2020 |
Melchers RE, Ahammed M, 'Extreme Value Statistics for Pitting Corrosion of Steel Pipelines', ACMSM25. Proceedings of the 25th Australasian Conference on Mechanics of Structures and Materials, Brisbane, Australia (2020) [E1]
|
|
|
2019 |
Cartwright B, Mulcahy L, Melchers R, Magoga T, Aksu S, McGuckin D, Renilson M, 'Seaway loads applied to a frigate by the smoothed particle hydrodynamics technique', RINA, Royal Institution of Naval Architects - IMC 2019: Pacific International Maritime Conference, Sydney, Australia (2019) [E1] |
|
|
2019 |
Mokhtari M, Melchers RE, 'Next generation fracture prediction models of pitted pipelines for cleaner energy transportation', Proceedings of the International Offshore and Polar Engineering Conference, Honolulu, Hawaii (2019) [E1] |
|
|
2019 |
Petersen RB, Melchers RE, Hossain MM, Chaves IA, 'The corrosion of mild steel in contact with seawater and sand', Corrosion and Prevention 2019, Melbourne, Australia (2019) [E1]
|
|
|
2019 |
Ehsman J, Melchers R, Green W, 'Durability of reinforced concrete marine structures up to 109 years', FIB 2018 - Proceedings for the 2018 fib Congress: Better, Smarter, Stronger (2019)
© 2019 by the fib. All rights reserved. For steel reinforced concrete marine structures, a common assumption in practice is that corrosion will commence once the chloride threshol... [more]
© 2019 by the fib. All rights reserved. For steel reinforced concrete marine structures, a common assumption in practice is that corrosion will commence once the chloride threshold limit has been reached and that this automatically results in aggressive corrosion activity, cracking and severe cross-sectional area losses in the steel. Historically the literature suggests chloride concentration is a critical mechanism for corrosion in a marine environment. Recently this view has been questioned with the discovery of many reinforced concrete structures surviving for long periods of time despite very high chloride levels at the reinforcement. This paper reports of investigations of several marine structures, of ages 40 years, 57 years, 70 years and 109 years where little visible damage to the concrete surface was observed, despite high chloride content at the depth of reinforcement. It is surmised that for the marine structures investigated that the "active corrosion model" and "metastable pitting and pit growth mechanistic considerations" are contributory explanations to why little visible damage to the concrete surface was observed despite high chloride content at the depth of reinforcement.
|
|
|
2019 |
de Baere K, van Haelst S, Luyckx D, de Baere S, Boon N, van Halbeek S, et al., 'Corrosion of steel and other wreckage in the Belgian North Sea', Corrosion and Prevention 2019, Melbourne, Australia (2019) [E1] |
|
|
2019 |
Hossain MM, Petersen RB, Melchers RE, Kannan MB, Chaves IA, 'Marine Corrosion Of Mild Steel In Particulate Media', Corrosion and Prevention 2019, Melbourne, Australia (2019) [E1]
|
|
|
2019 |
Jardim do Nascimento B, Chaves IA, Masia MJ, Melchers RE, 'Corrosion behaviour of mortar embedded wall-ties in natural and artificial environments', Corrosion and Prevention 2019, Melbourne, Australia (2019) [E1]
|
|
|
2019 |
Zeman A, Melchers RE, 'Observations of atmospheric corrosion in an aggressive marine environment', Corrosion and Prevention 2019, Melbourne, Australia (2019) [E1] |
|
|
2019 |
Melchers RE, 'Long-term development of pitting corrosion for steels in water injection and production pipelines', Corrosion and Prevention 2019, Melbourne, Australia (2019) [E1] |
|
|
2019 |
Jeffrey R, Melchers RE, 'Measuring corrosivity in immersion conditions', Corrosion and Prevention 2019, Melbourne, Australia (2019) [E1]
|
|
|
2019 |
Rosen J, Chaves I, Sterjovski Z, Melchers R, 'Corrosion of welded high strength steels immersed in seawater', Corrosion and Prevention 2019, Melbourne, Australia (2019) [E1]
|
|
|
2018 |
Jardim Do Nascimento B, Chaves IA, Masia MJ, Melchers RE, 'A field investigation into long-term corrosion of metal wall ties in masonry veneer construction', Proceedings of the 10th Australasian Masonry Conference. Masonry Today and Tomorrow, Sydney, Australia (2018) [E1]
|
|
|
2018 |
Potts A, Jayasinghe K, Kilner A, Melchers R, Chaplin CR, 'Advancements in guidance for the specification and assessment of mooring steel wire rope', Proceedings of the Annual Offshore Technology Conference (2018)
© 2018, Offshore Technology Conference. Prior to the SCORCH JIP, industry guidance for steel wire ropes specified only a maximum service life for various rope constructions, provi... [more]
© 2018, Offshore Technology Conference. Prior to the SCORCH JIP, industry guidance for steel wire ropes specified only a maximum service life for various rope constructions, providing no insight into the corrosion degradation processes affecting mooring ropes at different locations in the mooring line and under different working conditions, or to potential differences in manufacture. One of the objectives of the SCORCH JIP was to address this gap in knowledge by providing design guidance on the specification of mooring wire ropes and analytical tools to estimate the design service life of mooring wire ropes for particular site conditions, especially in tropical waters. In the wire rope component of the JIP, field recovered specimens were examined and field tests on wires and wire ropes were performed to quantify the effects of external factors driving degradation of wire ropes in marine environments, including: protective coating; blocking compound, temperature, flow velocity, oxygenation and dynamic loading. Failure modes for wire rope were analysed based on the examination of recovered samples from in- service wire ropes, inspection records from different floating production units (FPUs), reported experiments in the field and experiments in literature. Experimental testing (both field tests and laboratory tests) of individual wire strands and complete wire rope constructions were carried out at a number of locations with varying environmental conditions. These data were then analysed to derive a phenomenological model that represents the observed behaviour of both ropes and individual wire layers. Amongst the key findings of the SCORCH JIP investigation was that the corrosion endurance of steel wire rope mooring lines is largely driven by the longevity of the galvanizing or other galvanic protecting coating, and the blocking compound, which forestall the direct corrosion loss of metallic area of the relatively small steel wires. Two major mechanisms by which zinc oxidation occurs and the major environmental contributors to the acceleration of wire degradation were identified; and efficacy of various rope protection methods were assessed. A predictive model was derived which characterised the rate of zinc dissolution, performance of blocking compound and corrosion rates for different exposure and working conditions. The outcome of the wire rope component of the SCORCH JIP was a significant advancement in industry knowledge on the corrosion behaviour of steel mooring wire ropes.
|
|
|
2018 |
Jayasinghe K, Potts A, Kilner A, Melchers R, 'Mooring chain wear experiments and findings', Proceedings of the Annual Offshore Technology Conference (2018)
Copyright © 2018, Offshore Technology Conference. Whilst mooring chain design practice has traditionally considered wear and corrosion together under a single allowance for materi... [more]
Copyright © 2018, Offshore Technology Conference. Whilst mooring chain design practice has traditionally considered wear and corrosion together under a single allowance for material loss, the two phenomena are influenced by different factors whereby they may act synergistically to accelerate degradation rates or act completely independently. As chain wear has been attributed to both the acceleration of corrosion-related degradation and the cause of chain failures and early mooring repairs by itself, it was investigated as part of the SCORCH JIP. An extensive literature review and meta-analysis of wear research was carried out in order to determine a framework for assessing the wear of mooring chains. The literature review found that the phenomenon of wear in general and mooring chain wear in particularly was not well understood, with little agreement as to a general analytical model for wear prediction. The particular wear regimes under which mooring chain wear occurs was identified and a critical analysis of available data on mooring chain wear was carried out where it was determined that experimental conditions were likely to have been outside of the bounds of validity for what would be experienced in the field. A generic formulation for chain wear was presented, where the amount of wear is proportional to the work done at the interlink contact due to the relative sliding of the chain links. Supplementary to the literature review, a series of wear tests of full-scale mooring chain links were carried out under varying load conditions for different grades of chain. These tests were used to determine empirical coefficients for the prediction of chain wear. A model for wear prediction was presented based on the position of the chain in the mooring line, the tension in the line and the relative motion of the chain links. The evolution of the contact surface between chain links was modelled using 3D geometries of idealized chain links in order to determine a relationship between the volume of worn metallic area and the depth of wear, which can be more easily measured in-service.
|
|
|
2018 |
Potts A, Kurts P, Jayasinghe K, Kilner A, Melchers R, Lee T, Chaplin R, 'SCORCH JIP - Overview of Project and summary of findings', Proceedings of the Annual Offshore Technology Conference (2018)
Copyright 2018, Offshore Technology Conference. Operators have, in the past, experienced high rates of corrosion for mooring systems in warm waters above those allowed for in trad... [more]
Copyright 2018, Offshore Technology Conference. Operators have, in the past, experienced high rates of corrosion for mooring systems in warm waters above those allowed for in traditional design guidance. The Joint Industry Project (JIP) for Seawater Corrosion of wire Rope and mooring Chain (SCORCH) was carried out with the participation of over twenty five offshore platform operators, equipment manufacturers, regulators and classification societies to address gaps in industry knowledge on the corrosion of steel wire rope and mooring chain, particularly in tropical waters. The five-year project involved a broad range of research from literature review through to field experiments, examination of recovered in-service components and derivation of generalised corrosion models. Coupons of several grades of chain were deployed for a two year period at a number of sites to account for variation in temperature, oxygenation, current/wave action and water quality. Full-size chain links and lengths of smaller chain were also deployed for comparison, with special laboratory tests to investigate the effect of nutrient content on microbiologically influenced corrosion (MIC). Wire rope tests were carried out for a similar variation of environmental conditions as the chain tests. A range of specimens including individual wire strands, and wire rope sections with varying levels of blocking compound, jacketing and galvanic protection were subject to exposure for a period of three years and 6 months. An extensive industry-wide survey of in-service and retired mooring components was also carried out to supplement these experiments. A standardised procedure for corrosion inspection was distributed to participants and a database of detailed wire rope and chain corrosion measurements was collated from approximately 30 floating production units (FPUs) operating in tropical waters in Asia, Africa and the Americas. Some recovered specimens were subject to more extensive examination, including 3D laser scanning and tensile break tests. The SCORCH JIP advanced knowledge in the field of mooring corrosion by providing guidance on inspection and integrity management methodologies, unique insight into the factors affecting the corrosion performance of steel wire rope and mooring chain, and generalised predictive corrosion models for the assessment of mooring corrosion. These recommendations are presented in the following paper.
|
|
|
2018 |
Melchers RE, Ahammed M, 'Maximum pit depth variability in water injection pipelines', Proceedings of the Twenty-eighth (2018) International Offshore and Polar Engineering Conference, Sapporo, Japan (2018) [E1]
|
|
|
2018 |
Watt MA, Melchers RE, Jeffrey R, 'Long-term corrosion of steel chains on Pacific Ocean beach sand', Corrosion & Prevention 2018, Adelaide, SA (2018) [E1]
|
|
|
2018 |
Petersen RB, Melchers RE, 'The influence of soil moisture on the corrosion of mild steel in clays after one year of exposure', Corrosion & Prevention 2018, Adelaide, SA (2018) [E1] |
|
|
2018 |
Jardim do Nascimento B, Chaves I, Masia MJ, Melchers RE, 'Long-term atmospheric corrosion of mortar embedded wall-ties', Corrosion & Prevention 2018, Adelaide, SA (2018) [E1]
|
|
|
2018 |
Melchers R, Petersen RB, Wells T, 'Further new interpretations of the corrosion of ferrous metals in soils', Corrosion & Prevention 2018, Adelaide, SA (2018) [E1]
|
|
|
2018 |
Liang MX, Melchers RE, Chaves IA, 'Pitting corrosion of 5005 aluminium alloys in the temperate seawater immersion environment', Corrosion and Prevention 2018, Adelaide, SA (2018) [E1]
|
|
|
2018 |
Chaves IA, Melchers R, 'Failure Prediction of Mild-Steel Welds due to Climate Change Influenced Marine Corrosion', Proceedings of the 28th International Offshore and Polar Engineering Conference, Sapporo, Japan (2018) [E1]
|
|
|
2018 |
Melchers RE, Chaves IA, 'Durability of reinforced concrete bridges in marine environments', MAINTENANCE, SAFETY, RISK, MANAGEMENT AND LIFE-CYCLE PERFORMANCE OF BRIDGES, Swinburne Univ Technol, Melbourne, AUSTRALIA (2018)
|
|
|
2017 |
Cartwright BK, Groenenboom PHL, Renilson MR, Melchers RE, 'Exploiting particle methods to investigate the structural integrity of maritime platforms', 9th Australasian Congress on Applied Mechanics, ACAM 2017 (2017)
© 2017 National Committee on Applied Mechanics. All Rights Reserved. Maritime assets such as ships and offshore platforms are major investments. Their effective management is impo... [more]
© 2017 National Committee on Applied Mechanics. All Rights Reserved. Maritime assets such as ships and offshore platforms are major investments. Their effective management is important. Their management plans should optimise asset availability, effective lifetime and functionality and reduce downtime for repairs. Together these aspects will improve safety, risk-management and cost-effectiveness. Difficult aspects relate to the wave loading on the asset and how to accurately model this both at any point in time, and over a period of time. This paper addresses recent developments in smoothed particle hydrodynamics (SPH) technology that significantly improve the modelling of dynamic fluid environments, including the ocean wave environment for maritime applications. The improved modelling of the wave environment enables the fluid-structure interaction (FSI) of a floating structure and the waves to be assessed. From this FSI and using finite element analysis techniques, the potential for non-linear failure behaviours in critical load-bearing structures can be predicted with greater confidence. Specific enhancements to SPH algorithms discussed herein are spatially-varied initial particle distributions, pressure correction, particle re-distributions, gravity initialisation, pressure sensors and translating active domains. Also discussed are practical aspects of the implementation that improve the ease of modelling real-world scenario such as contact interfaces, damping zones and wave making concepts. The connection between these SPH enhancements and existing features in commercial finite element analysis packages facilitate the implementation of the new assessment approach for maritime assets.
|
|
|
2017 |
Chaves IA, Fiedler T, Melchers RE, Taherishargh M, 'Corrosion trials of composite perlite aluminium foam', EUROCORR 2017 - The Annual Congress of the European Federation of Corrosion, 20th International Corrosion Congress and Process Safety Congress 2017 (2017)
© 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim. All rights reserved. Lightweight composite materials such as syntactic perlite aluminium foams have been gaining much atte... [more]
© 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim. All rights reserved. Lightweight composite materials such as syntactic perlite aluminium foams have been gaining much attention from the automotive, aerospace and nautical industries due to their superior mechanical and energy absorbing properties. Yet, there is still no empirical evidence of its mechanical performance under extreme corrosive marine environments. This study reports on 18 month corrosion field trials of such composite foam immersed in natural temperate marine waters off the southeast coast of Australia. Further, natural fresh water corrosion trials were also performed on the foams in order to quantify potential long-term phenomenological factors. Unloading Young's modulus, 1% offset yield stress as well as plateau stress after exposure fall within the scatter of previously reported unexposed samples. The results indicate no short-term loss of mechanical performance for natural exposure conditions. Reasons and implications are discussed.
|
|
|
2017 |
Chaves IA, Krismer S, Melchers RE, 'Short and long-term effect of HAZ microstructure on the marine corrosion of low-carbon steel weldments', EUROCORR 2017 - The Annual Congress of the European Federation of Corrosion, 20th International Corrosion Congress and Process Safety Congress 2017 (2017)
© 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim. All rights reserved. Welds on mild and low alloy steels exposed to the marine environment are known to be prone to high le... [more]
© 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim. All rights reserved. Welds on mild and low alloy steels exposed to the marine environment are known to be prone to high levels of corrosion. Pitting usually is the critical form of attack. Quantification of the relative and absolute maximum pit depths that occur is important for predicting future and remaining structural life but long term data is scarce. This study reports on a comparison of pit depths measurements on longitudinally welded mild steel exposed for 3.5 years to samples of homogeneous microstructure that simulate the various microstructural regions present in a heat affected zone. Samples from a normalized fine grained mild steel pipe were heat treated to produce a coarse grain microstructure, a spheroidised microstructure, a quenched microstructure, and a quenched and tempered microstructure. All data sets are from samples immersed in natural temperate marine waters off the southeast coast of Australia. The observed results provide support for the notion that the microstructural changes induced within the heat affected zone of a weld do contribute to increased corrosion rates in this region. Reasons and implications are discussed.
|
|
|
2017 |
Wang X, Melchers RE, 'The relative influence of MIC in the channelling corrosion of water injection pipelines (WIPs)', EUROCORR 2017 - The Annual Congress of the European Federation of Corrosion, 20th International Corrosion Congress and Process Safety Congress 2017 (2017)
© 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim. All rights reserved. Water injection of sea and other waters is widely used in the oil and gas extraction industry to incr... [more]
© 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim. All rights reserved. Water injection of sea and other waters is widely used in the oil and gas extraction industry to increase the production from individual, nearly depleted, wells. In some cases severe internal corrosion, mainly at the 6 o'clock position has been observed. This may threaten the safety of the pipelines. In other cases corrosion was found to be very mild, even though superficially the operational conditions are very similar. Field observations have shown a high presence of various bacteria associated with corrosion present in all pipelines. Some operators inject nitrate along the pipes into the wells. Earlier detailed examination of several field cases proposed the main driver of channelling corrosion is under-deposit corrosion and that MIC may contribute to this if nitrate injection is used. This concept was investigated in an experimental study using scale model carbon steel pipe specimens with deposits and simulated deoxygenated seawater environment. Variables include the use of fresh seawater, seawater treated with filtration and ultraviolet (UV) irradiation and seawater with added nitrates. After 180 and 360 days exposure the specimens showed increased corrosion under deposits for natural seawater and even more for seawater with added nitrate. The results are consistent with observations for corrosion in polluted seawaters. Together with periods during which deposits can form, they provide a rational explanation for channelling corrosion.
|
|
|
2017 |
Melchers RE, Chaves I, Pape T, 'Long term durability of reinforcement in Class A and Class B concretes in Pacific Ocean marine environment', EUROCORR 2017 - The Annual Congress of the European Federation of Corrosion, 20th International Corrosion Congress and Process Safety Congress 2017 (2017)
© 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim. All rights reserved. This paper compares the actual field performance of 293 Class B reinforced concrete headstocks suppor... [more]
© 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim. All rights reserved. This paper compares the actual field performance of 293 Class B reinforced concrete headstocks supporting 879 Class A reinforced concrete piles. These formed the substructure of a bridge constructed in 1935 and exposed for more than 80 years to tropical Pacific Ocean coastline conditions. Field inspections of the bridge at various stages during its life showed that the Class B concretes exhibited signs indicating active reinforcement corrosion after 50 years service but the Class A concretes exhibited few signs of active reinforcement corrosion. Records and historical information show that the only significant difference between the concretes is that the Class A concretes were made with higher cement contents than the Class B concretes. Visual inspection when the bridge was demolished in 2012 indicated no obvious differences in workmanship. Investigations of the concrete and the reinforcement steel at various times during the operational life of the bridge are reported. The results are consistent with recent laboratory observations that clearly indicate the importance of adequate alkalinity (pH buffering capacity) reserves to ensure durable reinforcement in concrete structures.
|
|
|
2017 |
Petersen RB, Melchers RE, 'Model for the long-term corrosion of cast iron pipes buried in soil', Life-Cycle of Engineering Systems: Emphasis on Sustainable Civil Infrastructure - 5th International Symposium on Life-Cycle Engineering, IALCCE 2016, Delft, The Netherlands (2017) [E1]
|
|
|
2017 |
Cartwright B, Melchers R, Aksu S, Magoga T, Song CM, McGuckin D, Renilson M, 'Structural integrity of maritime platforms', RINA, Royal Institution of Naval Architects - PACIFIC 2017 International Maritime Conference (2017)
© 2017 Royal Institution of Naval Architects. All rights reserved. Maritime assets are major investments. Their effective management is a very important factor in not only optimis... [more]
© 2017 Royal Institution of Naval Architects. All rights reserved. Maritime assets are major investments. Their effective management is a very important factor in not only optimising asset availability, effective lifetime, and functionality, but also reducing downtime for repairs. This paper presents a project that aims to develop an improved understanding of the structural degradation of naval and other vessels. Using an in-service ship as the study platform, structural degradation due to corrosion and fatigue within a representative environment is considered. Seaway loads, based on the operational profile of the ship, are applied to a finite element model to obtain the global and localised structural responses. Thus, stress-critical areas can be identified. Smoothed Particle Hydrodynamics is employed to model the fluid-structure interactions. Further, observational and experimental corrosion data is included to estimate the load-bearing capacity, the remaining safety margin, and the remaining service-life at different stages of the life-cycle of the ship.
|
|
|
2017 |
Wells T, Melchers RE, 'Modelling the life-cycle of concrete gravity sewers subject to microbial corrosion', Life-Cycle of Engineering Systems: Emphasis on Sustainable Civil Infrastructure - 5th International Symposium on Life-Cycle Engineering, IALCCE 2016, Delft, The Netherlands (2017) [E1]
|
|
|
2017 |
Chaves IA, Melchers RE, 'Microstructural effect on the marine corrosion of low-carbon steel weldments', Mechanics of Structures and Materials: Advancements and Challenges - Proceedings of the 24th Australasian Conference on the Mechanics of Structures and Materials, ACMSM24 2016, Perth, Australia (2017) [E1]
|
|
|
2017 |
Melchers RE, 'Developing realistic deterioration models', Life-Cycle of Engineering Systems: Emphasis on Sustainable Civil Infrastructure - 5th International Symposium on Life-Cycle Engineering, IALCCE 2016, Delft, The Netherlands (2017) [E1]
|
|
|
2017 |
Melchers RE, 'Physical, chemical and microbiological processes in the long term corrosion of steel and cast iron infrastructure', Mechanics of Structures and Materials: Advancements and Challenges - Proceedings of the 24th Australasian Conference on the Mechanics of Structures and Materials, ACMSM24 2016, Perth, Australia (2017) [E1] |
|
|
2017 |
Cartwright B, Melchers R, Aksu S, Magoga T, Song CM, McGuckin D, Renilson M, 'Structural integrity of maritime platforms', RINA, Royal Institution of Naval Architects - PACIFIC 2017 International Maritime Conference (2017)
© 2017 Royal Institution of Naval Architects. All rights reserved. Maritime assets are major investments. Their effective management is a very important factor in not only optimis... [more]
© 2017 Royal Institution of Naval Architects. All rights reserved. Maritime assets are major investments. Their effective management is a very important factor in not only optimising asset availability, effective lifetime, and functionality, but also reducing downtime for repairs. This paper presents a project that aims to develop an improved understanding of the structural degradation of naval and other vessels. Using an in-service ship as the study platform, structural degradation due to corrosion and fatigue within a representative environment is considered. Seaway loads, based on the operational profile of the ship, are applied to a finite element model to obtain the global and localised structural responses. Thus, stress-critical areas can be identified. Smoothed Particle Hydrodynamics is employed to model the fluid-structure interactions. Further, observational and experimental corrosion data is included to estimate the load-bearing capacity, the remaining safety margin, and the remaining service-life at different stages of the life-cycle of the ship.
|
|
|
2017 |
Jardim Do Nascimento B, Chaves I, Masia M, Melchers R, 'Masonry brick veneer and cavity brick wall tie corrosion', Proceedings of the ACA Conference: Corrosion and Prevention 2017, Sydney, Australia (2017)
|
|
|
2017 |
Liang M, Chaves IA, Melchers RE, 'Long-Term Marine Pitting Corrosion of AlMgSi Aluminium Alloys', Corrosion and Prevention, Sydney, Australia (2017) [E1]
|
|
|
2017 |
Chernov BB, Chaves IA, Nugmanov AM, Melchers RE, 'Comparative Marine Immersion Corrosion of Ship Construction Steels Exposed in Arctic and Temperate Waters', Corrosion and Prevention 2017, Sydney, Australia (2017) [E1]
|
|
|
2017 |
Jeffrey R, Melchers RE, 'The effect of coastal seawater temperature on corrosion of steel with different carbon contents', Corrosion and Prevention 2017, Sydney, Australia (2017) [E1]
|
|
|
2017 |
Wells T, Melchers R, 'Findings of a 7 year field study of concrete sewer pipe corrosion', Corrosion and Prevention 2017, Sydney, Australia (2017) [E1] |
|
|
2017 |
Petersen RB, Melchers RE, 'The influence of soil moisture on the corrosion of mild steel in clays', Corrosion and Prevention 2017, Sydney, Australia (2017) [E1]
|
|
|
2017 |
Soltani Asadi Z, Melchers RE, 'Evaluation of the surface topography of corroded old cast iron pipes', Corrosion and Prevention 2017, Sydney, Australia (2017) [E1]
|
|
|
2017 |
Melchers RE, Jeffrey R, 'Corrosion of steels under low D.O. Concentration and elevated temperature', Corrosion and Prevention 2017, Sydney, Australia (2017) [E1]
|
|
|
2016 |
Melchers RE, Potts AE, Yaghin AL, 'Wear and corrosion of FPSO mooring chains', PRADS 2016 - Proceedings of the 13th International Symposium on PRActical Design of Ships and Other Floating Structures (2016)
The design rules for FPSO mooring chain are empirical, derived mainly from experience in North Sea operations. This paper reports on aspects of a major industry-sponsored investig... [more]
The design rules for FPSO mooring chain are empirical, derived mainly from experience in North Sea operations. This paper reports on aspects of a major industry-sponsored investigation to ascertain the adequacy of these rules for moorings in the Tropics and what new rules might be needed. The detailed outcomes of the project and the proposals for new design rules are still under discussion and embargo. However, an overview is given of the research program underpinning the results and specifically of the corrosion testing program and the full-scale wear-testing program. Also, in an associated but separately funded test program laboratory wear tests were conducted on scale-model chains. Some results from the model tests are described also.
|
|
|
2016 |
Mokhtari M, Melchers RE, 'Advanced numerical method for failure assessment of corroded steel pipes', Proceedings of the Twenty-sixth (2016) International Offshore and Polar Engineering Conference, Rhodes, Greece (2016) [E1]
|
|
|
2016 |
Melchers R, Chaves IA, Lotfollahi Yaghin A, 'Studies of Iter-link Cyclic Wear of Axially Loaded Mooring Chains', Proceedings of the Twelfth (2016) Pacific-Asia Offshore Mechanics Symposium, Gold Coast, QLD (2016) [E1]
|
|
|
2016 |
Petersen RB, Nicholas D, Melchers R, Chaves I, Davies S, 'Relationship between microstructure and elemental segregation to the long-term corrosion performance of cast iron water pipes', Corrosion and Prevention, Auckland, New Zealand (2016) [E1]
|
|
|
2016 |
Petersen RB, Melchers R, 'Predicting the corrosion of cast iron pipes', Proceedings of OzWater'16, Melbourne (2016) [E1] |
|
|
2016 |
Petersen RB, Melchers R, 'Factors involved in the long-term corrosion of buried cast iron', Proceedings of Corrosion and Prevention 2016, Auckland, New Zealand (2016) [E1]
|
|
|
2016 |
Melchers R, Petersen RB, 'Romanoff's soil corrosion data deconstructed', Proceedings of Corrosion and Prevention 2016, Auckland, New Zealand (2016) [E1]
|
|
|
2016 |
Melchers R, Chaves IA, 'A study of initiation and active reinforcement corrosion in conventional reinforced concrete', Proceedings of Corrosion and Prevention 2016, Auckland, New Zealand (2016) [E1]
|
|
|
2016 |
Jeffrey R, Melchers RE, 'Identification of bacterial types in various atmospheric corrosion sites using standard test kits', Proceedings of Corrosion and Prevention 2016, Auckland, New Zealand (2016) [E1]
|
|
|
2016 |
Melchers RE, Wang X, 'Extreme value analysis of carbon steel pitting corrosion under deoxygenated seawater', Proceedings of Corrosion and Prevention 2016, Auckland, New Zealand (2016) [E1] |
|
|
2016 |
Liang M, Chaves IA, Melchers R, 'Long-term pitting corrosion of 6060 aluminium alloy immersed in natural seawater', Proceedings of Corrosion and Prevention 2016, Auckland, New Zealand (2016) [E1]
|
|
|
2016 |
Wang X, Melchers RE, 'Long-term under-deposit corrosion of carbon steel pipelines under stagnant seawater', Proceedings of the Twenty-sixth (2016) International Offshore and Polar Engineering Conference, Rhodes, Greece (2016) [E1]
|
|
|
2016 |
Melchers RE, Ahammed M, 'Pitting corrosion of offshore water injection steel pipelines', Proceedings of the Twenty-sixth (2016) International Offshore and Polar Engineering Conference, Rhodes, Greece (2016) [E1]
|
|
|
2016 |
Jeffrey R, Melchers RE, 'The effect of aluminium alloying on the corrosion resistance of cast steel', European Corrosion Congress, EUROCORR 2016 (2016)
© 2016 Curran Associates Inc. All rights reserved. There is some evidence that the addition of small amount of aluminium can reduce the atmospheric corrosion of steel. However, sy... [more]
© 2016 Curran Associates Inc. All rights reserved. There is some evidence that the addition of small amount of aluminium can reduce the atmospheric corrosion of steel. However, systematic long-term investigations are lacking. There also appears to be no information about resistance of such alloys to marine immersion conditions. This paper reports on the marine environment corrosion performance of steel alloyed with aluminium additions of 0% (control), 2%, 4%, 6% and 8%. The cast steel was forged into billets and machined into coupons. Sets of coupons were exposed to three exposure conditions: (a) in temperate seawater for 1, 2 and 3 years, (b) submerged below the mud-line for 1,2 and 3 years and (c) exposed at two extremely severe atmospheric marine locations for 12 months. The results show that the increase in Al content reduced corrosion loss in submerged conditions from 10.5% after one year to 2.8% after 3 years. In the coastal atmosphere, corrosion loss dropped from 5.5% after one year with no Al addition to 1.2% with 8% Al alloying. The corrosion resistance in marine mud buried conditions was less favourable. Corrosion loss reduced from 4.4% after one year to 2.9% after 2 years but in some instance the addition of Al had minimal or no effect on corrosion resistance. These observations add to the body of knowledge regarding the effect of aluminium on long-term corrosion loss.
|
|
|
2016 |
Melchers RE, 'MIC of cast iron infrastructure', European Corrosion Congress, EUROCORR 2016 (2016)
© 2016 Curran Associates Inc. All rights reserved. Cast iron was a construction material widely used for major infrastructure from the mid-late 1800s. Many existing functioning ro... [more]
© 2016 Curran Associates Inc. All rights reserved. Cast iron was a construction material widely used for major infrastructure from the mid-late 1800s. Many existing functioning road and railway bridges still have cast iron piers supporting them but a question of increasing importance is the rate at which the piers are deteriorating and thus their structural safety and life expectancy. Similarly, much older water supply pipeline systems in most major cities include extensive lengths of cast iron pipe. Cast iron is a surprisingly durable material but has long been suspected of being prone to MIC in wet poorly aerated conditions. Despite much research on MIC no direct link appears to have been established between MIC of cast iron and bacteria. The present paper reports recent field investigations of 4 sets of cast iron bridge piers in tidal seawater conditions that showed good correlation between accelerated low water corrosion (ALWC) and nutrient content in the seawater, similarly to what was demonstrated recently for steel sheet piling in seawater harbours. In one case the nutrient pollution is is likely to have occurred many years ago and to have left its legacy in the pile corrosion profile. For cast iron water pipes, preliminary analysis has shown correlation between soil nitrate content and greater than expected long-term corrosion loss, for pipes up to 129 years old. In the case of soils, nitrates are possibly part of the soil structure, introduced by the nitrogen cycle, or the result of pollution such as from fertilizers.
|
|
|
2016 |
Chaves IA, Melchers RE, 'Predicting Long Term Mild-Steel Weld Capacity Loss due to Climate Change Influenced Marine Corrosion', IIW 2016 Proceedings, Melbourne (2016) [E1]
|
|
|
2015 |
Melchers RE, 'Bi-model character for copper alloy corrosion and implications for long-Term MIC', European Corrosion Congress, EUROCORR 2015 (2015)
The long-Term corrosion of copper and copper alloys, such as 90:10 Cu-Ni, is of interest for their use in domestic and industrial piping systems, marine, urban and industrial envi... [more]
The long-Term corrosion of copper and copper alloys, such as 90:10 Cu-Ni, is of interest for their use in domestic and industrial piping systems, marine, urban and industrial environments including atmospheric and also as part of the containment of nuclear wastes in deep geological repositories. The evolution of the mass loss and maximum pit depth with increased exposure time is reviewed using data previously published in the literature. That data is re-interpreted. It shows that the classical 'power law' is not an appropriate model for corrosion evolution with time. However the data mainly are more consistent with the bi-modal model previously shown to apply to steels of various types and also to aluminium and aluminium alloys. The reasons for this are proposed as the result of the corrosion process changing from initially predominantly rate-controlled by the cathodic oxygen reaction and the diffusion of oxygen through some of the layers of corrosion product to, in the longer term, rate- controlled by products and processes involved in cathodic hydrogen reduction and the dissociation of water. This can occur for copper alloys but not for pure copper. In both cases pitting is a crucial aspect for the changing nature of the corrosion process. This new interpretation has implications for prediction of long-Term corrosion from short-Term observations. It provides an explanation for the frustration noted in the copper corrosion literature for the inability to predict long-Term behaviour from short-Term and electrochemical testing. It permits examination and reconciliation of the well-known influence of water pollution in causing MIC and accelerated (mainly pitting) corrosion of important copper alloys such as 90:10 CuNi.
|
|
|
2015 |
Lee TM, Melchers RE, Beech IB, Potts AE, Kilner AA, 'Microbiologically Influenced Corrosion (MIC) of mooring systems: Diagnostic techniques to improve mooring integrity', 20th Offshore Symposium 2015: Future Offshore Technology and Sustained Reliability (2015)
Copyright 2015, The Society of Naval Architects and Marine Engineers. Microbiologically Influenced Corrosion (MIC) is the term used to describe corrosion where the presence and ac... [more]
Copyright 2015, The Society of Naval Architects and Marine Engineers. Microbiologically Influenced Corrosion (MIC) is the term used to describe corrosion where the presence and activity of microorganisms accelerates the corrosion rate or modifies the mechanism of corrosion. MIC is strongly associated with the high rates of localized pitting corrosion observed on moorings installed in some offshore fields, including fields in West Africa and South East Asia. Diagnosis of MIC in the field can be problematic, and is largely reliant on visual inspection and microbiological reactivity tests, techniques that are limited in their accuracy and reliability. As a result, other forms of corrosion and wear can be easily misdiagnosed as MIC, with potential negative consequences for the subsequent management of the integrity of the mooring system. This paper presents an overview of the most recent research regarding factors influencing rates of conventional corrosion and MIC (as determined within the SCORCH JIP). It describes recent advances in the application of functional genetic and chemical analysis techniques to diagnose MIC, improve understand of the biochemical processes causing MIC, and identify pathways to interrupt and mitigate MIC on mooring components.
|
|
|
2015 |
Melchers RE, 'Inter-relationship between physical-chemical processes and extreme value modelling', 12th International Conference on Applications of Statistics and Probability in Civil Engineering, ICASP 2015 (2015)
Of considerable interest in various industries such as aerospace is the longer term safety of aluminium alloy structures and the effect of deterioration. Corrosion of aluminium al... [more]
Of considerable interest in various industries such as aerospace is the longer term safety of aluminium alloy structures and the effect of deterioration. Corrosion of aluminium alloys occurs mainly as pitting for which uncertainty and variability issues usually have led to maximum pit depth being considered a random variable that is also a function of time. An extreme value distribution is fitted to the statistical data obtained from multiple observations. Usually, the selection of the most appropriate model is based on the claim that one or other distribution is a 'better fit' to the data. This classical approach takes no account of prior knowledge of the underlying physicochemical process(es) that drive pitting behaviour. A more sophisticated approach uses such prior understanding. Recently it was shown that the linear model implied by the 'pitting rate' is too simplistic. Instead, a bi-modal model better represents both mass-loss as a function of exposure period and the evolution of maximum pit depth with time. This leads directly the possibility that one distribution may not be suitable for the whole range of pit depth data. These concepts are illustrated with examples.
|
|
|
2015 |
Melchers RE, 'On the bi-modal long-term characteristic for metallic corrosion', Australasian Corrosion Association Annual Conference: Corrosion and Prevention 2015, ACA 2015 (2015) [E1]
The bi-modal characteristic of general or 'uniform' corrosion, or corrosion as measured by mass loss, as a function of exposure time now has been demonstrated extensivel... [more]
The bi-modal characteristic of general or 'uniform' corrosion, or corrosion as measured by mass loss, as a function of exposure time now has been demonstrated extensively for various steels including low alloy, chromium and weathering steels, cast irons and, more recently also for aluminium alloys and for copper alloys. Also, it usually is independent of the environment. Further, it also occurs for the trend in maximum pitting as a function of time. This wide applicability demands explanation. Previously it was argued that the bi-modal character is the result of a change, at the metal-environment interface, from predominantly oxygen-rich corrosion conditions to predominantly locally anoxic corrosion conditions. It was argued also that pitting plays an important role in this process. Herein these concepts are extended from accepted theory for pitting under nominally oxic conditions that, within pits, become anoxic and causes the pitting process to become autocatalytic but eventually to lead to cessation of pit depth growth. There are two key outcomes. The first is the observation that pits grow episodically, that is, they grow in depth to a given limit, grow sideways and possibly amalgamate or coalesce, leaving plateaus of corroded surface in which new pitting can occur. The cycle time for this is faster under already anoxic conditions than earlier when it takes time for anoxic conditions to develop. The second outcome is that mass loss as a function of time is a function both of the pit depth and thus the pitting process and the increase in the number of pits with time. A considerable body of observational evidence is available to support these mechanisms. There also are well-developed theories that already explain the component mechanisms.
|
|
|
2015 |
Rajabipour A, Melchers RE, 'Service life of pitted pipes subject to pressure fluctuations and hydrogen embrittlement', Australasian Corrosion Association Annual Conference: Corrosion and Prevention 2015, ACA 2015 (2015) [E1]
For estimating the likely service life of brittle material pipes with exterior corrosion pits and subject to hydrogen embrittlement crack propagation from the pits is of interest.... [more]
For estimating the likely service life of brittle material pipes with exterior corrosion pits and subject to hydrogen embrittlement crack propagation from the pits is of interest. Similarity of pattern of fatigue cracking from these pits under pressure fluctuations to that under monotonically increasing pressure is referred to. This similarity permits the effect of hydrogen on the cracking rate to be formulated. The depth of cracks initiated from surface pits is estimated as a function of pipe service time, based on the proposed formulation for Hydrogen-Assisted Fatigue Cracking.
|
|
|
2015 |
Chaves IA, Wilson LJ, Melchers RE, 'Influence of climate change on long-term marine corrosion prediction', Australasian Corrosion Association Annual Conference: Corrosion and Prevention 2015, ACA 2015 (2015) [E1]
Increasingly climate change, including the possible rise of seawater surface temperatures is causing some concern regarding the integrity of commercial and industrial structures i... [more]
Increasingly climate change, including the possible rise of seawater surface temperatures is causing some concern regarding the integrity of commercial and industrial structures in marine exposed environments. Structural integrity (serviceability and safety) may be compromised by the increased rates of corrosion reactions caused by increased average temperatures. Immersed structural systems also may be prone to microbiologically influenced corrosion. In this paper, three different extrapolation techniques are used to model expected corrosion loss. They are based on the same set of short-term empirical mass loss data for 1 year exposures. The results are compared with mass loss data obtained from steel piling exposed for 33 years. It is shown that the extrapolations from short term data can be very significantly in error compared with actual observations and with better modelling approaches. The effects of temperature increase and of increased microbiological influences are considered as part of the investigation.
|
|
|
2015 |
Jeffrey R, Melchers RE, 'Atmospheric corrosion of mild steel vertical prisms, rounds and flat coupons of different shape and size', Australasian Corrosion Association Annual Conference: Corrosion and Prevention 2015, ACA 2015 (2015) [E1]
Atmospheric corrosivity typically is determined by deploying flat coupons and measuring mass loss over a specific period (usually a year) and then deriving a material loss rate (t... [more]
Atmospheric corrosivity typically is determined by deploying flat coupons and measuring mass loss over a specific period (usually a year) and then deriving a material loss rate (typically expressed as microns/year). Usually mild steel but also zinc, copper and aluminium coupons have been used. The derived corrosion loss is used to gauge the susceptibility of infrastructure, such as bridges and buildings, to corrosion. Previously it was shown that slightly different corrosion rates are obtained with coupons of different sizes even under identical exposure environments. From a practical perspective the question arises what size and shape of coupon most accurately reflects corrosion to be expected on realistic steel infrastructure in corresponding environments. Results from previous and new exposure trials are compared to estimate the effect of coupon size over a two year exposure period. Also, the effect of shape and size of round and prismatic specimens is investigated. The results show that larger coupon surface areas yield lower corrosion losses. The latter are considered more relevant for accurate estimation of likely corrosion losses for infrastructure.
|
|
|
2015 |
Soltani Asadi Z, Melchers RE, 'Probabilistic modelling of pit area in corroded cast iron pipes', Australasian Corrosion Association Annual Conference: Corrosion and Prevention 2015, ACA 2015 (2015) [E1]
The deterioration of cement lined cast iron water mains such as used extensively in cities in Australia and many other cities world-wide has been observed to be mainly caused by e... [more]
The deterioration of cement lined cast iron water mains such as used extensively in cities in Australia and many other cities world-wide has been observed to be mainly caused by external pitting corrosion. Since the pipes are buried and thus cannot c be inspected visually, there is considerable uncertainty about their condition. Indirect inspection techniques also have a high degree of uncertainty. For these reasons there is interest in long-term asset management to develop realistic models for depth and area of pitting corrosion to aid estimation of the probability of failure of older pipes. Generally it is considered that the deepest pits are of most interest in relation to failure. However, pit area is another important factor, which is crucial for estimating the rate of leakage and for assessing the mechanical behaviour and failure probability of pipes. Previous studies usually have assumed that pit area is directly related to pit depth. The present study examines pit area data collected from several pipes that have experienced many years of service (up to 129 years) and describes the relationship between pit areas and pit depths.
|
|
|
2015 |
Petersen RB, Melchers RE, 'The bi-modal corrosion behaviour of ferrous metals buried in soil', Australasian Corrosion Association Annual Conference: Corrosion and Prevention 2015, ACA 2015 (2015) [E1]
Long-term corrosion loss data for a variety of metals, including ferrous metals, buried in soils were reported in Romanoff (1957) and have often been quoted in the literature. The... [more]
Long-term corrosion loss data for a variety of metals, including ferrous metals, buried in soils were reported in Romanoff (1957) and have often been quoted in the literature. There have been few investigations of the long-term trending of the data. Herein it is shown that the corrosion behaviour of ferrous metals buried in the ground follows a bi-modal trend with time. This trend is observed for a variety of ferrous metals in many different natural environments. Similar trends have been reported also for other exposure environments. Importantly, it indicates that the corrosion process changes over time. This is illustrated for corrosion mass loss and corrosion penetration for a variety of data sets drawn from Romanoff (1957).
|
|
|
2015 |
Melchers RE, 'Internal corrosion of parked steel oil pipelines', Australasian Corrosion Association Annual Conference: Corrosion and Prevention 2015, ACA 2015 (2015) [E1]
Internal corrosion of steel pipelines before use, or temporarily taken out of use, and 'parked' on the seafloor for some time (months) continues to be an issue for offsh... [more]
Internal corrosion of steel pipelines before use, or temporarily taken out of use, and 'parked' on the seafloor for some time (months) continues to be an issue for offshore operators. This is irrespective of whether the pipes are oil production or water injection pipelines. Most commonly, severe pitting corrosion is observed at the 6 o'clock position. The conventional wisdom is that this is the result of microbiologically influenced corrosion (MIC). Indeed high concentrations of various bacteria have been found in the rusts in these pipes. The usual response is dosing with biocides but such treatment has been found to be not always very effective. It also may have environmental consequences if released to the sea when the pipe is put back into service or is abandoned. This paper reviews the available open literature on this topic and compares with previous findings for the severe internal corrosion at the 6 o'clock position sometimes found for water injection pipelines. This earlier work shows that periods of stagnant conditions with deposition of rusts and other debris at the bottom of (near-) horizontal pipes is the most likely reason for the severe corrosion sometimes observed. MIC can contribute to that corrosion but is not necessarily the major influence. Much depends on water quality. It is proposed that there are considerable similarities in the corrosion behaviour of parked oil pipelines and water injection pipelines and that there are considerable avenues for further research and development.
|
|
|
2015 |
Wang X, Melchers RE, 'Corrosion of carbon steel under mixed deposits in simulated deoxygenated seawater environment', Australasian Corrosion Association Annual Conference: Corrosion and Prevention 2015, ACA 2015 (2015) [E1]
Injecting seawater (and other water) into oil reservoirs to promote the rates of production is widely used in the offshore oil and gas industry. This is done using carbon steel wa... [more]
Injecting seawater (and other water) into oil reservoirs to promote the rates of production is widely used in the offshore oil and gas industry. This is done using carbon steel water injection pipelines (WIPs) for which internal corrosion sometimes is a major problem. Field experience often shows severe corrosion at the bottom part of the pipelines. This is known as channelling corrosion, 6 o'clock corrosion or bottom of the line corrosion. Field observations also show the presence of deposits at the 6 o'clock position and evidence of bacterial activity and both under-deposit corrosion (UDC) and microbiologically influenced corrosion (MIC) usually are suspected. Some WIPs treated with nitrate show more severe channelling corrosion than those without nitrate addition. This is contradictory with the primary purpose of adding nitrate to try to suppress the metabolism of aggressive sulphate reducing bacteria (SRB) within the oil reservoir. To date, the mechanism of channelling corrosion is not fully understood. The present work reports an experimental pilot study of the corrosion of carbon steel specimens under mixed deposits and simulated deoxygenated seawater environment. The influence of the presence of deposits, the treatment of seawater by filtration and ultraviolet (UV) irradiation and the addition of nitrate were evaluated by exposing carbon steel specimens to different test environments. The steel specimens were recovered from experimental vessels after 180 days and 365 days of exposure. The surface topography changes of steel surfaces were examined by stereo microscopy. The development of pitting under different test environments and the relative contributions to the formation of channelling corrosion are discussed.
|
|
|
2015 |
Yaghin AL, Melchers RE, 'Wear of axially loaded chains in dry and wet conditions', Proceedings of the International Offshore and Polar Engineering Conference (2015) [E1]
Copyright © 2015 by the International Society of Offshore and Polar Engineers (ISOPE). The safety of mooring lines used for maritime floating structures is of considerable importa... [more]
Copyright © 2015 by the International Society of Offshore and Polar Engineers (ISOPE). The safety of mooring lines used for maritime floating structures is of considerable importance since they may be damaged by storm waves and by material deterioration. This paper considers chain wear and reports on results of a study on the effect of water on wear rate of chains. For this purpose, a specially-designed laboratory test rig was used to wear the surfaces of inter-link zones of chain sets under static axial load. The results show that tensile force has a significant but nonlinear effect on wear rate and that wet conditions reduce the wear rate to a considerable extent.
|
|
|
2015 |
Rosen J, Jayasinghe K, Potts A, Melchers R, Chaplin R, 'SCORCH JIP - Findings from investigations into mooring chain and wire rope corrosion in warm waters', Proceedings of the Annual Offshore Technology Conference (2015)
Copyright © (2015) by the Offshore Technology Conference All rights reserved. For years operators have reported accelerated rates of corrosion in wire rope and chain in warmer wat... [more]
Copyright © (2015) by the Offshore Technology Conference All rights reserved. For years operators have reported accelerated rates of corrosion in wire rope and chain in warmer waters. Mooring design codes specify corrosion endurance of these components predominantly based on experience from the colder waters of the North Sea. The scope of the SCORCH JIP was to investigate and characterize corrosion of steel chain and wire rope moorings for a wide range of operating Floating Production Units (FPUs) and Floating Production Storage and Offtake vessels (FPSOs) in warm waters. A database was compiled of detailed corrosion measurements of in-service and retired mooring chains and wire ropes from about 30 FPUs operating in warm waters off Asia, Africa and the Americas. A set of standardized procedures were developed for forensic examinations of retrieved chain and wire rope, including photogrammetry and laboratory measurements that allowed 3D reconstruction and statistical analysis of corroded surfaces. The database was complemented by destructive tensile tests of a number of samples in order to correlate the observed degradation with residual breaking load. The SCORCH JIP also investigated the impact of sea temperature, water velocity, depth and oxygenation, steel grade and chain and wire rope construction through over 750 sample and full-scale tests spanning 3.5 years at sites around Australia. Additional laboratory tests were conducted into Microbiologically Influenced Corrosion (MIC) and the combined effect of corrosion and wear of mooring chains. The SCORCH JIP has produced a series of findings with long-lasting implications for the industry, including detailed investigations of factors in corrosion such MIC, chain pitting, chain wear, wire rope blocking compound efficacy, and the effect of environmental and operating conditions. The SCORCH JIP has produced tabulated predictions for corrosion in varying temperatures, at positions in the mooring line and for nutrient levels that could encourage MIC. The predictions are underpinned by a large number of field experiments and results from operating FPUs, and are supplemented by detailed operational guidance and recommendations for maximizing mooring corrosion endurance.
|
|
|
2015 |
Dockrill B, Melchers R, Eliasson B, Linton S, Herron C, 'Structural risk assessment of corroding infrastructure', Australasian Corrosion Association Annual Conference: Corrosion and Prevention 2015, ACA 2015 (2015)
Structural risk is not the same as corrosion risk. Therefore once assessment of infrastructure confirms corrosion is active and the mechanism(s) of corrosion are understood then t... [more]
Structural risk is not the same as corrosion risk. Therefore once assessment of infrastructure confirms corrosion is active and the mechanism(s) of corrosion are understood then this does not necessarily indicate an unacceptable structural risk. Asset managers, infrastructure owners and stakeholders normally indicate a required service life requirement. An implicit requirement is meeting structural and other safety requirements as defined by Australian or other Standards. Maintenance and/or remedial work activities are only supported for the asset to achieve desired functionality, serviceability, safety, operational and commercial outcomes for its required service life. The paper explores the differences between structural and corrosion risk and how each of these risk types should be considered in the assessment, management and maintenance of infrastructure to meet required service life, structural safety and risk requirements. Some examples are used to illustrate this theme.
|
|
|
2015 |
Chaves IA, Melchers RE, 'Variability in Long-Term Corrosion of Mild Steel Tubular Sheet Piling', Proceedings of the Twenty-fifth (2015) International Ocean and Polar Engineering Conference, Hawaii, USA (2015) [E1]
|
|
|
2014 |
Fontaine E, Rosen J, Potts A, Ma KT, Melchers R, 'SCORCH JIP - Feedback on MIC and pitting corrosion from field recovered mooring chain links', Proceedings of the Annual Offshore Technology Conference (2014)
Copyright 2014, Offshore Technology Conference. Forensic investigations on severely corroded (pitted) chains recovered from the mooring systems of two FPUs in West Africa and Indo... [more]
Copyright 2014, Offshore Technology Conference. Forensic investigations on severely corroded (pitted) chains recovered from the mooring systems of two FPUs in West Africa and Indonesia are described. During the course of the SCORCH JIP, it became apparent that a similar phenomenon had been experienced by other JIP participants indicating that it may be a common problem deserving attention. The conclusion of the present investigation is that the large pits most likely can be attributed to Microbiologically Influenced Corrosion (MIC). Where pitting occurred, the pit depth growth rate was found in instances to be up to 10 times the uniform corrosion rate, with pits distributed approximately uniformly but randomly around the link and the bar circumference. Destructive tensile tests of the samples indicated residual strength that was at worst 25% below as-manufactured estimated As-new Breaking Load (ABL). The correlation of loss of strength with loss of metallic area due to uniform and pitting corrosion indicated that breaking load cannot be treated simplistically, and requires more sophisticated consideration of the pit geometry and its location with respect to areas of high stress within the link.
|
|
|
2014 |
Pape T, Melchers R, 'The chloride conundrum in concrete', Annual Conference of the Australasian Corrosion Association 2014: Corrosion and Prevention 2014 (2014)
The number of publications relating to the good performance of older chloride-contaminated reinforced or prestressed concrete structures continues to rise. This contradicts the ma... [more]
The number of publications relating to the good performance of older chloride-contaminated reinforced or prestressed concrete structures continues to rise. This contradicts the majority of corrosion literature concerning structural concrete, which has continuously promoted the negative effects of chlorides since the 1960's. Various standards and guidelines reflect this sentiment, specifying empirical chloride threshold limits that are linked to corrosion risk levels. These have been adopted by industry to inform maintenance and repair procedures. It has also extended to an underlying view that detrimental corrosion may initiate and progress, which may be an incorrect assumption. To address this interpretation, a brief review is provided on the historical development of ideas and research behind chloride-contaminated concrete and associated corrosion-risk, and the subsequent establishment of accepted chloride limits. Results from 2 recent investigations relating to chloride-contaminated concrete are also discussed. A summary discussion on the implications and applications of these findings concludes the paper. This paper identifies that whilst chlorides remain an important consideration in the corrosion process, greater caution is required when assessing structural concrete for corrosion risk based purely on published chloride limits.
|
|
|
2014 |
Wells PA, Melchers RE, 'Findings of a 4 year study of concrete sewer pipe corrosion', Annual Conference of the Australasian Corrosion Association 2014: Corrosion and Prevention 2014 (2014) [E1]
Microbial induced corrosion (MIC) of reinforced concrete sewer piping and manholes is a significant issue in Australia and overseas costing water authorities hundreds of millions ... [more]
Microbial induced corrosion (MIC) of reinforced concrete sewer piping and manholes is a significant issue in Australia and overseas costing water authorities hundreds of millions of dollars annually. It is anticipated that as the country's sewer infrastructure ages the problem will become more severe. Over the last 4 years an ARC and industry funded research project has been undertaken with the aim of building a mathematical model to predict the corrosion of concrete as a function of exposure time and environmental and operational conditions. After almost 4 years of field trials in Sydney, Melbourne and Perth sewers a detailed understanding of the evolution of the corrosion process has emerged and a phenomenological model has been developed. The present paper describes the study findings and their implication for pipe service life prediction.
|
|
|
2014 |
Asadi ZS, Melchers RE, 'STatistical modelling for pitting corrosion of cast iron pipelineS', Annual Conference of the Australasian Corrosion Association 2014: Corrosion and Prevention 2014 (2014) [E1]
External corrosion is the main reason of the deterioration of cast iron water main in the Australia Water Industry. Prediction of the life time and the maximum pit depth which cau... [more]
External corrosion is the main reason of the deterioration of cast iron water main in the Australia Water Industry. Prediction of the life time and the maximum pit depth which causes failure can help to reduce the cost of water system maintenance. Due to the complexities of the mechanism of pitting as well as existence of numerous uncertainties, none of the conventional electrochemical approaches is capable of accurate prediction of pipe lifetime. This study, therefore, aims at investigating the maximum pit depth based on the probabilistic theory in order to assist with the prediction of the lifetime of pipelines. A probabilistic model based on the extreme value theory is suggested for this study. Real field data of pitting corrosion of a series of old underground pipelines have been gathered from some sites in Australia. Although Gumbel distribution has been widely employed for extrapolation of maximum pit depth of pipelines, analysis of these real data indicates that the variability of maximum pit depth in long- Term exposure fits the Frechet extreme value distribution. Moreover, results of this study show that for cases whose ages have been 30-50 years the maximum pit depth tends to follow one Frechet distribution, while two subsequent Frechet curves have been observed in the probabilistic distributions of data of cases which are older than 50-60 years.
|
|
|
2014 |
Wang X, Melchers RE, 'Laboratory study of under-deposit corrosion of steel pipelines in seawater environment', Annual Conference of the Australasian Corrosion Association 2014: Corrosion and Prevention 2014 (2014) [E1]
Water injection is a practical and widely employed method to promote production for oil industry especially for mature oil reservoirs. For this seawater, aquifer water and produce... [more]
Water injection is a practical and widely employed method to promote production for oil industry especially for mature oil reservoirs. For this seawater, aquifer water and produced water (water recovered from crude oil) are most commonly used. Typically the water injection pipelines (WIP) are carbon steel and are not cathodically protected. The potential for pipeline failure caused by internal corrosion is an on-going concern for the industry. Corrosion mitigation methods include deoxygenation, corrosion inhibitors, biocides, and pigging. The most serious corrosion problem is channelling corrosion, known also as 6 o'clock corrosion or bottom of line corrosion, although it does not occur in all pipelines, for reasons not fully understood. It shows as aggressive corrosion at the bottom part of pipelines and is much more severe than corrosion elsewhere in WIPs. Recent assessment and monitoring of several water injection pipelines from the North Sea continental shelf obtained either by intelligent pigging tools or on-site bio-coupons has indicated that microbiologically influenced corrosion (MIC) and under-deposit corrosion are likely to be involved in channelling corrosion. Despite occasional industrial reports and conference papers, the comprehensive interpretation of this type of corrosion is still limited. The present paper outlines an experimental pilot study of under-deposit corrosion of mild steel model pipeline coupons exposed to deoxygenated natural seawater in simulated field conditions. Identical test rigs and different test scenarios were established to ascertain the influence of the presence of deposits, of water quality, surface roughness and nitrate addition. SEM observations of changes in surface topography for the first set of samples after 12 days exposure are reported. The paper also discusses the potential reasons of the formation process of channelling corrosion in water injection pipelines and the effect of early stage corrosion for long-term trends.
|
|
|
2014 |
Jeffrey R, Melchers RE, 'Five year observations of corrosion losses for steels at a severe marine atmospheric site', Annual Conference of the Australasian Corrosion Association 2014: Corrosion and Prevention 2014 (2014) [E1]
Comprehensive new data for the effects of orientation, height and bold exposure versus shielding effects and detailed chronological observations and variability data for nominally... [more]
Comprehensive new data for the effects of orientation, height and bold exposure versus shielding effects and detailed chronological observations and variability data for nominally identical exposures of mild steel coupons all exposed at one site is presented. Previous investigations have been reported only for different sites and this raises difficulties in making comparisons and deductions. The present results have been obtained under the one local climatic regime for all coupons, thus providing a much more controlled environment within which to compare various effects. The present paper deals with the five-year results and compares these with information available in the literature. After three years most of the boldly exposed double-sided coupons had completely corroded but many single-sided coupons remained viable. The difference in corrosion behaviour between individual coupons exposed at different heights and vertical continuous single strips of steel is described. Moreover, the difference in corrosion losses for a continuous strip and for a series of coupons oriented in different directions is described. Furthermore, variability of nominally identically exposed coupons is reported.
|
|
|
2014 |
Melchers RE, 'Trends in long-term corrosion of aluminium alloys in marine, industrial and urban environments', Annual Conference of the Australasian Corrosion Association 2014: Corrosion and Prevention 2014 (2014) [E1]
Aluminium alloys have excellent corrosion resistance including in seawater and marine conditions. Herein a wide range of literature data, including in-situ immersion, tidal, coast... [more]
Aluminium alloys have excellent corrosion resistance including in seawater and marine conditions. Herein a wide range of literature data, including in-situ immersion, tidal, coastal atmospheric and industrial exposures is examined. It is shown that while the classical power-law has been assumed, widely, to be valid as a model for the progression of corrosion, in the longer term corrosion of aluminium alloys is nearly always more consistent with the bi-modal model previously proposed only for the corrosion behaviour of steels in seawater and marine conditions, including in the atmosphere. Although aluminium alloys tend to pit rather than to corrode 'uniformly', the bi-modal trend applies irrespectively of whether mass loss, loss of tensile strength or the deepest pits are considered. It is proposed the bi-modal characteristic results from the accumulation of corrosion products causing localised anoxic conditions. These permit a change from predominantly cathodic oxygen reduction to hydrogen ion reduction under anoxic autocatalytic conditions within pits. This mechanism is consistent with established theory for pitting corrosion in aluminium, such as proposed many years ago by Wranglen. It is shown that maximum pit depths for very deep pits tend to follow the Frechet rather than the Gumbel Extreme Value distribution. This is consistent with what has been observed previously for steels.
|
|
|
2014 |
Jeffrey R, Melchers RE, 'A comparison of corrosion profiles of steel strips, coupons and chains', Annual Conference of the Australasian Corrosion Association 2014: Corrosion and Prevention 2014 (2014) [E1]
Corrosion profiles for coupons and for single strips have been published previously and tend to show a distinct difference between the two. Corrosion of a continuous strip usually... [more]
Corrosion profiles for coupons and for single strips have been published previously and tend to show a distinct difference between the two. Corrosion of a continuous strip usually results in a flatter profile than that obtained for a set of individual coupons. Herein these results are compared with the corrosion of chain links in chains exposed through the tidal zone. Steel chains are used extensively in the marine industry and are subject to the same corrosive effects as other marine steel infrastructure. The matter of interest is whether chain links act as individual coupons or form part of a single strip as in electrically connected links of a chain. If the corrosion profile is similar to that of coupons, individual links will act as isolated cathode/anode couples and will corrode faster in the tidal zone than if the corrosion loss is spread over the entire length of the chain. The present paper presents corrosion profiles derived from lengths of nominally 10 mm diameter steel chains exposed at three geographical locations and compares these profiles to profiles obtained from single strips and sets of individual coupons exposed at the same or similar locations.
|
|
|
2014 |
Melchers RE, Chaves IA, 'New results for the corrosion of reinforcement in marine environments', Annual Conference of the Australasian Corrosion Association 2014: Corrosion and Prevention 2014 (2014) [E1]
The apparently premature corrosion of steel reinforcement in reinforced concrete structures exposed to marine environments continues to be a matter of concern in practice despite ... [more]
The apparently premature corrosion of steel reinforcement in reinforced concrete structures exposed to marine environments continues to be a matter of concern in practice despite decades of research effort and much research funding expenditure and despite much practical experience. Herein results are reported of a long-term (10 year) study of the influence of alkalis on the corrosion initiation and progression of 6mm diam. reinforcing bars centrally embedded in 40x40x160mm concrete specimens. These were made with seawater as mixing water and with a variety of mix proportions including some with added alkalis. All were equally well compacted by vibration. After 10 years continuous exposure in a fog-room only a limited amount of corrosion initiation was observed. These results are in stark contrast with those reported in the famous paper by Shalon & Raphael (1959) who found serious corrosion of reinforcement after only 1-2 years exposure for all mixes. It is shown herein that the corrosion loss trends in those tests are similar to those of steel exposed directly to seawater. This indicates that in the 1959 tests the concrete provided little protection against reinforcement corrosion. The reasons for this are considered herein and the practical implications discussed.
|
|
|
2014 |
Petersen RB, Melchers RE, 'Long term corrosion of buried cast iron pipes in native soils', Annual Conference of the Australasian Corrosion Association 2014: Corrosion and Prevention 2014 (2014) [E1]
The corrosion of old buried cast iron water mains is a problem for the Australian Water Industry. To better manage their assets the industry requires a way of predicting the remai... [more]
The corrosion of old buried cast iron water mains is a problem for the Australian Water Industry. To better manage their assets the industry requires a way of predicting the remaining service life of their pipes. In order to do this a predictive model of long-term corrosion loss with time is required. This paper describes ongoing work being conducted at The University of Newcastle to develop corrosion loss models for cast iron pipes in soils, as a function of exposure time and soil environment. A preliminary corrosion model was calibrated in a previous work, using a limited set of data collected from recent field work. This data base was extended in the current work by including data (of maximum pit depth and some soil properties) from historical condition assessments within the Hunter Water network. Previous studies by the authors (and others) indicate the significance of soil moisture content on the long-term corrosion loss and rate. At most sites soil moisture was only measured at a single point in time (or not at all), so the long-term average value of soil moisture (required for model calibration) was uncertain. To better estimate the average long-term soil moisture content, a simple climate-soil moisture model was developed. This paper presents the collected field data, describes the method for estimating long-term moisture content and presents the updated model calibration based on the additional data.
|
|
|
2014 |
Rosen J, Potts AE, Melchers RE, 'MIC and pitting corrosion on field recovered mooring chain links', Annual Conference of the Australasian Corrosion Association 2014: Corrosion and Prevention 2014 (2014) [E1]
Forensic investigations were performed on chain links recovered from two FSO mooring systems in West Africa and Indonesia. Although these links were in tropical seawater for only ... [more]
Forensic investigations were performed on chain links recovered from two FSO mooring systems in West Africa and Indonesia. Although these links were in tropical seawater for only 7 years, they experienced extremely severe pitting corrosion not previously seen in any available records. The material presented has direct application to ensuring the integrity of mooring systems as it provides insight into the mechanical behaviour of highly corroded chain links, statistics of the observed corrosion rates in these locations and guidelines for examining chain links. Corrosion on the surface of the links was mapped using 3D photogrammetry. The observed long-term corrosion rate is significantly higher than the average corrosion rate of 0.4 mm/year given in API RP-2SK. Analysis of the elementary composition of the rusts indicates that the large pits observed were most likely associated with Microbiologically Influenced Corrosion (MIC). The obtained results represent a breakthrough in the field of corrosion of mooring chains deployed in tropical seawater, corroborating the latest models that have been developed taking into account MIC. This work was conducted under the scope of the SCORCH JIP which involves ExxonMobil, Chevron, BP, Total, Shell, BHP Billiton, ConocoPhillips, Petrobras, Statoil, BSEE, DNV, ABS, Bureau Veritas, INPEX, SOFEC, InterMoor, KBR, SBM, Franklin Offshore, Vicinay Cadenas, Bridon, Arcelormittal, Arrium and Vryhof Anchors.
|
|
|
2014 |
Chaves IA, Jeffrey R, Melchers RE, 'The effect of cleaning procedures on corrosion coupon surface topography', Australasian Corrosion Association, Darwin - Australia (2014) [E1]
|
|
|
2014 |
Melchers RE, Pape TM, Chaves IA, 'The long-term durability of reinforced concrete structures exposed to aggressive marine environments', Proceedings of the First International Conference on Infrastructure Failures and Consequences, Melbourne - Australia (2014) [E1]
|
|
|
2013 |
Melchers RE, Jeffrey R, 'Atmospheric Corrosion Of Mild Steel Vertical Prisms Of Different Plan Shape', Corrosion and Prevention 2013, Brisbane (2013) [E1]
|
|
|
2013 |
Jeffrey R, Melchers RE, 'The effect of aluminium allying on the corrosion resistance of cast steel', Corrosion and Prevention 2013 Proceedings, Brisbane (2013) [E1]
|
|
|
2013 |
Petersen RB, Dafter M, Melchers RE, 'Modelling The Long-Term Corrosion Of Cast Iron Pipes', Corrosion and Prevention 2013 Proceedings, Brisbane (2013) [E1] |
|
|
2013 |
Pape TM, Melchers RE, 'A Study Of Reinforced Concrete Piles From The Hornibrook Highway Bridge (1935-2011)', Corrosion and Prevention 2013 Proceedings, Brisbane (2013) [E1] |
|
|
2013 |
Melchers RE, Herron C, Emslie R, 'Variability In Long-Term Corrosion Of Cast Iron Bridge Piers', Corrosion and Prevention 2013 Proceedings, Brisbane (2013) [E1] |
|
|
2013 |
Chaves IA, Melchers RE, 'Reliability Based Evaluation Of Commonly Applied Corrosion Mitigation Techniques', Corrosion and Prevention 2013 Proceedings, Brisbane (2013) [E1]
|
|
|
2013 |
Melchers RE, Comanescu I, 'Influence Of MIC On Corrosion Of Oil Field Water Injection Pipelines', Corrosion and Prevention 2013 Proceedings, Brisbane (2013) [E1] |
|
|
2013 |
Petersen RB, Dafter M, Melchers RE, 'Long-term corrosion of buried cast iron water mains: field data collection and model calibration', LESAM 2013 Strategic Asset Management of Water and Wastewater Infrastructure, Sydney Australia (2013) [E2] |
|
|
2013 |
Chaves IA, Melchers RE, 'Probabilistic pitting corrosion risk assessment of welded offshore steel pipelines', Proceedings of the Twenty-third International Offshore and Polar Engineering Conference, Anchorage, AK (2013) [E1]
|
|
|
2013 |
Melchers RE, 'Mechanism for Debonding of Internal Pipeline Lining in De-aerated Environments', Proceedings of the 23rd International Offshore and Polar Engineering Conference (ISOPE 2013), Volume 4, Anchorage, AL (2013) [E1] |
|
|
2013 |
Melchers RE, Herron C, Emslie R, 'Variability in long-term corrosion of cast iron bridge piers', Annual Conference of the Australasian Corrosion Association 2013: Corrosion and Prevention 2013 (2013)
Copyright © 2013 by the Australasian Corrosion Association. In 2010 the disused railway bridge at St Lawrence on the Queensland Pacific Ocean coast was demolished after 90 years s... [more]
Copyright © 2013 by the Australasian Corrosion Association. In 2010 the disused railway bridge at St Lawrence on the Queensland Pacific Ocean coast was demolished after 90 years service across the St Lawrence Creek, Queensland, some 6 km inland from the Pacific Ocean and subject large (up to 9 m) seawater tidal movements. Detailed examination of samples about 300×300 mm square and larger cut from several of the bridge piers at various elevations showed corrosion loss varying on average between 2-3 mm for the immersion and tidal exposure zones. This is remarkably little for such aggressive environment and for such long duration of exposure. There was negligible corrosion in the atmospheric zone. The multiple samples allowed statistical analysis of the variability of corrosion losses at different elevations. The statistical results are unique for such long-term exposures and are of major importance for structural reliability analyses of similar old bridges. Also, the corrosion loss results were compared with results reported in the literature for which the longest period of observation is only a few years. Observations show that cast iron is not free from localized corrosion and pitting as sometimes assumed. The corrosion loss results were compared to patterns previously observed for corrosion of steel through the tidal zone. A pattern consistent with so-called accelerated low water corrosion was observed, suggesting that at some period of time in the history of the bridge the tidal seawaters suffered some degree of water pollution.
|
|
|
2013 |
Comanescu I, Taxén C, Melchers RE, 'Possible influence of microorganisms on the patterns of corrosion seen in water injection pipelines', NACE Corrosion Conference and Expo 2013, Orlando, FL (2013) [E1]
|
|
|
2013 |
Melchers RE, Comanescu I, 'Influence of MIC on corrosion of oil field water injection pipelines', Annual Conference of the Australasian Corrosion Association 2013: Corrosion and Prevention 2013 (2013)
Copyright © 2013 by the Australasian Corrosion Association. Water injection or water flooding is widely used as a secondary recovery method to increase the production of oil usual... [more]
Copyright © 2013 by the Australasian Corrosion Association. Water injection or water flooding is widely used as a secondary recovery method to increase the production of oil usually from mature oil wells. It requires the injection of water into the reservoir, typically using carbon steel pipelines. Their corrosion is a major issue for the oil and gas industry, involving high costs of periodic chemical treatment, including biocides, oxygen scavengers, corrosion and scale inhibitors, and pipeline pigging. There is also the high potential cost of premature failure of the pipelines relative to life-time predictions, and the associated potential for unpredicted costs and major environmental implications should the pipeline fail. The present paper presents a review of a pilot study supported by the oil industry and the European Community that aimed to improve understanding of the corrosion behaviour of these pipelines. It draws on data and observations for the long-term corrosion, water quality, intelligent pigging records and microbiological testing to gain a better understanding why some pipelines suffer mild corrosion yet others, apparently similar, are prone to highly aggressive channelling corrosion. Herein the documented experience of several pipelines is reviewed. Observation data taken into consideration include pigging operation information, composition of corrosion products and their amount, corrosion rates and pipe geometry, identified biological consortia, water chemistry and process parameters. Also, the distribution of corrosion along the pipeline as well as the localization of corrosion attack is noted. Preliminary correlations between and conclusions about observed corrosion, operational conditions and service history are made. A Joint Industry research project currently is being arranged by the offshore oil industry to extend this work.
|
|
|
2013 |
Jeffrey R, Melchers RE, 'Atmospheric corrosion of mild steel vertical prisms of different plan shape', Annual Conference of the Australasian Corrosion Association 2013: Corrosion and Prevention 2013 (2013)
Copyright © 2013 by the Australasian Corrosion Association. Atmospheric corrosion tests of mild steel have employed thin flat steel panels of various sizes, with low edge to main ... [more]
Copyright © 2013 by the Australasian Corrosion Association. Atmospheric corrosion tests of mild steel have employed thin flat steel panels of various sizes, with low edge to main surface ratios. The corrosion loss results relate well to the corrosion of flat steel products and surfaces. The few results reported for circular coupons such as wires showed corrosion losses higher than for flat plates (Jeffrey et al). Herein new observations are reported for the development of rusts, delamination of rusts and of atmospheric corrosion losses for mild steel square, hexagonal and circular prisms exposed in the vertical orientation at Belmont Beach for up to 3 years. The corrosion loss results are compared to previously reported results for flat plate coupons at the same site. In general, smaller samples, including the flat coupons, corroded much more than larger samples. For the smaller prisms rusts delaminated within 12 months or less whereas delamination was not observed for the larger samples. It is proposed that this the result of radial or equivalent cracking permitting higher rates of oxygen diffusion to the corrosion interface.
|
|
|
2013 |
Petersen RB, Dafter M, Melchers RE, 'Modelling the long-term corrosion of cast iron pipes', Annual Conference of the Australasian Corrosion Association 2013: Corrosion and Prevention 2013 (2013)
Copyright © 2013 by the Australasian Corrosion Association. The external corrosion of buried cast iron water mains is a significant problem for the Australian Water Industry. To i... [more]
Copyright © 2013 by the Australasian Corrosion Association. The external corrosion of buried cast iron water mains is a significant problem for the Australian Water Industry. To improve maintenance and replacement strategies for these mains the industry requires a method to estimate their remaining service lives. Predictions of long-term corrosion losses, pit depths and pitting extents are therefore required. A conceptual model for the prediction of long-term corrosion has been developed and the external soil conditions influencing corrosion were identified in a previous study. To calibrate the model, long-term data of corrosion (average loss and maximum penetration) and associated soil parameters for pipes in service is required. Field data has been collected at 18 condition assessment sites and two pipe replacement sites within Hunter Water Corporation's network. This paper presents the field observations and measurements taken from these sites, the model calibration procedure and results of the calibration. The results show that the long-term maximum corrosion penetration increases with increasing soil wetness (measured using degree of saturation) over the observed range of degree of saturation (0.5 to 0.86). The initial model calibration produced model parameters for cast iron pipes buried at standard depths in relatively homogeneous, low-permeability, soils with degrees of saturation equal to 0.57, 0.66, and 0.76.
|
|
|
2013 |
Pape TM, Melchers RE, 'A study of reinforced concrete piles from the hornibrook highway bridge (1935-2011)', Annual Conference of the Australasian Corrosion Association 2013: Corrosion and Prevention 2013 (2013)
Copyright © 2013 by the Australasian Corrosion Association. The Hornibrook Highway Bridge was a 2684m long timber and concrete bridge spanning across Bramble Bay north of Brisbane... [more]
Copyright © 2013 by the Australasian Corrosion Association. The Hornibrook Highway Bridge was a 2684m long timber and concrete bridge spanning across Bramble Bay north of Brisbane, Queensland. Completed in 1935, it was the longest road viaduct across water in Australia at the time. It was demolished in 2011 after 76 years of service due to substantial timber degradation and the deterioration of the concrete due to corrosion. A number of piles were salvaged from demolition and studied by the University of Newcastle. This paper outlines some of the findings from this investigation. The piles and reinforcing bars were in relatively good condition with minimal cross-sectional area losses despite the age of the bridge and exposure to an aggressive marine environment. An exception was the severe corrosion of a bar in one pile with no obvious external visual evidence. A summary of petrographic and XRD analyses, and carbonation profiles are also presented and discussed.
|
|
|
2013 |
Jeffrey R, Melchers RE, 'The effect of aluminium alloying on the corrosion resistance of cast steel', Annual Conference of the Australasian Corrosion Association 2013: Corrosion and Prevention 2013 (2013)
Copyright © 2013 by the Australasian Corrosion Association. There is some evidence that the addition of small amount of aluminium can reduce the atmospheric corrosion of steel. Ho... [more]
Copyright © 2013 by the Australasian Corrosion Association. There is some evidence that the addition of small amount of aluminium can reduce the atmospheric corrosion of steel. However, systematic long-term investigations are lacking. There also appears to be no information about resistance of such alloys to marine immersion conditions. This paper reports on the marine environment corrosion performance of steel alloyed with aluminium additions of 0% (control), 2%, 4%, 6% and 8%. The cast steel was forged into billets and machined into coupons. Sets of coupons were exposed to three exposure conditions: (a) in temperate seawater for 1, 2 and 3 years, (b) submerged below the mud-line for 1, 2 and 3 years and (c) exposed at two extremely severe atmospheric marine locations for 12 months. The results show that the increase in Al content reduced corrosion loss in submerged conditions from 10.5% after one year to 2.8% after 3 years. In the coastal atmosphere, corrosion loss dropped from 5.5% after one year with no Al addition to 1.2% with 8% Al alloying. The corrosion resistance in marine mud buried conditions was less favourable. Corrosion loss reduced from 4.4% after one year to 2.9% after 2 years but in some instance the addition of Al had minimal or no effect on corrosion resistance. These observations add to the body of knowledge regarding the effect of aluminium on long-term corrosion loss.
|
|
|
2013 |
Chaves IA, Melchers RE, 'Reliability analysis of steel pipeline welds subjected to long-term seawater exposure', From Materials to Structures: Advancement through Innovation, Sydney, NSW (2013) [E1]
|
|
|
2013 |
Pape TM, Melchers RE, 'Structural performance of 45 year old corroded prestressed concrete beams', From Materials to Structures: Advances through Innovation. Proceedings of the 22nd Australasian Conference on the Mechanics of Structures and Materials, ACMSM 22, Sydney, Australia (2013) [E1] |
|
|
2012 |
Jeffrey RJ, Melchers RE, 'The effect of microbiological involvement on the topography of corroding mild steel in coastal seawater', Book of Abstracts. Eurocorr 2012, Istanbul, Turkey (2012) [E2]
|
|
|
2012 |
Chaves IA, Melchers RE, 'Reliability analysis of long term pitting corrosion of welded marine steel pipelines', Corrosion Management for a Sustainable World: Transport, Energy, Mining, Life Extension and Modelling, Melbourne, Australia (2012) [E1]
|
|
|
2012 |
Melchers RE, 'The relative influence of microbiological and abiotic processes in modelling longer-term marine corrosion of steel', Eurocorr 2012. The European Corrosion Congress, Istanbul, Turkey (2012) [E2] |
|
|
2012 |
Comanescu I, Melchers RE, 'Correlation between MIC and water quality, pigging frequency and biocide dosing in oil field water injection pipelines', Eurocorr 2012. The European Corrosion Congress, Istanbul, Turkey (2012) [E2] |
|
|
2012 |
Taxen C, Comanescu I, Melchers RE, 'Framework model for under deposit corrosion in water injection pipelines', Eurocorr 2012. The European Corrosion Congress, Istanbul, Turkey (2012) [E2] |
|
|
2012 |
Melchers RE, Jeffrey RJ, Fontaine E, 'Corrosion and the structural safety of FPSO mooring systems in Tropical waters', Proceedings of the Australasian Structural Engineering Conference 2012, Perth, WA (2012) [E1]
|
|
|
2012 |
Melchers RE, Pape TM, 'The durability of reinforced concrete structures in marine environments', Proceedings Australasian Structural Engineering Conference 2012, Perth, WA (2012)
|
|
|
2012 |
Comanescu I, Taxen C, Melchers RE, 'Assessment of MIC in carbon steel water injection pipelines', SPE International Conference and Exhibition on Oilfield Corrosion 2012, Aberdeen, UK (2012) [E2]
|
|
|
2012 |
Fontaine E, Potts A, Consulting A, Ma K-T, Company CT, Arredondo A, et al., 'SCORCH JIP: Examination and testing of severely-corroded mooring chains from West Africa', Proceedings of the Annual Offshore Technology Conference 2012, Houston, Texas (2012) [E2]
|
|
|
2012 |
Jeffrey RJ, Melchers RE, 'The changing composition of the corrosion products of mild steel in severe marine atmospheres', Annual Conference of the Australasian Corrosion Association 2012, melbourne, australia (2012) [E1]
|
|
|
2012 |
Melchers RE, 'Long-term corrosion of grey cast iron in marine environments', Annual Conference of the Australasian Corrosion Association 2012, melbourne, australia (2012) |
|
|
2012 |
Chaves IA, Melchers RE, 'External corrosion of carbon steel pipeline weld zones', Proceedings of the 22nd International Ocean and Polar Engineering Conference, Rhodes, Greece (2012) [E1]
|
|
|
2012 |
Fontaine E, Potts AE, Arredondo A, Melchers RE, Ma K-T, 'Investigation of severe corrosion of mooring chain in West Africa Waters', Proceedings of the Twenty-second (2012) International Offshore and Polar Engineering Conference, Rhodes, Greece (2012) [E1]
|
|
|
2012 |
Comanescu I, Melchers RE, Taxen C, 'Life time assessment of offshore water injection pipelines as a function of microbiologically influenced corrosion', Proceedings of the Twenty-second (2012) International Offshore and Polar Engineering Conference, Rhodes, Greece (2012) [E1]
|
|
|
2012 |
Wells PA, Melchers RE, Joseph A, Bond P, Vitanage D, Bustamante H, et al., 'A collaborative investigation of microbial corrosion of concrete sewer pipe in Australia', Conference Proceedings. Oz Water '12. Australia's National Water Conference and Exhibition, Sydney, NSW (2012) [E1] |
|
|
2012 |
Melchers RE, 'Structural reliability estimation for steel structures affected by pitting corrosion', ISRERM2012: Reliability Engineering and Risk Management ISRERM2012, Yokohama, Japan (2012) [E1] |
|
|
2012 |
Jeffrey RJ, Melchers RE, 'The effect of increasing amounts of nutrient on the corrosion rate of mild steel', Corrosion & Prevention 2012, Melbourne, Australia (2012) [E1]
|
|
|
2012 |
Jeffrey RJ, Melchers RE, 'The effect coupon size for the determination of atmospheric corrosivity', Corrosion & Prevention 2012, Melbourne, Australia (2012) [E1]
|
|
|
2012 |
Stockert L, Haas M, Jeffrey RJ, Melchers RE, 'Electrochemical measurements and short-term-in-situ exposure testing', Corrosion & Prevention 2012, Melbourne, Australia (2012) [E1]
|
|
|
2012 |
Dafter MR, Melchers RE, Nicholas DM, 'Prediction of long term corrosion in soils using electrochemical tests', Corrosion & Prevention 2012, Melbourne, Australia (2012) [E1]
|
|
|
2012 |
Melchers RE, 'Long term corrosion of grey cast iron in marine environments', Corrosion Management for a Sustainable World: Transport, Energy, Mining, Life Extension and Modelling, Melbourne, Vic (2012) [E1] |
|
|
2012 |
Petersen RB, Melchers RE, 'Long-term corrosion of cast iron cement lined pipes', Corrosion Management for a Sustainable World: Transport, Energy, Mining, Life Extension and Modelling, Melbourne, Australia (2012) [E1]
|
|
|
2012 |
Potts AE, Fontaine E, Melchers R, 'Investigation of severe corrosion of mooring chain in west African waters', Annual Conference of the Australasian Corrosion Association 2012 (2012)
Recent detailed observations of the performance of mooring chains for a floating production unit in tropical West African waters have shown severe localized corrosion (pitting) of... [more]
Recent detailed observations of the performance of mooring chains for a floating production unit in tropical West African waters have shown severe localized corrosion (pitting) of the steel chain after only seven years of use. This paper describes the investigation of this phenomenon as part of the Joint Industry Paper (JIP) research program SCORCH (Seawater Corrosion of Rope and Chain) funded by the major oil companies, most Classification Societies and various offshore operators and manufacturers. It is shown that there is a high likelihood that the chain has been subjected to microbiology influenced corrosion (MIC) as a result of the elevated levels of water pollution in the operational area. However, despite the large localized loss of steel in corrosion pots, the breaking load shows only a relatively small reduction compared to the Minimum Breaking Load specified in design guidelines. Copyright © (2012) by the Australasian Corrosion Association.
|
|
|
2012 |
Melchers RE, 'Safety and reliability of FPSO mooring systems', 6th International ASRANet Conference for Integrating Structural Analysis, Risk and Reliability, London, UK (2012) [E2] |
|
|
2011 |
Melchers RE, 'Modelling long-term corrosion of mild steel in unpolluted fresh and sterile seawaters', 18th International Corrosion Congress 2011, Perth (2011) [E1]
|
|
|
2011 |
Chaves IA, Melchers RE, 'Long-term marine corrosion of welds on steel piling', 18th International Corrosion Congress 2011, Perth, WA (2011) [E1]
|
|
|
2011 |
Jeffrey RJ, Melchers RE, 'The effect of airborne nutrients on atmospheric corrosion', 18th International Corrosion Congress 2011, Perth, WA (2011) [E1]
|
|
|
2011 |
Pape TM, Melchers RE, 'A detailed case study of carbonation profiles in prestressed concrete beams from an aggressive marine environment', 18th International Corrosion Congress 2011, Perth, WA (2011) [E1]
|
|
|
2011 |
Wells PA, Melchers RE, 'Microbial corrosion of sewer pipe in Australia - Initial field results', 18th International Corrosion Congress 2011, Perth, WA (2011) [E1]
|
|
|
2011 |
Melchers RE, Jeffrey RJ, 'Deterioration mechanics - The competition between abiotic and biotic processes', Incorporating Sustainable Practice in Mechanics of Structures and Materials: Proceedings of the 21st Australian Conference on the Mechanics of Structures and Materials, Melbourne, VIC (2011) [E1]
|
|
|
2011 |
Melchers RE, 'Application of extreme value theory to discriminate between failure modes', Proceedings of the 11th International Conference on Applications of Statistics and Probability in Civil Engineering, Zurich, CH (2011) [E1] |
|
|
2011 |
Melchers RE, Ahammed M, Jeffrey RJ, Simundic G, 'Statistical analysis of the surfaces of corroded mild steel plates', Proceedings of the 11th International Conference on Applications of Statistics and Probability in Civil Engineering, Zurich, CH (2011) [E1]
|
|
|
2011 |
Melchers RE, 'Prediction of long-term corrosion for infrastructure applications', European Corrosion Congress 2011, Stockholm, Sweden (2011) [E2] |
|
|
2011 |
Melchers RE, 'The role of nutrients and water pollution in the bacterial corrosion of structural steels', Symposium on Microbiologically Influenced Corrosion Papers, Melbourne, Vic (2011) [E1] |
|
|
2011 |
Melchers RE, 'Observations about the corrosion of reinforcement in marine environments', XII DBMC: International Conference on Durability of Building Materials and Components, Porto, Portugal (2011) [E1] |
|
|
2010 |
Melchers RE, Jeffrey RJ, 'Experimental investigation of accelerated low water corrosion of steel piling in habours', Proceedings of the 2nd International Conference on the Structures Degradation in Coastal Zones, La Rochelle, France (2010) [E1]
|
|
|
2010 |
Melchers RE, Pape TM, 'Aspects of long-term durability of reinforced concrete structures in marine environments', Proceedings of the 2nd International Conference on the Structures Degradation in Coastal Zones, La Rochelle, France (2010) [E1]
|
|
|
2010 |
Melchers RE, 'The time to commencement of reinforcement corrosion in marine environments', Proceedings of the 6th International Conference on Concrete Under Severe Conditions, Yucatan, Mexico (2010) [E1]
|
|
|
2010 |
Melchers RE, Chernov BB, 'High temperature hard freshwater corrosion loss of mild steel', TEAM 2010 Vladivostok: The 24th Asian-Pacific Technical Exchange and Advisory Meeting on Marine Structures: Program and Proceedings, Vladivostok, Russia (2010) [E1]
|
|
|
2010 |
Melchers RE, Li CQ, 'Predicting the life of reinforced concrete structures in severe marine environments', BRIDGE MAINTENANCE, SAFETY, MANAGEMENT AND LIFE-CYCLE OPTIMIZATION, Lehigh Univ, Adv Technol Large Struct Syst (ATLSS) Engn Res Ctr, Philadelphia, PA (2010) [E2] |
|
|
2010 |
Melchers RE, 'Experiments, science and probability theory in building new models for long-term pitting corrosion in marine environments', Safety, Reliability and Risk of Structures, Infrastructures and Engineering Systems: Proceedings of the Tenth International Conference on Structural Safety and Reliability (ICOSSAR2009), Osaka, Japan (2010) [E1] |
|
|
2010 |
Melchers RE, 'Structural reliability theory in the wider safety context', Safety, Reliability and Risk of Structures, Infrastructures and Engineering Systems: Proceedings of the Tenth International Conference on Structural Safety and Reliability (ICOSSAR2009), Osaka, Japan (2010) [E1] |
|
|
2010 |
Schoefs F, Boero J, Capra B, Melchers RE, 'Statistical analysis of corrosion process along French coasts', Safety, Reliability and Risk of Structures, Infrastructures and Engineering Systems: Proceedings of the Tenth International Conference on Structural Safety and Reliability (ICOSSAR2009), Osaka, Japan (2010) [E1] |
|
|
2010 |
Melchers RE, Li CQ, 'Predicting the life of reinforced concrete structures in severe marine environments', Bridge Maintenance, Safety, Management and Life-Cycle Optimization - Proceedings of the 5th International Conference on Bridge Maintenance, Safety and Management, Philadelphia, United States (2010) [E1] |
|
|
2010 |
Melchers RE, 'Observations about the performance of reinforcement in marine environments', CECAR 5. ASEC 2010. 5th Civil Engineering Conference in the Asian Region and Australasian Structural Engineering Conference 2010, Sydney, NSW (2010) [E1] |
|
|
2010 |
Melchers RE, Wells PA, 'Modelling the long term corrosion of reinforced concrete sewers', Leading-Edge Conference on Water and Wastewater Treatment Technologies, Phoenix, AZ (2010) [E1] |
|
|
2010 |
Jeffrey RJ, Melchers RE, 'Variability of corrosion of mild steel coupons in tidal, splash and atmospheric marine environments', Corrosion and Prevention 2010: Always Protecting, Always Learning, Adelaide, SA (2010) [E1]
|
|
|
2010 |
Chaves IA, Melchers RE, Fontaine E, 'A field investigation of pitting corrosion of welded pipeline steels', Proceedings of the ACA Conference: Corrosion and Prevention 2010, Adelaide, SA (2010) [E1]
|
|
|
2010 |
Melchers RE, Jeffrey RJ, Simundic G, 'Representativeness of small coupons for corrosion of large plates', Proceedings of the ACA Conference: Corrosion and Prevention 2010, Adelaide, SA (2010) [E1]
|
|
|
2010 |
Melchers RE, Jeffrey RJ, 'On predicting long-term corrosion behaviour from short-term tests', Proceedings of the ACA Conference: Corrosion and Prevention 2010, Adelaide, SA (2010) [E1]
|
|
|
2010 |
Jeffrey RJ, Melchers RE, 'The effect of microbiological involvement on the topography of corroding mild steel in coastal seawater', NACE Corrosion Conference & Expo 2010, San Antonio, TX (2010) [E1]
|
|
|
2010 |
Melchers RE, Jeffrey RJ, 'Corrosion of vertical steel strips exposed in the marine tidal zone and implications for ALWC', NACE Corrosion Conference & Expo 2010, San Antonio, TX (2010) [E1]
|
|
|
2009 |
Melchers RE, 'Failure mechanism of the Newcastle Workers Club', AEES 2009 Program, Newcastle, NSW (2009) [E3] |
|
|
2009 |
Melchers RE, 'Ensuring validity and quality of deterioration models for structural reliability assessment', ICCES'09 Conference Program & Souvenir, Phuket, Thailand (2009) [E3] |
|
|
2009 |
Melchers RE, 'Reliability theory and estimating the likely safety of constructed facilities', Futures in Mechanics of Structures and Materials: Proceedings of the 20th Australasian Conference on the Mechanics of Structures and Materials, Toowoomba, QLD (2009) [E1] |
|
|
2009 |
Fontaine E, Armstrong R, Potts A, Melchers RE, Chaplin CR, Francois M, 'Semi-empirical modeling for seawater corrosion of wire rope', Proceedings of the Nineteenth (2009) International Offshore and Polar Engineering Conference (ISOPE), Osaka, Japan (2009) [E1]
|
|
|
2009 |
Papè T, Melchers R, 'Comparisons between two corrosion assessment methods and the corrosion of steel in prestressed concrete', 49th Annual Conference of the Australasian Corrosion Association 2009: Corrosion and Prevention 2009, Coffs Harbour, NSW, Australia (2009) [E1]
|
|
|
2009 |
Jeffrey RJ, Melchers RE, 'Corrosion of isolated and electrically-connected steel coupons in temperate coastal seawater', Corrosion & Prevention 2009: The Management of Infrastructure Deterioration: Conference Proceedings, Coffs Harbour, NSW (2009) [E1]
|
|
|
2009 |
Jeffrey RJ, Melchers RE, 'The effect of seawater sterilisation on the corrosion of mild steel', Corrosion & Prevention 2009: The Management of Infrastructure Deterioration: Conference Proceedings, Coffs Harbour, NSW (2009) [E1]
|
|
|
2009 |
Melchers RE, 'Experiments, science and intuition in the development of models for the corrosion of steel infrastructure', Corrosion & Prevention 2009: The Management of Infrastructure Deterioration: Conference Proceedings, Coffs Harbour, NSW (2009) [E1]
|
|
|
2009 |
Melchers RE, Li CQ, 'Time to initiation of reinforcement corrosion in marine environments: A review of older concrete structures', Corrosion & Prevention 2009: The Management of Infrastructure Deterioration: Conference Proceedings, Coffs Harbour, NSW (2009) [E1] |
|
|
2009 |
Pape TM, Melchers RE, 'Comparisons between two corrosion assessment methods and the corrosion of steel in prestressed concrete', Corrosion & Prevention 2009: The Management of Infrastructure Deterioration: Conference Proceedings, Coffs Harbour, NSW (2009) |
|
|
2009 |
Wells PA, Melchers RE, Bond P, 'Factors involved in the long term corrosion of concrete sewers', Corrosion & Prevention 2009: The Management of Infrastructure Deterioration: Conference Proceedings, Coffs Harbour, NSW (2009) [E1]
|
|
|
2008 |
Melchers RE, Jeffrey RJ, 'Evidence for microbiological influenced longer-term corrosion in tidal and coastal atmospheric corrosion of steel elements', Corrosion & Prevention 2008: The Impact of Corrosion on our Lives: Conference Proceedings, Wellington, NZ (2008) [E1]
|
|
|
2008 |
Melchers RE, Li CQ, 'Long-term observations of reinforcement corrosion for concrete elements exposed to the North Sea', Corrosion & Prevention 2008: The Impact of Corrosion on our Lives: Conference Proceedings, Wellington, NZ (2008) [E1]
|
|
|
2008 |
Jeffrey RJ, Melchers RE, 'Corrosion profiles of mild steel in varying tidal seawaters', Corrosion & Prevention 2008: The Impact of Corrosion on our Lives: Conference Proceedings, Wellington, NZ (2008) [E1]
|
|
|
2008 |
Jeffrey RJ, Melchers RE, 'Three year observations of corrosion losses for steels at a severe marine atmospheric site', Corrosion & Prevention 2008: The Impact of Corrosion on our Lives: Conference Proceedings, Wellington, NZ (2008) [E1]
|
|
|
2008 |
Melchers RE, 'Long-term corrosion of steels exposed to marine environments', MEDACHS 08: Construction Heritage in Coastal and Marine Environments: Damage, Diagnostic, Maintenance and Rehabilitation, Lisbon, Portugal (2008) [E1]
|
|
|
2008 |
Melchers RE, Jeffrey RJ, 'Early test results and interpretations for corrosion of vertical steel strips exposed in the marine tidal zone', The 14th International Congress on Marine Corrosion and Fouling: Abstracts, Kobe, Japan (2008) [E3]
|
|
|
2008 |
Melchers RE, 'The critical role of marine bacterial processes in the development of models for pitting corrosion of structural steels', Life-Cycle Civil Engineering, Lake Como, Italy (2008) [E1]
|
|
|
2008 |
Pape TM, Melchers RE, 'Investigating the effects of corrosion on 45-year-old prestressed concrete bridge beams', Life-Cycle Civil Engineering, Lake Como, Italy (2008) [E1]
|
|
|
2008 |
Jeffrey R, Melchers R, 'Three year observations of corrosion losses for steels at a severe marine atmospheric site', 48th Annual Conference of the Australasian Corrosion Association 2008: Corrosion and Prevention 2008 (2008)
A large scale atmospheric corrosion trial extending over five years is currently being conducted at Belmont Beach near Newcastle, Australia. The intent is to obtain information ab... [more]
A large scale atmospheric corrosion trial extending over five years is currently being conducted at Belmont Beach near Newcastle, Australia. The intent is to obtain information about the effects of orientation, height and bold exposure versus shielding effects as well as detailed chronological observations and variability data for nominally identical exposures. Such comprehensive data has not previously been obtained for the one site and under the one local climatic regime for all coupons. This provides a much better and more controlled environment in which to compare the various effects. Failure to achieve this in previous studies renders the study of such influences problematic. Also, variability of nominally identically exposed coupons has not previously been given attention. The paper deals with the three-year results and compares these with information available in the literature. After three years most of the boldly exposed coupons have completely corroded but most of the single sided coupons remain in varying degrees. A comparison is given between individual coupons exposed at different heights and single strips of steel exposed over the same vertical distance.
|
|
|
2008 |
Melchers RE, 'New research findings for the atmospheric corrosion of steel structures and the development of predictive models for corrosion loss and pitting', Australasian Structural Engineering Conference 2008: Conference Proceedings, Melbourne, VIC (2008) [E1] |
|
|
2007 |
Jeffrey RJ, Melchers RE, 'Correlation between water temperature and corrosion of mild steel in different waters', Corrosion Control 007. Conference Proceedings, Sydney (2007) [E1]
|
|
|
2007 |
Gudze MT, Melchers RE, 'Prediction of corrosion in ballast tanks of naval ships using operational characteristics', Corrosion Control 007. Conference Proceedings, Sydney (2007) [E1] |
|
|
2007 |
Melchers RE, 'Modelling the corrosion losses for mild steel exposed to natural fresh, brackish and seawaters', Corrosion Control 007. Conference Proceedings, Sydney (2007) [E1] |
|
|
2007 |
Pape TM, Melchers RE, 'The effect of corrosion on 45 year-old prestressed concrete bridge beams', Corrosion Control 007. Conference Proceedings, Sydney (2007) [E1]
|
|
|
2007 |
Jeffrey RJ, Melchers RE, 'New data for verification of a phenomenological model for corrosion of steels in seawater', 1st Corrosion and Material Protection Conference 2007. Proceedings, Prague, Czech Republic (2007) [E2]
|
|
|
2007 |
Melchers RE, Jeffrey RJ, 'The critical involvement of anaerobic bacterial activity in modelling the corrosion behaviours of mild steel in marine environments', BIOCORYS 2007, Paris (2007) [E2]
|
|
|
2007 |
Melchers RE, Jeffrey RJ, 'The involvement of anaerobic bacteria in the corrosion of mild steel in water', MIC Symposium: An International Perspective. Proceedings, Perth (2007) [E2]
|
|
|
2007 |
Melchers RE, 'Development of high-quality engineering models for marine coastal zone corrosion of structural steels', SCAMI-2. 2nd International Conference on Structural Condition Assessment Monitoring and Improvement. Conference Proceedings, Changsha, China (2007) [E1] |
|
|
2007 |
Jeffrey RJ, Melchers RE, 'Corrosion profiles of mild steel in varying tidal seawaters', Second World Congress on Corrosion in the Military. Proceedings, Naples, Italy (2007) [E2]
|
|
|
2007 |
Melchers RE, 'Development of new applied models for steel corrosion in marine applications including shipping', 2007 PRADES. 10th International Symposium on Practical Design of Ships and Other Floating Structures, Houston, Texas (2007) [E1] |
|
|
2007 |
Melchers RE, 'Recent progress in the development of mathematical-probabilistic corrosion models for long-term life assessment of steel infrastructure', Applications of Statistics and Probability in Civil Engineering, Tokyo (2007) [E1]
|
|
|
2007 |
Melchers RE, 'Modelling the corrosion of steel infrastructure in marine environments for long-term reliability assessment', Lifetime-Oriented Design Concepts, 2007. Proceedings of the Third International Conference Lifetime-Oriented Design Concepts, Bochum, Germany (2007) [E2] |
|
|
2006 |
Melchers RE, 'The probabilistic prediction of short- and long-term maximum pit depth for steels immersed in seawater', Corrosion Modeling For Life Prediction 2006, Cernobbio, Lake Como, Italy (2006) [E2] |
|
|
2006 |
Melchers RE, 'Probabilistic modelling of long-term pitting corrosion of structural steel under marine immersion conditions', Corrosion and Prevention 2006, Hobart, Tasmania (2006) [E1]
|
|
|
2006 |
Melchers RE, 'From marine immersion to coastal atmospheric corrosion of mild steel: implications arising from long-term observations', Corrosion and Prevention 2006, Hobart, Tasmania (2006) [E1] |
|
|
2006 |
Jeffrey RJ, Melchers RE, 'Early observations of corrosion losses for steels at a severe marine atmospheric site', Corrosion and Prevention 2006, Hobart, Tasmania (2006) [E1]
|
|
|
2006 |
Jeffrey RJ, Melchers RE, 'Observations of corrosion losses for steels exposed in tidal seawaters', Corrosion and Prevention 2006, Hobart, Tasmania (2006) [E1]
|
|
|
2006 |
Melchers RE, 'Aspects of probabilistic risk assessment and remaining life prediction for pipelines under long-term pitting corrosion', International Conference and Exhibition on Pressure Vessels and Piping (OPE 2006), Chennai, India (2006) [E1] |
|
|
2006 |
Paik JK, Thayamballi AK, Melchers RE, 'Recent advances in corrosion assessment and management for ships and offshore structures', 5th International Conference on High Performance Marine Vehicles, Tasmania, Australia (2006) [E1] |
|
|
2006 |
Melchers RE, 'Advances in mathematical-probabilistic modelling of the atmospheric corrosion of structural steels in ocean environments', 3rd International ASRANet Colloquium, Glasgow, United Kingdom (2006) [E1] |
|
|
2006 |
Melchers RE, 'Assessment and prediction of remaining safe and serviceable life for corroding infrastructure', 19th Australasian Conference on the Mechanics of Structures and Materials, Christchurch, New Zealand (2006) [E1] |
|
|
2006 |
Pape TM, Melchers RE, 'The effect of corrosion on the capacity and behaviour of a 45 year-old post-tensioned concrete bridge beams', 19th Australasian Conference on the Mechanics of Structures and Materials, Christchurch, New Zealand (2006) [E1]
|
|
|
2005 |
Melchers RE, 'Observations About The Probabilistic Representation Of Uncertainty For Maximum Corrosion Pit Depths', Advances In Reliability And Optimization Of Structural Systems, Aalborg, Denmark (2005) [E2] |
|
|
2005 |
Melchers RE, 'The Corrosion Of Structural Steel In Seawater', Australian Structural Engineering Conference 2005, Newcastle, Australia (2005) [E1] |
|
|
2005 |
Wells PA, Melchers RE, 'Predictive Methods For Estimating The Durability Of Simple Composite Materials', Australian Stuctural Engineering Conference : ASEC 2005 : 11-14 September 2005, Newcastle City Hall, Newcastle, NSW, Australia. Program & abstract book, Newcastle, Australia (2005) [E1] |
|
|
2005 |
Li CQ, Lawanwisut W, Melchers RE, 'Reliability Analysis Of Corrosion Induced Concrete Cracking', 9th International Conference On Structural Safety And Reliability (ICOSSAR 2005), Rome, Italy (2005) [E1] |
|
|
2005 |
Melchers RE, 'Representation Of Uncertainty For Maximum Corrosion Pit Depth', 9th International Conference On Structural Safety And Reliability (ICOSSAR 2005), Rome, Italy (2005) [E1] |
|
|
2005 |
Melchers RE, 'Degradation Of The Reliability Of Steel Structures Due To Marine Immersion Corrosion', 9th International Conference On Structural Safety And Reliability (ICOSSAR 2005), Rome, Italy (2005) [E1] |
|
|
2005 |
Li CQ, Aguiar S, Melchers RE, 'Maintenance Strategy For Coastal Concrete Structures', 9th International Conference On Structural Safety And Reliability (ICOSSAR 2005), Rome, Italy (2005) [E1] |
|
|
2005 |
Ahammed M, Melchers RE, 'New Bounds For Highly Correlated Structural Series System', 9th International Conference On Structural Safety And Reliability (ICOSSAR 2005), Rome, Italy (2005) [E1]
|
|
|
2005 |
Melchers RE, 'Mathematical And Probabilistic Modelling Of Material Deterioriation With Application To Pitting Corrosion In Structural Steel Applications', Proceedings of the 4th International Workshop On Life-Cycle Cost Analysis and Design of Civil Infrastructure Systems, Cocoa Beach, USA (2005) [E1] |
|
|
2005 |
Melchers RE, 'Mathematical And Probabilistic Modelling For Seawater Corrosion Of Steels In Structural Applications', Proceedings of the 1st International Conference on Structural Condition Assessment, Monitoring and Improvement, Perth, Australia (2005) [E1] |
|
|
2005 |
Jeffrey RJ, Melchers RE, 'Corrosion Field Trials - Case Studies On Unsuccessful Atmospheric And Marine Immersion Studies', Corrosion and Prevention 2005, Gold Coast, QLD (2005) [E1]
|
|
|
2005 |
Jeffrey RJ, Melchers RE, 'The Changing Surface Topography Of Corroding Mild Steel In Sub-Tropical Coastal Waters', 16th International Corrosion Congress, Beijing, China (2005) [E2]
|
|
|
2005 |
Jeffrey RJ, Melchers RE, 'Morphology Of The Corrosion Products Of Mild Steel Immersed In Temperate Seawaters', 16th International Corrosion Congress, Beijing, China (2005) [E2]
|
|
|
2005 |
Melchers RE, Jiang XL, Lu KJ, 'Coating Life Prediction For Water Ballast Tank', 24th International Conference on Offshore Mechanics and Arctic Engineering (OMAE 2005), Halkidiki, Greece (2005) [E2] |
|
|
2005 |
Melchers RE, 'The Probability Of Occurrence For Pits Of Maximum Depth - Upsetting 50 Years Of Convention', Corrosion and Prevention 2005, Gold Coast, Australia (2005) [E1]
|
|
|
2004 |
Gudze M, Cannon S, Melchers RE, 'Ballast Tank Corrosion Using Naval Ship Operational Profiles', Proceedings of the Pacific 2004 International Maritime Conference, Sydney, Australia (2004) [E1] |
|
|
2004 |
Wells PA, Melchers RE, 'Determining Hydrolysis Behavior And Durability From Short Term Water Absorption Data', Proceedings of the Second International Conference on FRP Composites In Civil Engineering, Adelaide, Australia (2004) [E1] |
|
|
2004 |
Melchers RE, Ahammed M, 'Characterization Of Corroded Steel Plate Surfaces', Proceedings of the 18th Australasian Conference on the Mechanics of Structures and Materials, Perth, Australia (2004) [E1]
|
|
|
2004 |
Jeffrey RJ, Melchers RE, 'Migration Of Iron Particles, Ions and Compounds During Long-Term Marine Immersion Corrosion', Corrosion and Prevention 2004, Perth, Australia (2004) [E1]
|
|
|
2004 |
Jeffrey RJ, Melchers RE, 'Influence Of Tidal Movement On Marine Immersion Corrosion Of Mild Steel - Preliminary Results', Corrosion and Prevention 2004, Perth, Australia (2004) [E1]
|
|
|
2004 |
Melchers RE, 'Variability Of Maximum Pit Depth For Mild Steel In Seawater', Corrosion and Prevention 2004, Perth, Australia (2004) [E1] |
|
|
2004 |
Melchers RE, 'The Effect Of Corrosion On The Structural Reliability Of Steel Offshore Structures', International Symposium on Corrosion and Protection of Marine Structures, Muroran Institute of Technology, Japan (2004) [E2] |
|
|
2004 |
Melchers RE, 'Mathematical Modelling Of Marine Immersion Corrosion For Structural Reliability Assessment', Proceedings of the Third Asian Pacific Symposium on Structural Reliability and its Applications, Seoul, Korea (2004) [E1] |
|
|
2003 |
Jeffrey RJ, Melchers RE, 'An XRD Study Of The Products Of Corrosion Of Mild Steel Immersed In Coastal Conditions', Corrosion Control And NDT, Melbourne, Australia (2003) [E1]
|
|
|
2003 |
Melchers RE, 'Pitting Corrosion Of Mild Steel In Marine Immersion Environments', Corrosion Control And NDT, Melbourne, Australia (2003) [E1] |
|
|
2003 |
Melchers RE, Jeffrey RJ, 'Observations On The Effect Of Surface 'Roughness' In The Marine Immersion Corrosion Of Mild Steel Coupons', Corrosion Control And NDT, Melbourne, Australia (2003) [E1]
|
|
|
2003 |
Melchers RE, 'Modelling Of Long-Term Performance Of Structural Steel Under Marine Corrosion Conditions', Proceedings Of The International Conference On Performance Of Construction Materials In The New Millenium (ICPCM), Cairo, Egypt (2003) [E1] |
|
|
2003 |
Beck AT, Melchers RE, 'Fatigue And Fracture Reliability Analysis Under Random Loading', Proceedings Of The Second MIT Conference On Computational Fluid And Solid Mechanics, Cambridge, Massachusetts, United States (2003) [E2] |
|
|
2003 |
Moarefzadeh MR, Melchers RE, 'Nonlinear Wave Effect In Reliability Analysis Of Offshore Structures', Extreme Loading Conference: Response Of Structures To Extreme Loading, Toronto, Canada (2003) [E2] |
|
|
2003 |
Melchers RE, Ahammed M, 'Numerical Estimation Of Sensitivities For Complex Probabilistically-Described Systems', Proceedings Of The Ninth International Conference On Civil And Structural Engineering Computing, Egmond-aan-Zee, The Netherlands (2003) [E2]
|
|
|
2003 |
Gray WA, Melchers RE, 'A Comparison Of Some Numerical Methods Available For The Estimation Of Time-Invariant Reliability', Proceedings Of The Sixth Engineering Mathematics And Applications Conference, Sydney, Australia (2003) [E1] |
|
|
2003 |
Gray WA, Melchers RE, 'A Comparison Of Some Numerical Methods For Estimating Time-Invariant Reliability', Proceedings Of The 9th International Conference On Applications Of Statistics And Probability In Civil Engineering, San Francisco, California, United States (2003) [E1] |
|
|
2003 |
Melchers RE, 'A New Model For Marine Immersion Corrosion In Structural Reliability Assessment', Proceedings Of The 9th International Conference On Applications Of Statistics And Probability In Civil Engineering, San Francisco, California, United States (2003) [E1] |
|
|
2003 |
Beck AT, Melchers RE, 'On The Ensemble Up-Crossing Rate Approach To Time Variant Reliability Analysis Of Uncertain Structures', Proceedings Of The Fourth International Conference On Computation Stochastic Mechanics, Corfu, Greece (2003) [E2] |
|
|
2002 |
Jeffrey RJ, Melchers RE, 'Effect Of Seawater Velocity On Immersion Corrosion Of Mild Steel', Corrosion And Prevention - 02, Adelaide, South Australia (2002) [E1]
|
|
|
2002 |
Melchers RE, Jeffrey RJ, 'Variability In Corrosion Of Mild Steel Coupons In Seawater', Corrosion And Prevention 02, Adelaide, South Australia (2002) [E1]
|
|
|
2002 |
Jeffrey RJ, Melchers RE, 'Influence Of Edge Effect On Marine Immersion Corrosion Measurement For Mild Steel Coupons', 15th International Corrosion Congress, Granada, Spain (2002) [E2]
|
|
|
2002 |
Jeffrey RJ, Melchers RE, 'Images Of Bacteriological Influence In The Development Of Iron Sulphide In Marine Immersion Environments', 15th International Corrosion Congress, Granada, Spain (2002) [E2]
|
|
|
2002 |
Melchers RE, 'Stochastic Computational Mechanics - With Emphasis On Mechanics Modelling', ASRANet, Glasgow, Scotland (2002) [E1] |
|
|
2002 |
Melchers RE, Stewart MG, 'Risk-Based Predictions Of Service Life Performance', IABSE Symposium, Melbourne, Australia (2002) [E1]
|
|
|
2002 |
Beck AT, Melchers RE, 'A Comparison Of Some Methods For Fatigue And Fracture Reliability Estimation Under Random Loading', Proceedings Of The 17th Australasian Conference On The Mechanics Of Structures And Materials, Gold Coast, Queensland, Australia (2002) [E1] |
|
|
2002 |
Khennane A, Melchers RE, 'A Finite Element Approach For Modeling The Statistical Strength Of A Unidirectional Composite', Proceedings Of The 17th Australasian Conference On The Mechanics Of Structures And Materials, Gold Coast, Queensland, Australia (2002) [E1] |
|
|
2002 |
Masia MJ, Kleeman PW, Melchers RE, 'Soil/Structure Interation Modelling Of Masonry For Reliability Studies', Proceedings of the 17th Australasian Conference on the Mechanics of Structures and Materials, Gold Coast, Queensland, Australia (2002) [E1]
|
|
|
2001 |
Melchers RE, 'Probabilistic models of corrosion for reliability assessment and maintenance planning - CD-ROM', Proceedings of OMAE'01 20th International Conference on Offshore Mechanics and Arctic Engineering, Brazil (2001) [E1]
|
|
|
2001 |
Gardiner CP, Melchers RE, 'Bulk Carrier Corrosion Modelling', Proceedings of the Eleventh (2001) International Offshore and Polar Engineering Conference, Norway (2001) [E1]
|
|
|
2001 |
Jeffrey RJ, Melchers RE, 'Bacteriological influence in the development of iron sulphide species in marine immersion environments', Proceedings of Corrosion and Prevention - 2001, Newcastle (2001) [E1]
|
|
|
2001 |
Khennane A, Melchers RE, 'Stress corrosion of glass fibre reinforced polymers for infrastructure applications', Proceedings of Corrosion and Prevention - 2001, Newcastle (2001) [E1] |
|
|
2001 |
Melchers RE, 'A phenomenological model for 'at-sea' marine immersion corrosion of mild steel', Proceedings of Corrosion and Prrevention - 2001, Newcastle (2001) [E1] |
|
|
2001 |
Faber MH, Melchers RE, 'Aspects of safety in design and assessment of deteriorating structures', Conference Report on Safety, Risk and Relaibility - Trends in Engineering, Malta (2001) [E2] |
|
|
2001 |
Masia MJ, Melchers RE, 'Serviceability and Reliability of Structures Subject to Ground Movement', Proceedings of the 4th Triennial Conference on Coal Mine Subsidence 2001, Maitland (2001) [E2]
|
|
|
2001 |
Khennane A, Melchers RE, 'A micromechanics model for environmental stress corrosion in GFRP', Proceedings of the International Conference on FRP Composites in Civil Engineering, Hong Kong, China (2001) [E1] |
|
|
2000 |
Melchers RE, 'Influence of Temperature on Marine Corrosion of 90:10 Copper-Nickel Alloy', Corrosion & Prevention - 2000, Auckland, New Zealanad (2000) [E1] |
|
|
2000 |
Jeffrey RJ, Melchers RE, 'Boundary Conditions of Marine Immersion Coupons', Corrosion & Prevention - 2000, Auckland, New Zealand (2000) [E1]
|
|
|
2000 |
Kordzakhia N, Melchers RE, Novikov A, 'First Passage of Filtered Poisson Processes with Exponential', PMC2000 Proceedings of the 8th ASCE Joint Specialty Conference, University of Notre Dame, USA (2000) [E2] |
|
|
2000 |
Guan X-L, Melchers RE, 'A parametric Study on the Response Surface Method', PMC2000 Proceedings of the 8th ASCE Joint Specialty Conference, University of Notre Dame, USA (2000) [E2] |
|
|
2000 |
Masia MJ, Melchers RE, Kleeman PW, 'A probabilistic model for the prediction of cracking in masonry structures', Proceedings of the 12th International Brick/Block Masonry Conference, Madrid, Spain (2000) [E2]
|
|
|
2000 |
Melchers RE, Stewart MG, 'Proceedings of the ICASP8 Conference, Applications of Statistics and Probability', Proceedings of the ICASP8 Conference, Applicatiosn of Statistics and Probability, Sydney (2000) [E4]
|
|
|
2000 |
Guan X-L, Melchers RE, 'A Comparison of some FOSM and Monte Carlo results', Proceedings of the ICASP8 Conference: Applications of Statistics and Probability, Sydney, Australia (2000) [E1]
|
|
|
2000 |
Kordzakhia N, Melchers RE, 'First passage analysis of a 'square wave' filtered Poisson process', Proceedings of the ICASP8 Conference: Applications of Statistics and Probability, Sydney, Australia (2000) [E1] |
|
|
2000 |
Melchers RE, 'Optimization of Structural Reliability and Structural Safety', Proceedings of the Ninths IFIP WG 7.5 Working Conference on Reliability and optimization of structural system, 2000, The University of Michigan, USA (2000) [E1] |
|
|
1999 |
Melchers RE, 'Early and longer term prediction of immersion corrosion of steel in marine waters', Proceedings Corrosion & Prevention-99, Sydney, Australia (1999) [E1] |
|
|
1999 |
Jeffrey RJ, Melchers RE, 'Influence of environmental factors on the early corrosion of steel in coastal seawater', Proceedings Corrosion & Prevention-99, Sydney, Australia (1999) [E1]
|
|
|
1999 |
Gardiner CP, Melchers RE, 'Enclosed atmospheric corrosion in an unloaded bulk carrier cargo hold', Proceedings Corrosion & Prevention-99, Sydney, Australia (1999) [E1] |
|
|
1999 |
Melchers RE, Guan X-L, 'Finite element analysis in structural reliability', Proceedings of the 16th Australasian conference on the Mechanics of Structures and Materials, Sydney, Australia (1999) [E1] |
|
|
1999 |
Melchers RE, 'Developments in directional stimulation for structural reliability estimation', Proceedings of the Asian-Pacific Symposium on Structural Reliability and its Applications, Taipei, Taiwan (1999) [E2] |
|
|
1999 |
Melchers RE, 'Factors influencing the immersion corrosion of steels in marine waters', Proceedings on 14th International Corrosion Congress, Cape Town, South Africa (1999) [E1] |
|
|
1998 |
Ellingwood B, Nowak A, Melchers RE, Thoft-Christensen P, Furuta H, Vrouwenvelder T, 'Summary of Panel Discussion: New generation of codes', STRUCTURAL SAFETY AND RELIABILITY, VOLS. 1-3, INT ASSOC STRUCT SAFETY & RELIABIL, KYOTO, JAPAN (1998) |
|
|
1998 |
Val D, Melchers RE, 'Reliability analysis of deteriorating reinforced concrete frame structures', STRUCTURAL SAFETY AND RELIABILITY, VOLS. 1-3, INT ASSOC STRUCT SAFETY & RELIABIL, KYOTO, JAPAN (1998)
|
|
|
1998 |
Guan XL, Melchers RE, 'Piece-wise linear models for reliability estimation with finite elements', STRUCTURAL SAFETY AND RELIABILITY, VOLS. 1-3, INT ASSOC STRUCT SAFETY & RELIABIL, KYOTO, JAPAN (1998) |
|
|
1998 |
Melchers RE, 'Probabilistic modelling of immersion marine corrosion', STRUCTURAL SAFETY AND RELIABILITY, VOLS. 1-3, INT ASSOC STRUCT SAFETY & RELIABIL, KYOTO, JAPAN (1998)
|
|
|
1998 |
Melchers RE, 'Aspects of Seismic Risk for Existing Infrastructure in Intraplate Regions', Asian-Pacific Workshop on Seismic Design and Retrofit of Structures, Taipei (1998) [E2] |
|
|
1998 |
Val DV, Stewart MG, Melchers RE, 'A Probabilistic Approach to the Evaluation of Reinforced Concrete Bridges', Developments in Short and Medium Span Bridge Engineering '98, Calgary (1998) [E1]
|
|
|
1998 |
Gardiner CP, Melchers RE, 'Aspects of Bulk Carrier Hold Corrosion', International Conference on Design and Operation of Bulk Carriers, London (1998) [E2] |
|
|
1998 |
Hough R, Melchers RE, 'Lightweight Structures in Architecture Engineering and Construction Vol. 1', Lightweight Structures in Architecture Engineering and Construction, Vol 1, Australia (1998) [E4] |
|
|
1998 |
Hough R, Melchers RE, 'Lightweight Structures in Architecture Engineering and Construction Vol 2', Lightweight Structures in Architecture Engineering and Construction, Vol 2, Australia (1998) [E4] |
|
|
1998 |
Melchers RE, 'Immersion Corrosion of Steels in Marine and Brackish Waters', Proceedings Australasian Corrosion Association Inc, Hobart (1998) [E1] |
|
|
1998 |
Melchers RE, 'Infrastructure Performance and Research Needs', Proceedings of the Australasian Structural Engineering Conference, Auckland (1998) [E1] |
|
|
1998 |
Val DV, Stewart MG, Melchers RE, 'Assessment of Existing RC Structures: Statistical and Reliability Issues', Proceedings of the Second International RILEM/CSIRO/ACRA Conference, Melbourne, Australia (1998) [E2]
|
|
|
1998 |
Melchers RE, 'Load Path Dependence for Directional Simulation in the Load Space', Proceedings of the eighth IFIP WG7.5 working conference on reliability and optimization of structural systems, 1998, Krakow, Poland (1998) [E1] |
|
|
1998 |
Stewart MG, Melchers RE, 'Integrated Risk Assessment', Proceedings of the third conference on Integrated Risk Assessment, Newcastle, Australia (1998) [E4]
|
|
|
1998 |
Stewart MG, Val DV, Melchers RE, 'Risk-based assessment of deteriorating infrastructure', Proceedings of the third conference on integrated risk assessment, Newcastle, Australia (1998) [E2]
|
|
|
1998 |
Melchers RE, 'Marine Corrosion of Mild and Low Alloy Steels', SEWC '98, California, USA (1998) [E1] |
|
|
1998 |
Val D, Stewart MG, Melchers RE, 'Reliability of Reinforced Concrete Bridges With Corroded Reinforcement', SEWC Conference Proceedings, San Francisco, USA (1998) [E2]
|
|
|
1997 |
Melchers RE, 'Corrosion of steel in seawater - A poorly formulated but important practical problem', MECHANICS OF STRUCTURES AND MATERIALS, UNIV MELBOURNE, MELBOURNE, AUSTRALIA (1997) |
|
|
1996 |
Melchers RE, 'Towards a probabilistic model for marine corrosion of steel', PROBABILISTIC MECHANICS & STRUCTURAL RELIABILITY, WORCESTER, MA (1996) |
|
|
1996 |
Guan XL, Melchers RE, 'Load space formulation for reliability estimation of complex structures', PROBABILISTIC MECHANICS & STRUCTURAL RELIABILITY, WORCESTER, MA (1996) |
|
|
1996 |
Melchers RE, Jeulin D, 'Synthesis of session 2c: Mechanics of materials: Durability, serviceability', APPLICATIONS OF STATISTICS AND PROBABILITY: CIVIL ENGINEERING RELIABILITY AND RISK ANALYSIS, VOL 3 - FINAL REPORT, PARIS, FRANCE (1996) |
|
|
1995 |
MELCHERS RE, 'PROBABILISTIC MODELING OF MARINE CORROSION OF STEEL SPECIMENS', PROCEEDINGS OF THE FIFTH (1995) INTERNATIONAL OFFSHORE AND POLAR ENGINEERING CONFERENCE, VOL IV, THE HAGUE, NETHERLANDS (1995)
|
|
|
1995 |
MELCHERS RE, 'Probabilistic calibration against existing practice as a tool for risk acceptability assessment', INTEGRATED RISK ASSESSMENT, NEWCASTLE, AUSTRALIA (1995)
|
|
|
1995 |
MELCHERS RE, 'Probabilistic modelling of seawater corrosion of steel structures', APPLICATIONS OF STATISTICS AND PROBABILITY: CIVIL ENGINEERING RELIABILITY AND RISK ANALYSIS, VOLS 1 AND 2, PARIS, FRANCE (1995)
|
|
|
1994 |
MELCHERS RE, 'POISSON PROCESSES IN LOAD SPACE RELIABILITY', STRUCTURAL SAFETY & RELIABILITY, VOLS 1-3, INNSBRUCK, AUSTRIA (1994) |
|
|
1994 |
LI CQ, MELCHERS RE, 'METHODS TO ASSESS TIME-DEPENDENT SERVICEABILITY OF CONCRETE STRUCTURES', STRUCTURAL SAFETY & RELIABILITY, VOLS 1-3, INNSBRUCK, AUSTRIA (1994) |
|
|
1993 |
MELCHERS RE, 'EARTHQUAKE HAZARD IN AUSTRALIA AND RATIONAL MANAGEMENT STRATEGIES', ENVIRONMENTAL MANAGEMENT : GEO-WATER AND ENGINEERING ASPECTS, WOLLONGONG, AUSTRALIA (1993) |
|
|
1993 |
GUAN XL, MELCHERS RE, 'A NEW PROBABILISTIC FINITE-ELEMENT FORMULATION FOR RELIABILITY-ANALYSIS', PROBABILISTIC METHODS IN GEOTECHNICAL ENGINEERING, CANBERRA, AUSTRALIA (1993)
|
|
|
1993 |
MELCHERS RE, 'MODERN COMPUTATIONAL TECHNIQUES FOR RELIABILITY ESTIMATION', PROBABILISTIC METHODS IN GEOTECHNICAL ENGINEERING, CANBERRA, AUSTRALIA (1993) |
|
|
1993 |
TAN CP, DONALD IB, MELCHERS RE, 'PROBABILISTIC SLIP CIRCLE ANALYSIS OF EARTH AND ROCKFILL DAMS', PROBABILISTIC METHODS IN GEOTECHNICAL ENGINEERING, CANBERRA, AUSTRALIA (1993)
|
|
|
1993 |
MELCHERS RE, 'ON THE TREATMENT OF UNCERTAINTY INFORMATION IN PRA', PROBABILISTIC RISK AND HAZARD ASSESSMENT, NEWCASTLE, AUSTRALIA (1993) |
|
|
1993 |
AHAMMED M, MELCHERS RE, 'PROBABILISTIC ASSESSMENT OF PIPELINE SERVICE LIFE BASED ON PITTING CORROSION LEAKS', PROBABILISTIC RISK AND HAZARD ASSESSMENT, NEWCASTLE, AUSTRALIA (1993)
|
|
|
1993 |
LI CQ, MELCHERS RE, 'A PRACTICAL METHOD TO ASSESS TIME-DEPENDENT STRUCTURAL SYSTEM RELIABILITY', PROBABILISTIC RISK AND HAZARD ASSESSMENT, NEWCASTLE, AUSTRALIA (1993)
|
|
|
1993 |
MELCHERS RE, 'SOCIETY, TOLERABLE RISK AND THE ALARP PRINCIPLE', PROBABILISTIC RISK AND HAZARD ASSESSMENT, NEWCASTLE, AUSTRALIA (1993)
|
|
|
1992 |
Melchers RE, 'Developments in structural reliability assessment under complex load conditions', Proceedings of the International Offshore Mechanics and Arctic Engineering Symposium (1992)
An important part of the assessment of the reliability of offshore structures involves the estimation of the reliability of the structural system. Most offshore systems are subjec... [more]
An important part of the assessment of the reliability of offshore structures involves the estimation of the reliability of the structural system. Most offshore systems are subject to a number of load processes (e.g., wave load, wind load, earthquake load, etc.). It is clear that not all these processes will be at their peak value at the same time. Hence a representation is necessary which considers the temporal effect of the loading processes. Much conventional structural reliability theory has relied on the use of a 'load combination' approach to represent loads. However, such an approach is not valid unless structures behave linearly elastically to failure. The paper outlines some new directions in the assessment of structural reliability for structures subject to a number of loading processes and which may be deteriorating or changing their resisting values with time. In particular, attention is given to modern methods of simulation to solve the surface integral required for 'time-dependent' reliability evaluation. As is indicated, the computations involves are not necessarily significantly more complex than those which are currently required for so-called 'time-independent' reliability assessments.
|
|
|
1990 |
MELCHERS RE, 'PROBABILISTIC PROPERTIES OF THIN-WALLED ELEMENTS', THIN-WALLED STRUCTURES, MONASH UNIV, MELBOURNE, AUSTRALIA (1990)
|
|
|
1988 |
MELCHERS RE, 'STRUCTURAL OPTIMIZATION IN A NON-DETERMINISTIC SETTING', STRUCTURAL OPTIMIZATION /, MELBOURNE, AUSTRALIA (1988) |
|
|
1973 |
Melchers RE, 'OPTIMAL DESIGN OF VARIABLE THICKNESS REINFORCED PLATES.' (1973)
A general optimality condition is indicated for laterally loaded plates reinforced with fibers in their outer faces only. This result is applied to two examples. The first is a si... [more]
A general optimality condition is indicated for laterally loaded plates reinforced with fibers in their outer faces only. This result is applied to two examples. The first is a simply supported circular plate for which the thickness variation is specified. It is found that an optimal design has only radial fibres. The second problem is a simply supported square plate under arbitrary loading, for which the reinforcement fibers have different internal lever-arms in bending for different orientations within the plan of the plate.
|
|
|