Engineering Commons^™

Simulation And Behavior Of Corrosion Deteriorated Reinforced Concrete Members, M. A. Shayanfar, Amir Safiey

Amir Safiey

Several reinforced concrete (RC) infrastructures are now crumbling from corrosion of steel bars in concrete. The paper presents the recent advancements in analytical simulation of corrosion aftereffects on behavior of RC members. The model juxtaposes the experimental findings with analytical relationships. The implementation of the model into a nonlinear finite element formulation as well as the experimental and analytical backgrounds are discussed. The abilities of the resulted program have been studied by modeling some experimental specimens showing a reasonable agreement between the analytical and experimental findings.

A New Approach For Nonlinear Finite Element Analysis Of Reinforced Concrete Structures With Corroded Reinforcements, Mohsen A. Shayanfar, Amir Safiey

Amir Safiey

A new approach for nonlinear finite element analysis of corroded reinforcements in reinforced concrete (RC) structures is elaborated in the article. An algorithmic procedure for producing the tension-stiffening curve of

RC elements taking into consideration most of effective parameters, e.g.: the rate of steel bar corrosion, bond-slip behavior, concrete cover and amount of reinforcement, is illustrated. This has been established on both experimental and analytical bases. This algorithm is implemented into a nonlinear finite element analysis program. The abilities of the resulted program have been studied by modeling some experimental specimens showing a reasonable agreement between the analytical and experimental …

Corrosion Effects On Tension Stiffening Behavior Of Reinforced Concrete, M. A. Shayanfar, M. Ghalehnovi, Amir Safiey

Amir Safiey

The investigation of corrosion effects on the tensile behavior of reinforced concrete (RC) members is very important in region prone to high corrosion conditions. In this article, an experimental study concerning corrosion effects on tensile behavior of RC members is presented. For this purpose, a comprehensive experimental program including 58 cylindrical reinforced concrete specimens under various levels of corrosion is conducted. Some of the specimens (44) are located in large tub containing water and salt (5% salt solution); an electrical supplier has been utilized for the accelerated corrosion program. Afterwards, the tensile behavior of the specimens was studied by means …

Isolating Corrosion Of Steel Plates Coupled With Titanium, Anil Patnaik, X. Shan, M. Adams, T. Srivatsan, Craig Menzemer, Joe Payer

Craig Menzemer

Over twenty six percent of the bridges in the United States are structurally deficient or functionally obsolete. Corrosion of steel used in structures like bridges and buildings is a problem that has gained increased interest and focused concern. Steel is often the metal that is preferred for use in such applications due to a synergism of ease of availability, acceptable mechanical properties and cost effectiveness. Through the years, titanium has grown in strength, stature and significance to be recognized as an emerging high performance metal that is both stronger and lighter than steel. A distinctive property of titanium and its …

Rock Bolt Corrosion - An Experimental Study, Naj Aziz, P Craig, Jan Nemcik, Faisal Hai

Faisal I Hai

The effect of long term exposure of full size bolts to corrosive environments is presented. A special test rig was used to test four bolts under different loading conditions. Four X-grade identical profile bolts, each 21·7 mm core diameter (23·7 mm full diameter) were subjected to prolonged corrosion testing using acid sulphate water. The pH value of the circulated water varied between 3·4 and 4·3. The corrosion exposure test period lasted 3·5 years. Two bolts were axially loaded to 10 t and 20 t force respectively, the third bolt was subjected to a 360 Nm torsion load and the fourth …

Extrinsic Influence Of Environment On The Corrosion Behaviour Of Enamel-Coated Steel Dowel Bars, Srikanth Bajaj, Anil Patnaik, Joe Payer, Robert Liang, Kannan Manigandan, Tirumalai Srivatsan

Anil Patnaik

A new type of enamel coated dowel bars for use as concrete pavements has been recently developed and implemented. A gradual deterioration of such bars can occur due to corrosion occurring at locations of the fine microscopic cracks and other defects in the coating. The results of a study aimed at evaluating and understanding the corrosion resistance of such dowel bars is presented and comparisons made with corresponding epoxy-coated dowel bars. Identical defects were introduced onto the surface of the dowel bars with the two types of coatings. The extrinsic influence of environment and resultant corrosion based on type, location …

Isolating Corrosion Of Steel Plates Coupled With Titanium, Anil Patnaik, X. Shan, M. Adams, T. Srivatsan, Craig Menzemer, Joe Payer

Anil Patnaik

Over twenty six percent of the bridges in the United States are structurally deficient or functionally obsolete. Corrosion of steel used in structures like bridges and buildings is a problem that has gained increased interest and focused concern. Steel is often the metal that is preferred for use in such applications due to a synergism of ease of availability, acceptable mechanical properties and cost effectiveness. Through the years, titanium has grown in strength, stature and significance to be recognized as an emerging high performance metal that is both stronger and lighter than steel. A distinctive property of titanium and its …

Extrinsic Influence Of Environment On The Corrosion Behaviour Of Enamel-Coated Steel Dowel Bars, Srikanth Bajaj, Anil Patnaik, Joe Payer, Robert Liang, Kannan Manigandan, Tirumalai Srivatsan

Robert Y. Liang

A new type of enamel coated dowel bars for use as concrete pavements has been recently developed and implemented. A gradual deterioration of such bars can occur due to corrosion occurring at locations of the fine microscopic cracks and other defects in the coating. The results of a study aimed at evaluating and understanding the corrosion resistance of such dowel bars is presented and comparisons made with corresponding epoxy-coated dowel bars. Identical defects were introduced onto the surface of the dowel bars with the two types of coatings. The extrinsic influence of environment and resultant corrosion based on type, location …

System Reliability Analysis For Anchor-Stabilised Slopes Considering Stochastic Corrosion Of Anchors, Lin Li, Robert Liang, Hanlong Liu

Robert Y. Liang

In this paper, a methodology using Monte Carlo simulation method was developed in conjunction with the modified limiting equilibrium method of slices. Additionally, the time-dependent deterioration of bond capacity of corroding soil anchors was developed in this methodology due to the attack of chlorides. Uncertainties of anchor-related variables and soil parameters were considered using pertinent statistical descriptors. Furthermore, the inherent stochastic nature of the corrosion and degradation process for the anchor/slope system was identified and incorporated in the simulation. A PC-based software, C-UASLOPE, has been coded to allow for handling of complex slope geometry, soil profile and groundwater conditions. An …

Gfrp Reinforced Concrete Bridge Decks (Kyspr 96-169), David Deitz, Issam Harik, Hans Gesund

Issam E. Harik

This report investigates the application of glass fiber reinforced polymer (GFRP) rebars in concrete bridge decks as a potential replacement or supplement to conventional steel rebars. Tests were conducted to determine the material properties of the GFRP reinforcement, and experiments were performed to study aspects of GFRP rebar placement in actual bridge decks. These included observation of GFRP rebar handling characteristics and worker response during construction. Load tests of full-scale reinforced concrete specimens were conducted to evaluate the characteristics of three reinforcing schemes: (1) an epoxy coated steel (ECS) reinforcing scheme; (2) a GFRP reinforcing scheme, and (3) a Hybrid …

Rfid Tags For Detecting Concrete Degradation In Bridge Decks, Tyler J. Lesthaeghe, Samuel Frishman, Stephen D. Holland, Terry J. Wipf

Tyler J Lesthaeghe

Steel reinforcing bar (rebar) corrosion due to chlorine ingress is the primary degradation mechanism for bridge decks. In areas where rock salt is used as a de-icing agent, salt water seeps into the concrete through cracks, causing corrosion of the rebar and potentially leading to catastrophic failure if not repaired. This project explores the use of radio frequency identification (RFID) tags as low-cost corrosion sensors. RFID tags, when embedded in concrete, will fail due to corrosion in the same manner as rebar after prolonged exposure to salt water. In addition, the presence of salt water interferes with the ability to …

Combinatorial Approach To Turbine Bond Coat Discovery, Christopher Metting, Johnathan Bunn, Ellen Underwood, Stephen Smoak, Jason Hattrick-Simpers

Jason R. Hattrick-Simpers

No abstract provided.

Comparing Electrochemical Impedance Spectroscopy Methods For Estimating The Degree Of Delamination Of Organic Coatings On Steel, S. A. Mccluney, S. N. Popova, Branko N. Popov, Ralph E. White, R. B. Griffin

Ralph E. White

Electrochemical impedance spectroscopy (EIS) was used to evaluate the degree of delamination of the epoxy primer Uniprime ED-4¹ electrocoated on phosphate-treated cold-rolled steel in 3.5% NaCl exposed to air. Specimens with coating thicknesses of 20.3 and 20.8 µm and surface areas of 78.5 cm² were used. Coating parameters were obtained using a circuit-analog model. The area of delamination was estimated using several EIS parameters, including the pore resistance and the break point frequency. These values were compared to the corroded area determined visually. All methods considered exhibited a strong correlation over some or all of the range of …

A Mathematical Model For The Initial Corrosion Rate Of A Porous Layer On A Rotating Disk Electrode, William E. Ryan, Ralph E. White, S. L. Kelly

Ralph E. White

A mathematical model is presented for the initial corrosion rate of a porous layer on a rotating disk electrode. The model is used to predict the corrosion potential and corrosion current density for a porous electrode made of pure iron in aerated caustic solutions. The dependence of these predictions on some of the properties of the porous layer is presented. It is shown that the corrosion rate depends significantly on the specific surface area of the porous electrode.

Development Of A New Electrodeposition Process For Plating Of Zn-Ni-X (X = Cd, P) Alloys: I. Corrosion Characteristics Of Zn-Ni-Cd Ternary Alloys, Anand Durairajan, Bala S. Haran, Ralph E. White, Branko N. Popov

Ralph E. White

A new Zn-Ni-Cd plating process was developed which offers a unique way of controlling and optimizing the Ni and Cd contents in the final deposit. Zinc-nickel-cadmium alloy was deposited from a 0.5 M NiSO₄ + 0.2 M ZnSO₄ bath in the presence of 0.015 M CdSO₄ and 1 g/L nonyl phenyl polyethylene oxide. Using this process a Zn-Ni-Cd ternary alloy, with a higher nickel content as compared to that obtained from conventional Zn-Ni baths, was synthesized. The Zn-Ni-Cd alloy coatings deposited from an electrolyte containing 0.015 M (0.3%) CdSO₄ has a Zn to Ni ratio of …

A Review Of Survivability And Remedial Actions Of Tidal Current Turbines

Faculty of Engineering University of Malaya

Tidal current energy is one of the most predictable ocean renewable energies. Survivability of the device used to harness tidal power and its remedial actions are critical to ensure a successful power generation. Marine environment is harsh with the continuous attacks of waves, current saline water and microorganism. Support structures are discussed including gravity base, monopile, tripod/piled jacket and floating structure. Extreme weather increases the wave height and current speed to produce high loading at the turbine. Support structure is designed to sustain the loadings from the extreme weather. Protective seabed unit should be included to prevent the seabed scouring. …

Engineering And Sustainability Performance Of Self-Compacting Palm Oil Mill Incinerated Waste Concrete

Faculty of Engineering University of Malaya

The different stages in the processing of palm oil generate various types of waste by-products, which have to be disposed of appropriately for a cleaner environment and to reduce pollution. In this study, palm oil clinker (POC), one of the by-products of the palm oil mill, was utilized in the production of self-compacting concrete (SCC). SCC has diverse types of structural application due to its own enhanced self-consolidating behaviour. The proportioning of the mixes was based on particle packing, which integrates both aggregate packing and void volume for a mix of aggregates. Combinations of POC and natural aggregate were studied …

Thermodynamic Considerations Of The Corrosion Of Nickel Ferrite Refractory By Na3alf6-Alf3-Caf2-Al 2o3 Bath, Raymond Longbottom, Sharon Nightingale, Brian Monaghan

Brian Monaghan

Thermodynamic analysis was carried out to interpret the results of corrosion testing of nickel ferrite samples in cryolite-based baths. The equilibrium between cryolite-based baths and nickel ferrite was considered. Isopleths between cryolite-based baths and nickel ferrite confirmed that for the temperature range of interest (1223-1273 K) there was limited solubility of nickel ferrite in the bath. To better understand the formation of the metal from nickel ferrite, the effect of reducing potentials on nickel ferrite and nickel ferrite-cryolite-based bath systems were considered. The formation of a metal phase was predicted at relatively high pO2. The metal phase was nickel-rich at …

In Vitro Studying Corrosion Behaviour Of Biocorrodible Mg Alloys, Sina S. Jamali, Simon Moulton, Maria Forsyth, Gordon G. Wallace

Gordon Wallace

The idea of bioabsorbable/biocorrodible stents has gained increasing attention in the last decade. Permanent coronary stents, traditionally made from 316L grade stainless steel, are routinely used for the treatment of blocked arteries. However, these stents can cause complications such as restenosis, thrombosis and the need for the patient to undergo prolonged antiplatelet therapy. Biodegradable metal stents provide an opportunity for the stent to remain in place for a period to ensure restoration of function and then degrade through a carefully controlled bio-corrosion process. Among the number of potentially suitable materials, Magnesium alloys have shown great promise as a stent material …

Corrosion Of Magnesium And Aluminum In Palm Biodiesel: A Comparative Evaluation

A.S. Md Abdul Haseeb

The present study aims to investigate the comparative corrosion of light-weight metals such as aluminum and magnesium in palm biodiesel. Immersion test at room temperature was carried out for each metal for 1440 h. Sample characterization techniques employed include weight loss measurement, SEM (scanning electron microscope), XRD (X-ray diffraction), TAN (total acid number) and FTIR (Fourier transform infrared spectroscopy). Results showed that the corrosion rate of magnesium was much higher compared to that of aluminum. The surface morphology revealed a significant difference between the biodiesel exposed aluminum and magnesium specimens. Upon exposure to biodiesel, the magnesium surface was found to …

Degradation Of Automotive Materials In Palm Biodiesel

A.S. Md Abdul Haseeb

As compared to petroleum diesel, biodiesel is more corrosive for automotive materials. Studies on the characterization of corrosion products of fuel exposed automotive materials are scarce. Automotive fuel system and engine components are made from different ferrous and non-ferrous materials. The present study aims to investigate the corrosion products of different types of automotive materials such as copper, brass, aluminum and cast iron upon exposure to diesel and palm biodiesel. Changes in fuel properties due to exposure of different materials were also examined. Degradation of metal surface was characterized by digital camera, SEM/EDS and X-ray diffraction (XRD). Fuel properties were …

Effect Of Temperature On The Corrosion Behavior Of Mild Steel Upon Exposure To Palm Biodiesel

A.S. Md Abdul Haseeb

Recently biodiesel, as an alternative fuel is getting more significance to replace diesel fuel completely or partially. However, corrosion of automotive materials in biodiesel is a major concern as this can reduce engine life. This study aims to investigate the corrosion behavior of mild steel at three different temperatures such as room temperature, 50 and 80 °C. Static immersion tests in B0 (diesel), B50 (50% biodiesel in diesel), B100 (biodiesel) were carried out for 1200 h. At the end of the tests, corrosion characteristic was investigated by weight loss measurements and changes of the exposed metal surface. Fuels were analyzed …

Compatibility Of Automotive Materials In Biodiesel: A Review

A.S. Md Abdul Haseeb

Use of biodiesel in automobile can significantly reduce our dependence of fossil fuel and help reduce environmental pollution. However, there are concerns over the compatibility of currently used automotive materials in biodiesel. A few automobile manufacturers extended their warranty only to lower blends of biodiesel (e.g. B5). Higher blends (e.g. B50 or B100) are still not covered by warranty. In automobile fuel system, metallic materials like ferrous alloy and non-ferrous alloys, and elastomers come in contact with fuel. Biodiesel, having different chemical characteristics from diesel, can interact with materials in a different way. It can cause corrosive and tribological attack …

Comparative Corrosive Characteristics Of Petroleum Diesel And Palm Biodiesel For Automotive Materials

A.S. Md Abdul Haseeb

Corrosive characteristics of biodiesel are important for long term durability of engine parts. The present study aims to compare the corrosion behavior of aluminum, copper and stainless steel in both petroleum diesel and palm biodiesel. Immersion tests in biodiesel (B100) and diesel (B0) were carried out at 80 °C for 1200 h. At the end of the test, corrosion characteristic was investigated by weight loss measurements and changes on the exposed metal surface. Surface morphology was examined by optical microscope and scanning electron microscopy with energy dispersive X-ray analysis (SEM/EDS). Fuels were analyzed by using TAN analyzer, FTIR, GCMS and …

Corrosion Characteristics Of Copper And Leaded Bronze In Palm Biodiesel

A.S. Md Abdul Haseeb

Biodiesel has become more attractive as alternative fuel for automobiles because of its environmental benefits and the fact that it is made from renewable sources. However, corrosion of metals in biodiesel is one of the concerns related to biodiesel compatibility issues. This study aims to characterize the corrosion behavior of commercial pure copper and leaded bronze commonly encountered in the automotive fuel system in diesel engine. Static immersion tests in B0, B50 and B100 fuels were carried out at room temperature for 2640 h. Similar immersion tests in B0, B100 and B100 (oxidized) fuels were also conducted at 60 °C …

Supercritical Water Oxidation Process And Its Application In Treatment Of Industrial Wastewater (Persian Paper), N. Daneshvar, S. Aber, Mir Saeed Seyed Dorraji, M. Zarei, M. H. Rasoulifard

Mir saeed Seyed Dorraji

In the last two decades, supercritical water has become an interesting medium for chemistry. One of its most investigated applications is the oxidative treatment of aqueous wastes containing organic compound in the so-called “supercritical water oxidation”. In this technology, supercritical water acts as a non-polar solvent. Consequently, even non-polar organic compounds and gases like oxygen become completely miscible with the supercritical fluid. During the supercritical water oxidation (SCWO) process, the organic compounds react completely with oxidant –mostly oxygen- in a single phase reaction forming CO2 and H2O. The hetero-atoms present in the organic wastes are transformed into the mineral acids. …

Thermal Stability Of Electrodeposited Liga Ni-W Alloys For High Temperature Mems Applications

A.S. Md Abdul Haseeb

For thermally stable LIGA materials for high temperature MEMS applications LIGA Ni-W layers and micro testing samples with different compositions (15 and 5 at% W) were electrodeposited. In order to investigate the thermal stability the Ni-W layers were annealed at different temperatures (300-700°C) and for different durations (1, 4, 16 h). Their microstructure and micro-hardness were than analysed after annealing and compared with those of as-deposited states. The observed microstructures show, in comparison to pure LIGA nickel, a small grain growth and a relatively stable structure up to 700°C. The micro-hardness values of the LIGA Ni-W layers are higher than …

Avoid Sulfuric Acid Corrosion In Metallic Stacks, João F. Gomes

João F Gomes

Acidic gaseous effluents frequently cause corrosion on metallic stacks. This paper presents a method for prevision of probability of corrosion occurrence caused by gaseous effluents containing sulphur oxides which is based on the sulphur trioxide and moisture content measured in stack