations in several established optical models used to interpret data obtained with spectroscopic ellipsometry in corrosion investigation. In addition, the latest trends in development of this technique are analyzed.

Iron-Magnesium Alloy Bioabsorbable Blood Stent, Kaitlyn Jarry, L Stanciu

The Summer Undergraduate Research Fellowship (SURF) Symposium

Bioabsorbable materials are fairly new and proper alloys for implantation in the body have not yet been established. There are a few polymers that have showed promise, but they do not provide the proper mechanical support that metal does. These materials would be used to create devices such as blood stents and orthopedic screws. Investigation into the properties of different alloys can help to establish a material that can be used for implanted devices that are only needed for a limited amount of time. In order to investigate these alloys many different experiments will to be run to test the …

A Real Case Study On The State Of Corrosion Of The Spanish Boats, José A Orosa, Juan José Galán, Mar Toledano

Journal of Marine Science and Technology–Taiwan

In this real case study we analyze various corrosion problems encountered in Spanish fleets and present possible solutions. As a first step, we developed a statistical analysis of the north Mediterranean Sea fleets to define the age of the vessels, hull construction material and main activities involved. As a result, different corrosion problems were identified as well as solutions like paint, sacrificial anodes and impressed currents, and of course, improved design. Generally, we can state that, according to the results obtained, a series of incidents have increased the repair and maintenance costs of the vessels in the area under study

Corrosion Activity In Precast Concrete Elements And Cementitious Closure Pours, Shabi Abbas Udaipurwala

All Theses

The use of prefabricated elements in the construction of highway bridges has been a common practice in the United States since 1950s. Precast concrete adjacent box beam girder bridges are quite popular given that the precast elements not only have structural capacity to span across the supports, but also form the bridge deck. These bridges have generally performed well during the initial years after construction, but recent failures in Pennsylvania and Indiana have aroused a nationwide alarm to investigate the causes of failure and find solutions to repair these bridges or develop design for new replacement bridges. It was found …

Structural Reliability Analysis Of Corroded Steel Girder Bridge, Mohammed Shaalan Al Badran

Department of Civil and Environmental Engineering: Dissertations, Theses, and Student Research

The natural aging, environmental impact, and appropriate design are certainly playing a serious role in safety of the bridges function. The functional safety of bridge constitutes a prime element of the transportation system serving commuters, passengers and freight. According to Federal Highway Administration, the steel bridges share represents a large amount of the United States’ bridges. In last century, the collapse of both the Silver Bridge at Point Pleasant, West Virginia over the Ohio River on December 15, 1967 and over the Mianus River Bridge in Connecticut on June 28, 1983 showed that steel corrosion has been the leading reason …

Multifunctional Corrosion Inhibition Behavior Of Zn-Al Calcined Layered Double Hydroxides For Steel Rebar In Nacl Solution, Xiao-Juan Zhang, Jing-Jing Wang, Shi-Gang Dong, Chang-Jian Lin

Journal of Electrochemistry

The Zn-Al layered double hydroxides (Zn-Al LDHs) and calcined products (Zn-Al CLDHs) were synthesized successfully under a routine air atmosphere. The results showed that both Zn-Al LDHs and Zn-Al CLDHs had obvious flake structures. The corrosion inhibition of Zn-Al CLDHs for steel rebar in NaCl solution was studied by electrochemical techniques. It was found that the corrosion rate of steel rebar decreased significantly after the steel rebar was treated by Zn-Al CLDHs in NaCl solution for 3 h. It was indicated that Zn-Al CLDHs could absorb Cl^- and release OH^- during their reconstruction process, which provided dual protection …

Evaluation Of Corrosion Properties Of Proprietary Metal Alloy Stents For In-Vivo Use, Michael David Bremner

Materials Engineering

To assess corrosion rates of metal alloy bio-absorbable stents an experimental set-up was designed to mimic the coronary artery environment. The artery was modeled using 4mm diameter Tecoflex tubing and the metal alloy stents were inserted into the tubing using a catheter. As is the case in cardiac surgery, the catheter with the stent and a microballoon were maneuvered to the desired position. The microballoon was then slowly inflated to expand the stent and compress it against the tubing walls. The catheter and microballoon were then withdrawn. A circulating pump system was set up to cycle fetal bovine serum (FBS) …

Comparison Of Polyurethane And Polysiloxane Coating Systems In Marine Environments, Jake Jarman, Jessica Salvatin

Materials Engineering

This project investigates the performance benefits of polysiloxane and polyurethane coating systems for corrosion protection in marine environments. PPG Industries Amercoat 450H and International Paint Interthane 990HS were the polyurethane topcoats tested. PPG Industries Ameron PSX 700 (New Blend) and International Paint Interfine 878 were the polysiloxane topcoats tested. Each coating was sprayed onto carbon steel panels that were prepared through hand blasting with glass beads. Scribed and unscribed panels were tested in a salt fog chamber for 1,200 hours according to ASTM Standard B0117-11 and in a UV/Humidifier for 1,650 hours according to ASTM Standard D4587-11. Panels were tested …

Performance Of Reinforced Concrete Beams Strengthened With Mechanically-Fastened Composite System Under Corrosive Environment, Amna Zaid Suwaid Al Nassibi

Theses

This study examines the effects of corrosion exposure on the flexural response of reinforced concrete (RC) beams strengthened with a powder-actuated fastened (PAF) composite system. Twenty-one RC beams were constructed and tested to failure under four-point bending. The corroded beams were subjected to 30, 60, and 100 days of accelerated corrosion that corresponded to measure tensile steel mass losses of 6, 11 and 18% respectively. Other test parameters included width of fiber reinforced polymer (FRP) composite strip, fastener length, and number of fasteners rows.

For the non-corroded beams, the PAF-FRP system resulted in up to 24% increase in beam flexural …

Evaluation Of Forging Strain For Maximum Grain Size In Open-Die Forged 6061 Aluminum, Eric Strehl

Materials Engineering

In an effort to maximize grain growth of open-die forged 6061 aluminum alloy parts, samples from three of Weber Metals’s suppliers (Hidal Co-Almex USA Inc., TST Inc., and Vista Metals Corp.; to be called Supplier H, Supplier T, Supplier V respectively) were cut into cylinders with diameters of 0.75˝ and heights of 2˝, and put through a simulated forging process and heat treatment. It is possible that additional alloying elements may be promoting or inhibiting grain growth in the final part. Maximizing grain growth for aluminum alloy parts results in improved resistance to intergranular corrosion. Samples from each vendor had …

A Study On The Cleaning And Modification Of Metal Surfaces By Direct Current Cathodic Electrolytic Plasma Process, Jiandong Liang

LSU Doctoral Dissertations

The processes of surface treatments or surface modifications, more formally known as surface engineering, tailor the surfaces of engineering materials. The treatments are usually intended to change physical properties such as thermal or electrical conductivity, modify the surface dimensions, i.e. roughness, etc. A novel surface treatment method, Electrolytic Plasma Process (EPP), was developed for coating purposes, in its early developmental stage. In this work, the major effort is to avoid using any environmental hazardous chemical (coatings) and to extend such its application to some new fields. The general response of the substrate material under electrolytic plasma process was summarized including …

In-Plant And Distribution System Corrosion Control For Reverse Osmosis, Nanofiltration, And Anion Exchange Process Blends, Samantha Jeffery

Electronic Theses and Dissertations

The integration of advanced technologies into existing water treatment facilities (WTFs) can improve and enhance water quality; however, these same modifications or improvements may adversely affect finished water provided to the consumer by public water systems (PWSs) that embrace these advanced technologies. Process modification or improvements may unintentionally impact compliance with the provisions of the United States Environmental Protection Agency’s (USEPA’s) Safe Drinking Water Act (SDWA). This is especially true with respect to corrosion control, since minor changes in water quality can affect metal release. Changes in metal release can have a direct impact on a water purveyor’s compliance with …

Assessment Of Damage In Concrete Structures Using Acoustic Emission, Marwa Abdelrahman

Theses and Dissertations

Evaluating the integrity of concrete structures is an essential procedure to ensure structural safety and durability. Non-destructive testing (NDT) is needed for localizing and characterizing the growing damage in existing structures and also for quality control of new structures. Visual inspection is a commonly used method; however it is not suitable for early detection of damage and very dependent on the experience of the inspector. More research is needed to establish advanced methods for structural health diagnosis such as acoustic emission (AE). Acoustic emission is notably sensitive to active damage in concrete structures. This thesis includes three studies that mainly …