ISSN 2282-1767
Protective Coatings ®
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THE MAGAZINE ABOUT CORROSION CONTROL AND PREVENTION TECHNOLOGIES 2019 - 8th Year | Quarterly - N.32 December
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in parallel with: Japanese Technology since 1912
in this issue © Shutterstock
01 EDITOR’S LETTER
02
02 ANALYSIS Surprising discovery could change the way industry uses nickel
04
External coating + cathodic protection: the safe way to protect buried and submerged pipelines
12
© Mengying Liu
© IGS
08 BRAND NEW
28
12 HIGHLIGHT OF THE MONTH Women in corrosion
© ipcm
16 INNOVATIONS Corrosion consequences on the high seas
20 FOCUS ON TECHNOLOGY Cold bonding: an attractive and convenient solution for corroding marine vessel deck plates
28
A new shot blasting plant for higher paint adhesion on Isoplus Mediterranean’s oil & gas pipelines
© Adobe Stock
20
30
48
32 SUCCESS STORIES The evolution of high velocity thermal spray: from shop applications to mission critical equipment protection
© motaen.com
48 INNOVATIONS 35 SPECIAL ON PROTECTIVE TECHNOLOGIES FOR BRIDGES, HIGHWAYS, INFRASTRUCTURES
LUMIFLONTM resins for bridge coatings
54 HIGHLIGHT OF THE MONTH Dynamic infrastructure implements deep AI technology to prevent bridges and tunnels from collapsing
36 ANALYSIS
42
Polymer modiȴed cementitious coatings on concrete to control chloride-induced corrosion of steel rebars
56 INNOVATIONS
Zinc spray galvanising: the preferred choice against the corrosion of steel bridge structures
62
44 BRAND NEW 47 HIGHLIGHT OF THE MONTH RICS: the growth opportunities and critical issues of the Italian infrastructure market
Perfect team for eco-friendly corrosion protection systems Cracking the code of biomass corrosion with HVTS
64 INSPECTION LOGBOOK Coating inspections: capability levels of coating inspection personnel
66 ZOOM ON EVENTS
EDITOR’S LETTER
I
t is once again an Italian tragedy, thankfully an escaped one this time, the starting point of the editorial of this ipcm®_Protective Coatings issue, which focusses on technologies aimed
at protecting and safeguarding bridges and infrastructure against corrosion and failure. A
viaduct of the Turin-Genoa highway collapsed due to the torrential rain that poured down non-stop in November. A driver’s readiness and cool-headedness luckily averted the tragedy: the incident ended with no victims, but with another structure closed for an indeȴnite period
of time. In this case, the structural failure was not, or at least not only, due to corrosion, but rather to a landslide. However, the episode further placed the state of preservation of Italian bridges under a magnifying glass, as most of them were built between 1955 and 1980. The result of this analysis raised the number of risky bridges needing an inspection from 10,000 to 60,000. Many actions should be implemented and several parties call for the implementation of a “Marshall Plan” for the Italian infrastructure. The rest of Europe does not sail in calmer waters, since some countries have more bridges and viaducts in a critical state than Italy, not to mention the United States, where NACE studies have repeatedly highlighted a dangerous situation. Maintenance is essential, but it is well known that prevention is far more eective, especially because the environmental and use conditions of infrastructure are becoming more and more severe. This last 2019 issue of ipcm®_Protective Coatings presents an extensive overview of technologies to counter the corrosion of bridges, viaducts, and road infrastructure in general, such as thermal spray coatings, once limited to factory applications but now widely tired and tested even for on-site operations; FEVE resins for paint formulations with exceptional outdoor resistance; and low-environmental impact painting systems, such as the waterbased ones that integrate pigments, resins, and binders tailored to guarantee corrosion resistance, but with less environmental impact than conventional solvent-based systems. It also includes an in-depth report of the Department of Chemistry, Materials, and Chemical Engineering “G.bNatta” of Politecnico di Milano about “Polymer modiȴed cementitious coatings on concrete to control chloride-induced corrosion of steel rebars”. Politecnico di Milano, and especially its PoliLaPP “Pietro Pedeferri” laboratory, is a centre of excellence in the world for research on corrosion control technologies. We hope that the prevention and maintenance of bridges and infrastructure will never again be solicited by catastrophic collapses, but that a wide-ranging intervention plan will be implemented so that we can continue to safely drive, walk, and travel on and under the bridges of our countries.
Alessia Venturi Editor-in-chief
ipcm® Protective Coatings - 2019 DECEMBER - N.32
01
SEM im mage off co corro corro r ded d nicke nicke kell at ke a the e sur surfac surfac face. fa e e.
© Mengying Liu
ANALYSIS
Surprising Discovery Could Change the Way Industry Uses Nickel Edited by Texas A&M University College Station, Texas, United States
https://engineering.tamu.edu
N
ickel is one of the most abundant elements on earth. It is hard, yet
the Center for Research Excellence on Dynamically Deformed Solids
malleable, magnetic at room temperature, and a relatively good
at Texas A&M University. Their work was published in the American
conductor of electricity and heat. Most notably, nickel is highly corrosion
Physical Society’sbPhysical Review Materialsbjournal in an article titled
resistant, which provides for a variety of uses by industry.
“Preferential Corrosion of Coherent Twin Boundaries in Pure Nickel
However, a surprising discovery by a team of researchers at Texas A&M
Under Cathodic Charging.”
University has found that nickel not only corrodes, but does so in a way that scientists least expected. The team was led by
A surprising observation
Dr. Michael Demkowicz, associate professor and graduate director in
Like a ȴnished jigsaw puzzle, materials are made of interlocking pieces.
the Department of Materials Science and Engineering, and director of
Microscopically, nickel is made ofbaggregatesbof small, tightly packed
02
N.32 - 2019 DECEMBER - ipcm® Protective Coatings
ANALYSIS
to corrode, we did, surprisingly, see visible corrosion trenches on coherent twin boundaries,” said Mengying Liu, graduate student at the Department of Materials Science and Engineering at Texas A&M and ȴrst author on the paper. “This ȴnding will help engineers predict where corrosion is most likely to begin. It may even lead to the production of metals that corrode less.”
A better understanding The team’s research not only provides engineers with vital insight into materials often utilized in situations that require corrosion resistance, but also oers a new perspective regardingbintergranular corrosion along coherent twin boundaries. For years, researchers have operated on the assumption that coherent twin boundaries resist corrosion. They have even worked to create metals that have more of these boundaries in an eort to reducebcorrosion. “This ȴnding takes decades of assumptions on metal corrosion and ȵips them on their head,” said Demkowicz. “In an eort to reduce corrosion, people have been making metals that contain as many coherent twin boundaries as possible. Now that entire strategy will have to be reconsidered.” Demkowicz believes the scientiȴc insight provided by this study may be even more important than its technological applications. “It turns out the reasoning that previously led us to believe coherent twin boundaries are corrosion resistant is ȵawed,” he said. “This work provides clues on how to improve our fundamental understanding of metal corrosion.” This work was supported by the U.S. Department of Energy, National Nuclear Security Administration, under Award No. DE-NA0003857, U.S. Department of Energy, Oɝce of Basic Energy Sciences, under Award No. crystals or grains.
DE-SC0008926 and thebNational Science Foundation.
Corrosion preferentially attacks the joints, or “boundaries,” between
Any opinions, ȴndings and conclusions or recommendations expressed
these grains. This phenomenon, known as intergranular corrosion, is
in this publication are those of the author(s) and do not necessarily
a localized type of decay that occurs at the microscopic level, targeting
reȵect the views of the National Nuclear Security Administration. ‹
the breakdown of materials at the edges of each of these boundaries, rather than at the outer surface of the material. As such, it weakens the material from the inside-out. Until now, scientists thought that one special type of boundary, known as a coherent twin boundary, was resistant to corrosion. Surprisingly, the team discovered that nearly all the corrosion in their experiments occurred precisely on these boundaries. “This ȴnding takes decades of assumptions on metal corrosion and ȵips them on their head”, said Michael J. Demkowicz. Coherent twin boundaries are areas in which the material’s internal structure pattern forms a mirror image of itself along a shared border. They occur when crystal formations on either side of an atom-wide border line up without crystallization, but can also be the result of mechanical or thermal inȵuence. “Pure nickel is mostly corrosion resistant. But when we charged it at the cathodic (passive and lowest energy) side, which is even less likely
© TexasbA&M University
disorder or disarray. These types of boundaries naturally occur during
Michael J. Demkowicz
ipcm® Protective Coatings - 2019 DECEMBER - N.32
03
Buried and submerged pipelines need external coating + cathodic protection to operate safely over the years.
ANALYSIS
External Coating + Cathodic Protection: the Safe Way to Protect Buried and Submerged Pipelines Luiz Paulo Gomes IEC-Instalações e Engenharia de Corrosão Ltda. – Rio de Janeiro, Brazil LPgomes@iecengenharia.com.br
B
uried or submerged steel pipelines are of fundamental importance to the modern world in the transportation of oil, gas, oil products,
phenomenon, completely eliminating corrosion cells. If the coating fails due to the insulation barrier deȴciency, which is always
ores, water, chemicals and other ȵuids. To ensure the integrity and long
the case in practice, the cathodic protection system complements this
life of these pipes, it is necessary to protect them against corrosion by
failure and ensures full protection of the pipeline by modifying the
using anti-corrosion protective coatings, always complemented by a
potential of the buried or submerged pipes.
cathodic protection system. The cathodic protection system functions
For example, we know that potential pipe to soil or potential pipe to
as if a perfect liner had been used in buried or submerged piping as the
water equal to or more negative than minus 0.85V, measured with the
cathodic protection current looks for coating failures and protects these
Cu/CuSO4 reference electrode, provides protection against corrosion of
locations from corrosion (Fig. 1).
buried or submerged pipes, regardless of condition of the coating.
In this way the coating failures are compensated by the cathodic protection
In order to select the most suitable type of coating and the most eɝcient
system, which injects electric current and modiȴes the potentials of the pipe
cathodic protection method (galvanic or impressed current), we need
in relation to the ground or water. As can be seen, while the anti-corrosion
to consider some important factors such as the transported product,
coating acts as an insulating barrier, cathodic protection is an electrical
the aggressiveness of the soil or water and the existence of sources
04
N.32 - 2019 DECEMBER - ipcm® Protective Coatings
ANALYSIS
Dabarti © AdobeStock
of electrical interference (electriȴed railways) and electromagnetic
water, to chemicals, to impacts during pipe transportation and installation,
interference (high voltage electrical transmission lines).
and to mechanical soil action. Other important features are high electrical
When pipelines are subjected to electrical or electromagnetic interference
resistance, adhesion to metallic material, thermal stability, ductility,
currents, which are common situations that occur mainly in long pipes
durability and ease of application.
or pipes within large cities, cathodic protection systems need to be
It is important to note, however, that it is practically impossible to obtain
complemented by an eɝcient stray current drainage system (for
all of these parameters at a high level. This is why we must always work to
electrical interferences caused by trains and subways in large cities) and
achieve the best results in order to have the best quality coating possible.
a suitable electrical grounding system (for electromagnetic interference
The main types used for buried or submerged pipelines are liquid paint
caused by high voltage transmission lines that cross or approach the
coatings (generally high-thickness epoxy or polyurethane), powder
buried pipelines, especially the long ones). Considering that the pipes are welded in the ȴeld, the welding site coatings are of fundamental importance and need to be speciȴed and executed with great care and extra attention, being that Canusa Heat
DISCRETE IMPRESSED CURRENT ANODES
Shrinkable Sleeves are the most suitable for this application (Fig. 2). For sizing of the cathodic protection system, we need to consider the surface area of the pipe in contact with the electrolyte, the electrical resistivity of the soil or water and a very important additional parameter, which is the coating eɝciency, deȴned as a percentage, which means the coverage rate oered in relation to the total area of steel to be protected. We know, for example, that the current required for cathodic protection of a buried or submerged pipe is directly proportional to its area (length x diameter) and inversely proportional to the electrolyte’s electrical resistivity and to the coating eɝciency. This means that the larger the piping area, the greater the cathodic protection current and the higher the coating eɝciency and the higher the electrolyte’s electrical resistance, the lower the current requirement. A good anti-corrosion protective coating must have good resistance to
© IEC-Instalações e Engenharia de Corrosão Ltda.
Figure 1 - Cathodic protection system protects the failures of the external coating of buried or submerged pipelines.
ipcm® Protective Coatings - 2019 DECEMBER - N.32
05
ANALYSIS
coatings (such as those applied by electrostatic processes), plastic tape
water, before and after connecting the direct current sources, which may
coatings (such as PVC, polyester or polyethylene), polyurethane foam
be current rectiȴers or batteries.
coatings (which combine corrosion protection with thermal insulation)
In order for the coating to be of the desired quality level and to guarantee
and extrusion-applied triple layer coatings with epoxy powder and two
the projected eɝciency over the expected lifetime, some care is required
layers of polyethylene or propylene. Liquid coatings are widely used for
during the storage, transport and launching of the pipes, such as always
ȴeld repair of old or damaged coatings (Fig. 3).
lifting the pipes at the ends to avoid direct pressure on the liner, use
Another type of coating, which uses coal tar or asphalt enamel, has been
protection from the sun’s ultraviolet rays (if the storage period is longer
widely used in the past but is now being less and less chosen, mainly due
than two months), plug the tubes (if the storage is for longer period,
to the serious environmental pollution problems caused by the release of
especially in medium to high aggressiveness atmosphere) and remove
toxic gases during its application.
stones so as not to damage the coating during laying.
The eɝciency of the liner directly inȵuences the current required for
Another important aspect concerns the eɝciency of the coating of welded
cathodic protection of the pipeline and it is necessary not only to specify
joints in the ȴeld, and it is recommended to always use high-eɝciency
the liner correctly but also to be careful not to damage it in the storage,
coatings in these places, with Canusa sleeves. We know that poorly
transport and release phases. The more damaged the coating the higher
speciȴed and installed ȴeld joints make it diɝcult the correct polarization
the current requirement and the higher the cost of installing the cathodic
of the cathodic protection system.
protection system.b
After trenching, in order to detect possible coating failures, it is necessary
For sizing the cathodic protection system of a particular new buried or
to inspect it using appropriate inspection techniques such as Current
submerged pipe, we recommend using the following eɝciencies for the
Mapping Method (PCM), Voltage Gradient Method (DCVG) and Potential
various types of coating used in practice:
Measurement Step by Step (CIS). b
1) New liquid coatings: 90 to 95%
Conclusions
2) New powder coatings: 90 to 97%
Buried or submerged metal pipes are subject to severe corrosive attacks
3) New coatings with plastic tapes: 70 to 90%
caused by soil, water, electrical interference (electriȴed railway lines) and
4) New polyurethane foam coatings: 90 to 97%,
electromagnetic interference (high voltage transmission lines).
5) New coatings with coal tar or asphalt enamel: 90 to 95%
Corrosion protection of these pipes is achieved, economically and
6) New triple layer polyethylene or polypropylene coatings: 98 to 99.5%
safely, by the application of protective anticorrosive coatings, always complemented by the installation of cathodic protection systems.
always recommend a current injection test by simulating a cathodic
full protection to the buried pipes, as if a perfect coating had been applied
protection system and measuring the potential pipe to soil or pipe to
to the steel pipes. ‹
© IEC-Instalações e Engenharia de Corrosão Ltda.
The coating + cathodic protection combination is the only way to ensure
© IEC-Instalações e Engenharia de Corrosão Ltda.
For old pipelines where the condition of the coating is not known, we
Figure 2 - Canusa Heat Shrinkable Sleeves to protect the ȴeld welds.
06
N.32 - 2019 DECEMBER - ipcm® Protective Coatings
Figure 3 - Care of the coating is very important for buried pipelines.
Š Adobe Stock
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BRAND-NEW
New Coatings Product Launch Applied Graphene Materials, the producer of specialty graphene
cycle. The outcome is a reȵection of AGM’s robust approach to product
materials, announces that Alltimes Coatings Ltd (Stroud, UK) a leading
development and integration into customer systems to suit speciȴc
specialist in the supply and application of protective coatings for
applications. Partnering with leading coatings companies like Alltimes
buildings, is launching its ground-breaking Advantage Graphene liquid
Coatings is a key objective of AGM, where an excellent synergy between
coating rooȴng system, with signiȴcantly enhanced anti-corrosion
our respective technical and commercial teams enables us to deliver
performance delivered by the incorporation of AGM’s graphene.
the end result of a successful product launch. We are very pleased that Alltimes Coatings and their industry customers have recognised the
The Advantage Graphene system is the result of extensive product
signiȴcant value enhancement oered by the incorporation of AGM’s
development and a rigorous testing programme, and has ultimately
graphene. This result further underscores the substantial potential of
produced a system that delivers an industry leading level of anti-corrosion
AGM graphenes in the global protective coatings industry where we are
performance, and life expectancy, for industrial and commercial roofs.
working with a number of undisclosed commercial partners”.
AGM’s graphene technology has also helped enhance other key coating
Nigel Alltimes, Managing Director, Alltimes Coatings Limited, said: “We
performance attributes and ultimately provides building contractors
believe that with the launch of Advantage Graphene, we are bringing to
and owners with a highly cost-eective solution. Due to its exceptional
market a unique and revolutionary liquid rooȴng system for our industrial
corrosion resistance performance, Advantage Graphene is being oered
and commercial customers. Without doubt, AGM’s deep understanding
with an unparalleled 30-year product warranty.
of coating technology and how best to eectively integrate graphene into
Advantage Graphene has already been promoted to targeted trade
novel chemistry, has played a major role in the successful launch of this
customers, with several industrial applications scheduled over coming
product. Early feedback from our customers has been very positive and
months.
we anticipate strong uptake as we extend the performance of our product
Adrian Potts, CEO, Applied Graphene Materials, said: “It is a great pleasure
range with graphene technology”.
to be able to announce the launch of the Alltimes Coatings Advantage Graphene product range following completion of the rigorous testing
For further information: www.appliedgraphenematerials.com
Alltimes Coatings Ltd is launching its Advantage Graphene liquid coating rooȴng system, with signiȴcantly enhanced anti-corrosion performance delivered by the incorporation of AGM’s graphene. © 7immy Getty Images
08
N.32 - 2019 DECEMBER - ipcm® Protective Coatings
BRAND-NEW
Cortec® Corporation Presents Desicorr® VpCI® Pouches with Unique Dual Action - Synergistic Effects of VpCI®/Desiccant Technologies Through research, testing, and direct knowledge of end user needs,
with VpCI-126 and Desicorr. Rings protected by yellow VCI ȴlm and silica
Cortec continues an ongoing cycle of product improvement.
desiccant appeared in adequate condition at 120 hours of testing in
Among Cortec’s wide variety of corrosion inhibiting solutions is
ASTM D-1735. Closer inspection of rings from this group showed small
DesicorrVpCI desiccant technology, whose synergistic action between
signs of corrosion starting on the top surface of the rings.
desiccant and Vapor phase Corrosion Inhibitors provides unparalleled corrosion protection.
For further information: www.cortecvci.com
Desicorr VpCI pouches are specially designed two-sided pouches containing a unique combination of desiccant and Vapor phase Corrosion Inhibitors (VpCI). These pouches are ideal for protecting
© Cortec
packaged ferrous and non-ferrous metals from corrosion. Unlike conventional desiccants, the dual function of the Desicorr VpCI pouches reduces moisture in the air (desiccant action) and provides multi-metal protection (VpCI action) within a package. In essence, the desiccant action allows the VpCI to have free access to the surface of the metal, without competition from moisture on the metal surface. VpCI action protects recessed and inaccessible surfaces and continues to provide corrosion protection even when the desiccant is fully spent. VpCI is self-replenishing to provide ongoing protection after a package is opened and resealed; the protective VpCI layer does not need removal. Pouches are extremely easy to use and can be easily inserted manually or automatically into packages. Desicorr VpCI is designed to protect products, components, or assemblies when packaged in corrugated boxes, plastic wrap or bags,
Pouches provide multimetal protection for aluminum, carbon steel, stainless steel, copper, brass, galvanized steel, silicon steel, and solder.
and wood or metal containers. Successful usages include completed assemblies, parts, components, motors, mechanical controls, precision machined or stamped parts, marine and commercial electronic
© Cortec
equipment, electrical equipment, and tools. Dessicorr VpCI Pouches are commercially equivalent to MIL-D-3464E, Type I & Type II and provide multi-metal protection. They are available in both windowed and non-windowed versions (NW). No degreasing or cleaning of the protected part is required.
VCI Film Comparison Cortec’s customer manufactures springs and small automotive components. After manufacturing and processing, automotive parts are placed in VCI bags to prevent corrosion during storage and transport. Cortec Laboratories was asked to test the eectiveness of their current VCI bags and desiccant against Cortec’s VpCI-126 bags and DesiCorr. A loosely wrapped bag of VpCI-126 and a 1/6 unit of DesiCorr showed excellent corrosion resistance in ASTM D-1735 conditions at 120 hours. No signs of corrosion were seen on the surfaces of any rings tested
The windowed version of pouches contains some indicator spheres that will change colour from yellow to green when the desiccant is fully spent.
ipcm® Protective Coatings - 2019 DECEMBER - N.32
09
BRAND-NEW
The new Sherwin-Williams solution keeps tanks and pipelines working more eɝciently with a more aesthetic ȴnish than previously available in the industry. © Sherwin-Williams
Mildew Resistant Coating Keeps Storage Tanks Looking Better Longer To enhance eɝciencies for asset owners in the oil & gas storage tank
Linings, Sherwin-Williams Protective & Marine Coatings.
segment in the EMEAI region, Sherwin-Williams Protective & Marine
Designed for use for maintenance, repair or in new construction,
Coatings has launched its new epoxy coating oering mildew resistant
Macropoxy 646MR is an ideal durable corrosion protection coating for
corrosion protection with a long-lasting, more aesthetic ȴnish.
storage tanks, ȴxed roofs, ȵoating roofs, vessels and pipelines.
The high-solids, high-build, fast-drying polyamide Macropoxy 646MR
Sherwin-Williams is tailor made to each speciȴcation, combining
primer builds on the existing proven Macropoxy 646 technology, oering
exceptional anti-corrosive performance with eective chemical resistance.
high chemical and abrasion resistance inside as well as outside of the tank
With a NACE-trained workforce specialised in corrosion control, and with
with the added formulation of outstanding mildew resistance.
more than 150 years of coatings industry experience, Sherwin-Williams
The new Sherwin-Williams solution keeps tanks and pipelines working
experts oer market-speciȴc knowledge to evaluate, recommend and
more eɝciently with a more aesthetic ȴnish than previously available in
deliver the highest level of performance coatings and linings to protect
the industry. With low Volatile Organic Compounds (VOCs), application
customer assets worldwide.
The diverse range of protective lining products oered by
can be performed on site or in shop by brush, roller or airless spray. “This coating is simple to apply without having to completely remove existing systems, and resists the growth of mildew on the exterior of tanks
For further information:
or external pipelines,” said Michael Harrison, Global Product Director for
https://protectiveemea.sherwin-williams.com
10
N.32 - 2019 DECEMBER - ipcm® Protective Coatings
BRAND-NEW
© Eu ropo
lveri
Europolveri Reaches also the Shipbuilding World
The Italian Naval Register (RINA) has certiȴed Europolveri’s powder coatings, in accordance with (MED) 2014/90/EU European Standard for the marine equipment.
The Italian Naval Register (RINA) has certiȴed Europolveri’s powder
polyester thermosetting powders in various ȴnishings and colours,
coatings with module B and D, in accordance with (MED) 2014/90/EU
have been approved for ship interiors thanks to their ȵame-retarding
European Standard for the marine equipment.
properties. This latest certiȴcation adds up to the many other that Europolveri
Europolveri’s powders DURPOL EPOXYPOLIESTER SERIES 9 and PURAL
already got in the past and that continues to maintain at present time,
POLYESTER PURE SERIES 5 are in compliance with the ȴre protection
attesting the high quality and the performance of the products placed
requirements established by the maritime equipment directive.
on the Italian and international markets.
After a meticulous check of the previously submitted documentation For further information: www.europolveri.it
and tight audits of our Quality System, the epoxypolyester and © Europolveri
© Europolveri
The epoxypolyester and polyester thermosetting powders in various ȴnishings and colours, have been approved for ship interiors thanks to their ȵame-retarding properties.
ipcm® Protective Coatings - 2019 DECEMBER - N.32
11
HIGHLIGHT OF THE MONTH
Women in Corrosion by The Australasian Corrosion Association Preston, Australia
aca@corrosion.com.au
M
odern, developed economies use technology in a vast, diverse range
academia, industry, or the education sector.
of ways, from the mathematics used to develop public-private key
“All these stakeholders face a common challenge: the need to tackle
encryption that secures internet transactions to the physics underpinning
the signiȴcant under-representation of women in the STEM workforce,
the many types of battery powering our cars, phones and computers.
because we can ill aord to under-utilise all of the nation’s available talent.
A diverse workforce, well educated in science, technology, engineering
To achieve this requires removing barriers to participation at every point
and mathematics – referred to as the STEM subjects – is required by most
of the STEM pipeline. We must create an environment where girls and
businesses, industries and organisations.
women can readily engage in STEM education and then use those skills
According to the 2019 Women in STEM Decadal Plan, prepared by the
to progress through their careers to senior levels,” the AAS report states.
Australian Academy of Science (AAS) and the Australian Academy of
In many ways, the corrosion industry reȵects this general state of aairs,
Technology and Engineering, every organisation in Australia is increasingly
being reliant on researchers – investigating both the process of corrosion
reliant on STEM skills to thrive, whether they operate in government,
and ways to control it – and practitioners managing its application.
© Shutterstock
There is a need to tackle the signiȴcant under-representation of women in the STEM workforce.
12
N.32 - 2019 DECEMBER - ipcm® Protective Coatings
HIGHLIGHT OF THE MONTH
To support its sector in particular – and industry in general – the
12 was 10 and 19 per cent. This trend was mirrored in university and
Australasian Corrosion Association (ACA) provides an extensive knowledge
VET enrolments for the same subjects. It was only in biology and health
base of best practices in corrosion management, thus ensuring all
subjects where the gender split changed for females to outnumber males.
impacts of corrosion are responsibly managed, the environment
In 2016 only a quarter of places were taken by women, in contrast to India
protected and economics improved. Through its ACA Foundation,
where more than twice as many girls were studying STEM subjects or
the organisation also provides research that is used in curriculum
China where the uptake was 76 per cent by girls.
development for schools and universities.
Furman recalls that when she was at university ten per cent of the 300
The AAS report suggests using an attract–retain–progress framework
students in the engineering subjects were girls. “However, if I remember
gives an understanding of the issues and challenges faced by women
correctly, all the girls graduated from the course,” she added wryly.
and girls in their STEM education and working lives. Attraction relates to
The ACA works with industry and academia to be a source for advice to
encouraging girls and women to pursue STEM education and careers and
support curricula design and also develop course materials to support
ensuring they see STEM as a viable and exciting career pathway.
speciȴc subjects. Furman added that she had been on the Board of the
A good education is the starting point which must provide learning and
ACA Foundation in such a role. “We looked at curriculum design and
teaching environments in which girls choose and relish all STEM subjects.
course material development that would engage students in Years 9 and
Sarah Furman, Associate Director-Advanced Materials at AECOM in
10 and so encourage them to stay on with the STEM subjects,” she said.
Melbourne was one of only three girls in Year 12 at her all-girl school
“But we also looked at the other end of education showing graduates an
studying STEM subjects. “My teachers thought my subject choice - three
idea of where/what they can do with the subjects they study.”
science and two maths - was too hard for a girl,” she said. “While I did get a lot of pressure to make alternative choices that they said would give me
The most recent census data from the Australian Bureau of Statistics
access to a broader range of subjects, my decision probably impacted
(ABS) shows that while women make up 47.5 per cent of Australia’s
the ȴnances of the school as it had to set aside a teacher for just three
workforce, they only make 16 per cent of the STEM-skilled workforce. For
students.”
companies within the technology and research sectors, the number of
However, Trish Shaw, Principal Scientist and Team Leader, Coating and
women at each more senior level steadily drops until only 28 per cent
Polymers Team, Callaghan Innovation in New Zealand, said she did not
of managerial roles are ȴlled by women. At the “C Suite” level of such
feel any pressure to change her subjects. “Ultimately, I went down a
organisations, representation decreases further with women occupying
completely science-orientated path,” she stated. “While at age 15 I thought
only eight per cent of the corner oɝces.
I may do social history and French, by the time I was in 7th form I was taking two maths, chemistry, physics and biology.”
© ACA
“While I was always in the minority – one of three or four girls in a class of 30 doing chemistry and physics – I did not perceive any pressure to change to other subjects,” Shaw added. “Also, we almost exclusively topped the classes.” Tracey Grantham, Customer Relations Manager with Adelaide Galvanising Industries, studied science and maths at school but went on to study occupational safety, health and welfare as well as adult learning before starting work in the corrosion industry. She stated: “While I could study science, at my rural high school chemistry and agriculture were deȴnitely considered male career options.” While Furman, Shaw and Grantham were in the minority of girls at their schools, they expressed similar reasons for studying STEM subjects at school. Grantham stated: “I liked the fact that the answer was deȴnitive and could be proven,” while for Furman it was “the analytical nature of the subjects and the subject’s applicability to the real world.” Similarly, Shaw felt she “liked science because it was problem solving and was always learning new things about how everything worked and how the world was put together.” Various reports by the Australian Curriculum Assessment and Reporting Authority and other bodies covering the years 2015 – 2017, show the numbers of girls electing to study engineering and computing in Year
Sarah Furman, Associate Director-Advanced Materials, AECOM.
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HIGHLIGHT OF THE MONTH
Even in disciplines where women have greater than 50 per cent
Furman added that her team at AECOM was 65 per cent female and
representation at the undergraduate and postgraduate levels, such
that many of them had been asked to be guest lecturers on courses
as in agriculture and environmental sciences, and health sciences, the
at universities in Melbourne. “In this way, girls can see other women in
proportion of women in these ȴelds signiȴcantly decreases after the early
leadership/decision making roles as well as working at the coal face within
to mid-career stage. This clearly demonstrates the problem of retention,
industry and become the role models that have been missing,” she said.
ensuring the experiences of girls and women pursuing a career in STEM
In a similar vein, Shaw’s group in New Zealand regularly welcomes local
are conducive to them remaining in a STEM career.
school groups to her workplace. “If a group of female students comes
There have been brief periods in history when the skills and abilities
through, we give them tours and get them to talk to women scientists so
of women were appreciated and used. During the Second World War,
they can see that there are role models,” she said. “We actually created an
slightly more than half of the 16,000 people working at Bletchley Park
intern position for one woman just ȴnishing a degree in engineering after
on code breaking were female and there was similar equality during the
she visited.”
United States’ space program in the 1960s with women ȴlling the majority
“In recent years, I’ve been thinking it might have been of value to have
of the “computational” roles. Unfortunately, this has not been maintained
some women supporting me,” Shaw added. “I came through an era where
and in the intervening decades, the percentage of women in Australia
I didn’t want to be treated dierently, I’m just a scientist and why should
studying science and technology at secondary and tertiary levels and then
my gender make an issue?”
using it in the workforce has steadily declined.
While it is becoming easier to get girls and young women to take up
The AAS report also points out that all employers of STEM professionals
studying the STEM subjects - anecdotally there are increasing numbers of
must curtail the attrition of women from the STEM workforce by removing
females in engineering classes across the country - keeping them within
obstacles, barriers and biases which are disincentives for women to
industry is the challenge. According to Furman, “Materials Engineering
remain in STEM careers or return to them after career interruptions.
appears to be appealing to women because it is a combination of
The hurdles faced by women arise at every stage of their schooling
scientiȴc disciplines that can be applied in the real world.”
and working career. The most common include lack of role models,
Progression is the third broad category of challenges faced by women in
stereotyping and discrimination. Both Furman and Shaw stated they felt
STEM and relates to the ability of women to move equitably to the highest
that more role models might have helped them somewhat at the start of
levels of their chosen career.
their careers.
For Shaw’s team at the New Zealand government’s innovation agency, the sta mix reȵects the ABS ȴgures with 20 per cent being women. Shaw admits this is not very high and that in the group she works in, only four
© ACA
out of 20 are women. “Out of the 20 team leaders only two are female,” she added. “However, our Chief Executive at Callaghan Innovation is female.” It will not be the simple matter of developing a new curriculum and strategy for getting women excited by the STEM subjects and the corrosion industry. It will also involve changing long-entrenched workplace attitudes. Shaw stated: “It’s important to recognise that you have to bring men on this journey so they don’t feel threatened by women in the workplace and understand that women can bring a dierent perspective and dierent approach and they don’t have to be afraid of us.” Twenty years ago, workplaces were predominantly male and those are the people that have risen to the level of making decisions but those people are now starting to retire which facilitates change. “It has been quite hard for women to have that balance and have families and have time o and still get back into their careers,” said Shaw. “In sciences and engineering I think it’s getting better now and people are recognising the value of diversity so they are making it easier for women to have those career breaks.” “When I started out in the galvanising industry, I felt ostracised on work sites where I heard comments such as ‘Don’t worry, the boys will know Tracey Grantham, Customer Relations Manager, Adelaide Galvanising Industries.
14
N.32 - 2019 DECEMBER - ipcm® Protective Coatings
what they are talking about,’” Grantham added. “Fortunately for my daughter who also works in an industry with few females, things have changed and she faces ‘speed humps’ rather than ‘hurdles.’”
HIGHLIGHT OF THE MONTH
“I do not know why society appears to think the sciences are so hard but the school curriculum seems to add to the diɝculties of subject choice,” Furman said. “I was lucky that my father encouraged me in all my choices.” Support was available at home for Grantham as well, but “as youngest of eight you had to ȴght to prove your merit.” A lot of professional associations provide great networks of knowledge. People in the industry are encouraged to attend seminars, training courses and other functions like those that the ACA hosts, all of which helps develop a ‘technical’ support network as well. Furman said she had great teachers at both primary and secondary school but also had continuing support from friends and family. “Such an on-going support network is very important,” she added. The corrosion industry seems to foster resilience and determination in its practitioners. According to Wayne Burns, ACA member and consultant © ACA
Trish Shaw, Principal Scientist and Team Leader, Coating and Polymers Team, Callaghan Innovation.
at Anode Engineering, this was exempliȴed by a particular woman back in 1989. “It seemed like we all went to hell and back in August that year,” he said. “The day before the start of our major joint conference in Surfers Paradise, the airline pilots strike started.” “This young corrosion practitioner from Perth was due to be presented
“I haven’t really noticed any barriers because of my gender, often because
with an award and was not going to let the adversity and inconvenience
I have remained focussed on achieving tasks,” Furman said. “If we do our
of the strike get in her way,” Burns added. “She was determined to be
job right, it gives a good feeling to know we are a part of something that
present to receive her award and proceeded to get across country by
might still be here 100 years from now.”
bus, rail and any other form of transport necessary and her eorts were
“We have had conversations about ‘unconscious bias’ which is also very
roundly applauded by the members of the Association.” Such tenacity is
hard to deȴne,” Shaw stated, “Whenever someone was talking about
an aspiration for young people to strive to follow.
whether you were going to give a senior role to a hypothetical person,
The journeys of Grantham, Shaw and Furman to their chosen careers may
they would always refer to this ‘person’ as ‘he.’”
have been varied, but - badly paraphrasing Monsignor Georges Lamaitre,
“I would strongly recommend that women getting into this ȴeld look for
a Belgian physicist and ordained priest in the 1920 and ‘30s - there are
and take advantage of other women in the ȴeld, don’t see it as a sign of
many paths to the truth.
weakness to look to them as mentors and sounding boards. It is easy to get isolated,” Shaw added.
The ACA’s annual ‘Corrosion and Prevention’ conference and exhibition
Like the work mentors, it is important to have support and
was held at Crown Promenade in Melbourne from 24-27 November.
encouragement at other stages of life. Parents, career counsellors and
On Tuesday 26 November, the Association held the inaugural “Women
societal behaviours and values all inȵuence the choices made by girls and
in Corrosion Breakfast,” 07:00 to 07:30, at Eureka Towers. Tracey
young women. However, girls engaging in and with STEM education will
Grantham, Trish Shaw and Sarah Furman were amongst the panellists for
not on its own facilitate retention and progression through their careers.
the event. ‹
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INNOVATIONS: PRESENT&FUTURE
Corrosion Consequences on The High Seas by The Australasian Corrosion Association Preston, Australia
aca@corrosion.com.au
W
hen pursuing suspected smugglers through the waters o northern
coastal environments ranging from hot, humid tropical to windy, freezing
Australia or rushing humanitarian aid to a cyclone-ravaged Paciȴc
sub-Antarctic. According to international standards, most of these are
island, the last thing the Commanding Oɝcer of a naval ship needs to
classiȴed as having very high to extreme corrosion severity containing
worry about is whether the hull will leak, or a critical system will fail, due to
high levels of salt laden aerosols.
corrosion.
The Royal Australian Navy (RAN) has all its water borne assets and most
Australia’s maritime industry operates in a wide variety of open water and
support infrastructure exposed to these environments. For the RAN,
©Defence Science & Technology
Adelaide class guided missile frigates (FFG), HMAS Newcastle (06) in N42 Storm Grey Polyurethane and HMAS Melbourne (05) in RAN Haze Grey Polysiloxane.
16
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INNOVATIONS: PRESENT&FUTURE
corrosion has consequences in addition to the economic ones faced by
RAN assets, including scaling the costs of a foreign navy operating similar
other organisations.
warships. According to the RAN spokesperson, the economic impact
The RAN consists of approximately 50 warships including frigates,
of corrosion and its degradation of naval assets and infrastructure is
destroyers, amphibious landing ships, submarines and patrol boats. It also
estimated to be between $135M and $650M annually, depending on the
operates minehunters, resupply vessels and hydrographic survey ships.
metric used to calculate the cost of maintenance and remedial repairs.
In addition to its vessels, the RAN’s rotary wing aircraft are integral to its
The planning now being implemented by the RAN is condition-based
operations. Generally, warships can tolerate higher levels of corrosion
maintenance which optimises maintenance costs by only intervening
causing structural damage than aircraft.
when a monitored system’s condition indicates a problem. Corrosion
All of the RAN’s vessels, equipment and structures must be protected
Prognostic Health Management (CPHM) uses these principles to predict
to minimise the impact of corrosion. Traditionally, naval maintenance
current and future corrosion conditions based on platform usage in an
was carried out on ȴxed-time schedules such as the rolling hull survey
operational environment. CPHM uses a combination of sensors and
of RAN frigates. Such programs do not allow for the impact of the actual
models to predict and plan future maintenance activities and operations.
operating environment encountered by individual vessels and its impact on operational availability.
“Moving from a time-based to a condition-based maintenance system
However, when an asset is managed eectively, the impact of corrosion
through use of environmental and corrosion sensors, allied with corrosion
can be minimised. According to a DoD spokesperson, the RAN has
prognostics and modelling, should allow targeted maintenance and more eɝcient use of limited resources,” the RAN spokesperson added. “It will
recommended by government reviews carried out in 2008 and 2011.
also allow improved scheduling of maintenance, resulting in optimum
“The plans factor the overall costs for maintenance into the acquisition
usage of platforms and equipment.”
process,” the spokesperson said. “A culture of accountability has also
Ship sta on a warship are directed to report changes in appearance or
been instituted which considers the risk-versus-cost beneȴts of deferring
obvious signs of corrosion. If sta have the relevant training, they may
preventative maintenance.”
apply corrective maintenance if it is safe and timely to do so. However,
There are a number of ways to estimate the ȴnancial cost of corrosion of
maintenance at sea or on operations is usually only carried out if it is
©Defence Science & Technology
implemented a “whole of life” management plan for its assets as
Marine hydraulics using the newly developed HVOF coatings are more resistant to biofouling and are more readily cleaned without damage to the anti-corrosive coating.
ipcm® Protective Coatings - 2019 DECEMBER - N.32
17
©Defence Science & Technology
INNOVATIONS: PRESENT&FUTURE
Deffencce e ressearchers asse se essss tthe th he e co corro rr sion sio ion an a nd n da an nti ti bio tibi fouling g pe per er orm erfor orrm rmanc an ncce of n tes esst hyd y aulic uniits ydr t coa co ted wi w th hH HV HVO V F coa co atin t ngs at the eD DS ST mari a ne exp ar expos osu osu os urre e site in Melbourrne ne, Aust Aust ssttrral ra a ia a.. a
high priority. The majority of maintenance is carried out while the ship is
Failure of a key component in ȵight could result in accidents leading to
alongside or in dry-dock in accordance with the technical maintenance plan.
loss of the helicopter and loss of life.
The RAN’s mission includes maintaining Australia’s sea lines of
Areas of naval vessels subject to continuous water immersion, such as the
communication and defending Australia’s sovereign interests. Additionally,
underwater hull, bilges and tanks, are considered critical as these areas
it undertakes humanitarian missions around Australia and the Asia
are more prone to coating failures and corrosion. Corrosion and loss of
Paciȴc region. From a long term perspective, corrosion shortens the “life
metal in tankage is a major factor in determining the life of commercial
of type” of vessels that can create a capability gap as it may be several
vessels. Freeboard areas, which are subject to continuous water spray
years before replacement vessels come into service and may have a large
while underway, and ship decks are also considered critical.
impact on the ongoing maintenance budget as the older vessels are kept for a longer time than planned.
Research into the development of specialised protective coatings
It is important to manage corrosion in the defence industry using
for military applications is supported by the Australasian Corrosion
preventative measures over both short and long timescales. Unidentiȴed
Association (ACA). The organisation works with private companies,
or untreated corrosion issues can lead to unplanned corrective
not-for-proȴt bodies and academia to research all aspects of corrosion
maintenance that can aect availability, readiness, safety and capability of
prevention and mitigations. The ACA provides an extensive knowledge
RAN vessels and rotary wing aircraft for operations, all of which result in
base that supports best practice in corrosion management, thus ensuring
signiȴcant costs.
all impacts of corrosion are responsibly managed, the environment is protected, public safety enhanced and economies improved.
Protective coatings are critical to mitigating corrosion as they form the
Several ACA members are currently engaged in a range of Defence
barrier between the metal and the aggressive marine environment.
related projects. The Chair in Electromaterials and Corrosion Sciences at
The RAN spokesperson stated that a paint speciȴcation document that
Deakin University, Professor.Maria Forsyth, and Senior Research Fellows,
details the coatings systems to be applied to every part of the ship,
Dr Katerina Lepkova and Dr Laura Machuca Suarez, at Curtin University’s
from underwater hulls, superstructure and decks to all internal areas, is
Western Australian School of Mines: Minerals, Energy and Chemical
prepared for each vessel prior to construction.
Engineering are investigating anti-corrosives such as lanthanide-based
Safety-of-ȵight is paramount for the RAN’s air assets—this demands very
ones to mitigate microbially induced corrosion and special anti-corrosive
strict inspection and maintenance programs to mitigate risk of failure.
pigments.
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INNOVATIONS: PRESENT&FUTURE
A related anti-corrosive pigment project is being undertaken by researchers Dr Sam Yang and Dr Tony Hughes at the CSIRO’s Materials Science and Engineering division, speciȴcally looking at ways to transport these pigments to defect sites. Swinburne University’s Associate Professor Scott Wade from the Faculty of Science, Engineering and Technology, is researching microbiologically inȵuenced corrosion of piping materials and mitigation options, and high velocity oxygen fuelled (HVOF) coatings for marine hydraulic applications. For many decades, the RAN employed solvent-based gloss alkyds as the topside coating for vessels but these were not very durable, often failing in as few as six months. In the 1990s, a polyurethane coating was introduced but this has since been replaced by a Low Solar Absorbing (LSA) Polysiloxane coating which has a colour-stable pigment which provides improved visible camouȵage in the waters around northern Australia. The polysiloxane also has improved thermal protection reducing the cost of cooling ships, where trials of patrol boats in norther Australian waters showed that the surface temperature of the polysiloxane coating could be as much as 15ºC cooler than traditional coatings. The development of rapid-cure, ultra-high solids, two-pack epoxy amine coatings technology oers potential advantages for the RAN, especially when dealing with complex internal surface geometries found inside sea water ballast tanks which feature baɞes with cut outs between bays and numerous longitudinal and transverse stieners to provide requisite rigidity and strength. Historically, corrosion on these edges would appear after a period in service, largely as a result of the poor edge retention of conventional coatings that were used. The latest epoxy amine coatings are applied using specialised plural component high pressure spray equipment where the two components are mixed at, or close to, the tip of the spray gun and generally require each component to be pre-heated to reduce ȵow viscosity. The coatings can be spray applied at high ȴlm build without sagging, have improved edge retention and produce very low emissions of volatile organic compounds. These coatings cure very quickly and can be walked on within a few hours, promising a fast return to service. The speciȴcation of high-performance coatings for RAN ships must be supported by rigorous quality assurance inspections. It is imperative that coatings are applied as per speciȴcation or manufacturer’s recommendations, which is best achieved through the use of independent inspectors who are required to witness the condition of the substrate and undertake measurements, such as dry ȴlm thickness at key ‘hold points’, during the surface preparation and painting processes to ensure that the environmental conditions are suitable for
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painting. These include weather conditions, substrate temperatures, and dew point. Other corrosion management technologies applicable to naval vessels and infrastructure includes research into anti-corrosive coatings, for superstructure, underwater hull, tanks and bilges as well as cathodic protection of hulls, bilges, ballast tanks, seawater piping systems. ‹
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Deck plates of marine vessels and oshore topside structures are constantly exposed to a highly corrosive environment, not to mention various forms of mechanical actions.
FOCUS ON TECHNOLOGY
Cold Bonding: An Attractive and Convenient Solution for Corroding Marine Vessel Deck Plates Jon Ferrer Belzona - Miami, Florida, USA,
belzona@belzona.com
D
eck plates of marine vessels and oshore topside structures are constantly exposed to a highly corrosive environment, not to
mention various forms of mechanical actions. These erosion-corrosion mechanisms can drastically weaken or diminish the deck strength capacity. Replacing and welding, albeit common repair solutions, are in most cases not feasible. An alternative and innovative polymeric solution can be used to reinforce deck plates by means of a cold bonding technique. This paper will focus on a case study where corrosion, excessive impacts onto the deck laydown area, and poor drainage compromised the integrity of the deck. The client sought a solution which would prevent further corrosion and reinstate larger load capacity on the deck. A cold bonding repair using 100% solids epoxy materials as adhesive was engineered for this application, after a sensible test program proved its adequacy in achieving a resilient solution.
Introduction As vessels and platform structures age, they deteriorate by corrosion and fatigue. External corrosion of the deck has become a major concern for owners and operators. Moreover, considering the various forms of mechanical wear acting upon them, it comes as no surprise that decks require to regularly be repaired or replaced. These erosion-corrosion mechanisms are important for structural strength considerations as they can drastically weaken the deck strength capacity and create unexpected halts in the operation of the vessel/platform. Some of the conventional solutions for repairing or reinstating the load capacity of a deck plate are replacement of the existing deck or welding of additional plates. Deck replacement allows to remove and replace the most corroded sections of the deck plates and replace them with new steel. This solution guarantees a brand-new deck with no overall weight gain to the deck structure, but it is very expensive and time consuming. Additionally, removing the compromised deck plates would expose the infrastructure and machinery beneath the deck, which could include, equipment from the emergency generator room and the engine room. Such unprotected equipment, when exposed to the high corrosive
N.32 - 2019 DECEMBER - ipcm® Protective Coatings
© Adobe Stock
20
FOCUS ON TECHNOLOGY
environment, can be signiȴcantly damaged, resulting in prolonged
easily be fabricated at a local machine shop to produce a bespoke plate
downtimes.
that can ȴt onto multiple geometries. However, when welding a bent
Welding additional plates to reinforce the damaged deck plates generally
plate, for instance, stresses are only generated onto the weld seam. Cold
represents the most used and recognized solution because of its low cost
bonding, on the other hand, allows a better stress dissipation as the
and quick turnaround. Since the new plates can be installed in patches,
bonding areas are larger [2].
repairs can be completed faster so that deck operations are minimally
C - Large stress bearing areas which enable a more uniform distribution
aected. Nevertheless, welding typically forms a bond around the
of applied load stress – Figure 1 displays the increase in bonding surface
perimeter of the plate and the substrate. The unbonded area can become
area accomplished with cold bonding when compared to welding. While
susceptible to crevice corrosion if welding is not continuous but rather
welding simply fuses the plate to the substrate around the perimeter, the
intermittent, allowing moisture penetration. Furthermore, this solution
adhesive covers the entire surface area uniformly. The complete coverage
requires hot work which is not always feasible or allowed in environments
of the adherend evenly distributes potential stresses [3].
with ȵammable and explosive chemicals, as sparks and hot metal can
D - Reduction of metallurgical changes compared with welding – A known
travel in any direction and start a potential ȴre and/or explosion.
consequence of welding, even with proper post-weld heat treatment (PWHT), is the formation of a macroscopic galvanic couple by producing
Cold bonding
a dierential composition within the fusion zone. Typically, this results
Another alternative solution which can be used to reestablish the load
in accelerated corrosion at the weld seams via bimetallic corrosion.
capacity of a deck plate is cold bonding. Cold bonding is a technique
Welding can also introduce heat aected zones (HAZ) including and
which consists of ȴxing a reinforcing metal plate onto a weakened
surrounding the fusion zone. These areas have experienced high enough
substrate with the use of a nonmetallic adhesive as the bonding agent.
temperatures to produce solid-state microstructural changes. Since
The reinforcing metal plate and the weakened substrates are the
cold bonding does not require hot work, the application temperature is
adherends. The bonded metal plate reinforces the damaged substrate
kept below levels that would aect the microstructure of the steel. This
and reinstates its mechanical strength. The bonding agent is applied
eectively prevents the formation of HAZ or galvanic couples [4].
onto the underside of the metallic plate and the weakened substrate
E - Easy post-assembly cleanup – Cold bonding applications can be
before both surfaces are joined together. This technique is often referred
performed in-situ without the need for specialty equipment or hot work
to as “cold bonding” since it does not require heat to bond the metallic
permits. Adhesive materials needed for the application are readily
substrates together. Avoiding hot work represents one of the biggest
available and the standardized application procedure allows personnel to
advantages of cold bonding over the aforementioned conventional
be eectively trained within hours. Once the repair is implemented, there
repairs [1]. Other advantages of this technique are as follows:
is minimal cleanup due to the limited number of tools required and no
A - Ability to join dissimilar metals – Using a nonmetallic adhesive to join
post-heat treatment.
dissimilar materials minimizes, or in most cases, prevents electrochemical corrosion between them, which could be a signiȴcant problem if welding
As any solution, there are some disadvantages related to cold bonding
is employed.
worth mentioning. Some include:
B - Ability to join complex geometries where other joining methods are
A - Temperature service limitations – One of the biggest disadvantages
not feasible – A regular problem throughout marine and other industrial
of cold bonding is the surface temperature limitation. There are a variety
environments is the degradation of components with irregular geometries
of testing methods used to ȴnd the temperature limitations of adhesives.
such as ȵanges, tees, bends and brackets just to cite a few. Typically, this
Additionally, when exposed to temperature cyclic ȵuctuations, any
creates diɝculties and limitations in the repair procedure, resulting in
dierences in thermal expansion between the adhesive and the substrate
costly modiȴcations for designed repairs such as engineered clamps.
can generate additional stress on the bond. In some extreme cases, it
Generally, metallic plates to bond or weld over damaged substrates can
could cause disbondment.
© Belzona
Figure 1 - Cold bonding and welding bonding surface areas and stress distribution.
ipcm® Protective Coatings - 2019 DECEMBER - N.32
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FOCUS ON TECHNOLOGY
B - Cold bonds are permanent – The bonded joints are generally
© Belzona
considered permanent joints since disassembly is not easy and often results in damage of the substrate involved [5]. C - More sensitive to surface preparation – Optimum adhesion of nonmetallic adhesives relies heavily on surface preparation. Substrate contamination can act as a release agent and interfere with the bonding agent adhesion. During ȴeld application, it can be diɝcult to execute
Figure 2 - Hand-applied cold bonding application.
correct surface preparation and optimum adhesion might not always be achieved [5]. D - Curing – Most adhesives require curing as the optimum bond strength is not immediately developed. Some adhesives tend to have relatively long curing times at low temperature.
© Belzona
E - Design – In some cases, the assembly requires careful design in order to minimize certain stresses. For instance, epoxy adhesives are not particularly strong under peel and cleavage stresses. They would require some ȴxtures, jigs, or engineered designs to eectively control peel and cleavage forces. As previously stated, the primary function of a nonmetallic adhesive material is to join dierent parts of an assembly and withstand the
Figure 3 - Cold bonding via injection method system.
operating conditions. Dierent adhesives can be used as bonding agents, but some applications require adhesives that can withstand harsher demanding service conditions than others without failure. The repair system must be designed so that the operational limitations of the adhesive are not exceeded within the desired lifetime of the structure to
when compared to other solvented adhesives. In addition, they are
be repaired.
capable of performing well in highly corrosive environments.
At least one manufacturer of nonmetallic adhesives recommends the use of 100% solids epoxy materials in corrosive environments. These
The use of one or a dierent 100% solids epoxy adhesive will depend on
100% solids epoxy materials can be chemically designed with superior
its required attributes. Careful consideration of the following parameters
properties over other adhesives. Some of these properties include:
will enable cold-applied reliable bonds.
A - Solvent-free materials – 100% solids epoxy adhesives are designed
A - Heat resistance – Temperature increments aect the mechanical
so there are no volatile compounds leaving the adhesive material through
performance of adhesives. Epoxy products tend to deform under a ȴxed
evaporation at normal temperature and pressure. Thus, it is safer for the
load at a speciȴc temperature known as heat distortion temperature
applicators to use, especially in conȴned spaces or small habitats.
(HDT). If an epoxy adhesive is used for operations above its HDT, the
B - Very low shrinkage during polymerization – In solvent-free
adhesion, compressive strength, tensile strength, and other mechanical
epoxy adhesives, the curing process relies on cross linking in a purely
properties can be diminished.
thermosetting process. As a result, the ȴlm thickness of the material
B - Load and stress resistance – Services conditions can include
remains almost identical before and after curing.
dierent loads and stresses such as weight, compression, tension, impact,
C - Quick return to service – 100% solids epoxy adhesives cure through
and shear among others. It is paramount to understand how the epoxy
exothermic reactions. The heat generated by the chemical reaction
will perform against these mechanical forces.
inȵuences the drying times. Quick curing indeed provides a deȴnite
C - Adhesion – This is a fundamental property as the durability of the
appeal for asset owners as enables quick project turnarounds.
repair will heavily depend on the adhesion of the epoxy adhesive. The
D - Better mechanical properties – Solvent-free epoxy materials show
material will have to endure dierent stresses while still maintaining its
greater mechanical properties when compared to solvented epoxies.
adhesion to the substrate and the metal plate.
This may be attributed to the fact that the remaining solvent within the
D - Chemical resistance – Epoxy adhesives react dierently depending
epoxy matrix can hinder the cross-linking process, aecting in turn, the
on the chemicals to which they are exposed. Some epoxy products have
mechanical properties (including adhesion) of the material.
better overall chemical resistance than others. If the service conditions
E - Excellent resistance to compression, tension, and corrosion –
include chemicals, it is important to assess the chemical compatibility of
Solvent-free epoxies have superior tension and compression strength
the adhesive with such environments.
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FOCUS ON TECHNOLOGY
At least one 100% solids epoxy manufacturer subjects their adhesive
adhesive is applied onto both surfaces making sure that the material
products to a sensible testing protocol to ensure conformance with
wets out the proȴle as much as possible. Additional epoxy material is
most stringent standards set forth by the industry. These tests not only
then applied onto both surfaces and the metal plate is forced onto the
help understand the performance of the product, but they are also
weakened substrate. Excess material exuding from the edges is removed
useful to fully characterize a material. Manufacturers decide which tests
and chamfered around the perimeter of the plate (Fig. 2).
will best highlight their product properties; then, they employ a range
The injection method, on the other hand, is preferred when repairing
of internal and external testing to verify the product performance.
larger areas. Initially, the process is very similar to the hand-applied
Some manufacturers benchmark their products to the requirements
method. The metallic plates are fabricated according to an engineered
of internationally recognized industry standards such as ISO and ASME.
design, followed by the surface preparation of the plate and the substrate
This allows asset owners to establish comparisons among dierent
to be repaired. The metal plate is designed with drilled venting holes to
products and select that which best ȴts their needs. However, most asset
allow air to evacuate as the injected product displaces it. The injection
owners are usually interested in performing further tests to simulate an
method utilizes two dierent epoxy grade materials: a 100% solids paste
environment that resembles their service conditions.
grade and a 100% solids ȵuid grade. The plates are initially dry ȴtted on
Cold bonding applications can be carried out by two methods:
top of the damaged substrate and with the use of jacking bolts, a void
hand-applied and injection. Hand applications involve the use of a 100%
cavity is created for the ȵuid product to be injected. The paste grade
solids paste grade epoxy as the bonding agent. Generally, this method
epoxy is applied and built up around the perimeter of the underside
is used for assembling small plates. Before the start of the application,
of the plate to create a dam. The paste grade material will seal the void
a plate is engineered and fabricated to meet the repair requirements.
cavity into which the ȵuid grade epoxy would be injected (Fig. 3). Then, the
Then, the surface of the weakened substrate and underside of the plate
plate is ȴxed onto the weakened substrate and the paste grade material
are cleaned and abraded to create a mechanical proȴle following the
is allowed to cure. Subsequently, the ȵuid grade epoxy is injected until
recommendations of the manufacturer. By doing this, an optimum bond
the entire dam between both surfaces has been ȴlled and the product
between the plate and the substrate can be achieved. A thin layer of
starts to ooze through the venting holes. Depending on the size, the ȵuid
FOCUS ON TECHNOLOGY
© Belzona
© Belzona
Figure 5 - Cold bonding the test panels via hand application.
Figure 4 - Results of survey performed on the deck plate. Wall thickness values are expressed in mm.
grade epoxy can be injected using either an airless spray machine, or a
the bond strength
pneumatic cartridge gun.
C - Visual determination of the eect of scraping on the steel plate joints (epoxy resin and steel interface)
Case study – The problem
D - Determination of the lap shear strength of the bond
An oil and gas platform deck plating presented signiȴcant wall thickness loss which was attributed to general corrosion, excessive impacts, and
The proposed tests were:
poor drainage. The laydown area of the deck plate originally had a wall
- Quasi-static bending test
thickness of 0.3 inch (8 mm). After inspection (Fig. 4), the average wall
- Dynamic bending test
thickness of the damaged areas ranged from 0.27 to 0.3 inch (7 to 8 mm).
- Dynamic compression test
In some areas, the minimum local plate thickness was as low as 0.17 inch
- Drag loading test
(4.5 mm). This metal loss resulted in a reduction of the laydown area capacity.
Creating the test panels
Repairs were required to prevent further corrosion and reinstate the load
Two dierent sets of panels were created for each test. One set
capacity of the deck. To avoid disruption of the platform operations, it was
comprised two plates cold bonded via hand application (Fig. 5) and
proposed to add metallic plates to the damaged areas rather than replace
the other set were plates cold bonded via injection technique. The test
the entire deck. As the lay down area was located above the engine
panels of dimensions 47 x 39 inch (1.2 x 1 m) were grit blasted to the
space, it was impossible to use welding techniques. Consequently, it was
requirements of SSPC1-SP10 (Near White Metal) with a minimum average
proposed to employ the cold bonding technique to ȴx the additional
proȴle of 3 mil (75 micron) to ensure a proper bond between the panels
plates onto the damaged areas of the deck.
and the epoxy adhesive.
In the past, epoxy resins had been used as adhesives on plate bonding
Additionally, a control sample with the same dimensions, but 0.3 inch (8
applications. However, there was no historical evidence of an adhesive
mm) thick was fabricated. The control samples were designed to replicate
used in a similar environment. Thus, it was required to test the adhesive
the conditions of a new deck.
for toughness and resilience to the rigors of the laydown area.
Testing the panels Test program
A. Quasi-static bending test
The objective of the program was to perform dierent tests which would
The test panels and the control panel were subjected to 3-point
determine the feasibility of the proposed cold bonding solution. The
quasi-static test to determine their bending properties. The test consisted
testing protocol included:
of inducing bending moments by subjecting the panel assembly to
A - Determination of the elastic boundaries of the repair plate and visual
increasing loading at the top center point, while being supported
inspection of the eects of a load against the bond
underneath at the two edges. (Fig. 6). The load was incremented
B - Determination and visual assessment of the eect of impact forces on 1
24
N.32 - 2019 DECEMBER - ipcm® Protective Coatings
SSPC The Coatings Society, 800 Trumbull Drive, Pittsburgh, PA 15205, USA
FOCUS ON TECHNOLOGY
© Belzona
the panel deformed plastically. When it was at the maximum elastic deformation, the plate had a stiness of 1.88 lbf/in (0.33 kN/mm). The test panels were able to deform elastically with loads up to 6,744 lbf (30 kN) and showed a stiness of 5.14 lbf/in (0.9 kN/mm) under that load. The graph demonstrates that the test sample (red line) achieved greater load bearing strength (area under the curve) than that of the control sample (blue line) for the same ultimate deȵection. This proved that the bond is not the weakest link and actually enables the test sample to deliver consistently and reliably twice the strength of the single control sample. The two bonded plates acted as if they were indeed one plate twice as thick as the single plate. B. Dynamic bending test Figure 6 - Schematic of quasi-static bending test.
The dynamic bending test uses the same 3-point bending setup (Fig. 8) as the quasi-static test. The only dierence is that this test, uses a 1-ton hemispherical impactor to deliver 4,425 in-lbf (500 J) of input energy. The impactor is dropped ten times from a height that would allow to deliver
© Belzona
the desired input energy in every impact. The objective of this test was to visually inspect the sample for possible failures such as cracking and/or delamination. Overall, the results showed the test panels were able to withstand all ten impacts without suering from catastrophic failure. The bonded plates only suered a 0.08 in (2 mm) permanent deformation. The control sample, on the other hand, seriously buckled when the ton weight was dropped the ȴrst time, resulting in a 4.52 in (115 mm) deȵection. Cracking of the bond line did occur at the impact zone. However, this fact did not detrimentally interfere with the overall performance of the bonded sample. C. Dynamic compression test
Figure 7 - Quasi-static deȵection load for the control sample and the test sample.
The dynamic compression test uses the same hemispherical impactor as the dynamic bending test, but the panels rest on a ȵat and hard surface (Fig. 9), thereby subjecting them to compressive forces. The force was exerted 1 in (25 mm) away from the edge of the plates, to determine its
until either the maximum load was reached or the deȵection limits
potential damage around the edges. The impactor was dropped from
were reached. It was determined that for the test the maximum load
the same height as that set for the dynamic test so that the same input
and deȵection limits were 11,240 lbf (50 kN) and 4.5 inch (115 mm)
energy was generated. It was decided to conduct this test solely on the
respectively.
bonded panels since the control panels would have not shown signiȴcant
Upon completion of the test, it was visually conȴrmed that the two
ȴndings.
metallic plates did not separate immediately after the forces were applied.
The results from this test conȴrmed that some delamination occurred
Instead, the assembly distributed the bending forces across the bonding
at the point of contact and spread out up to 2 in (50 mm) either side
area and both plates and the bond uniformly distorted retaining the
with repeated impact compression in the same location. However, the
bond line. This demonstrated the retention of intact bonds between both
adhesive did not show signs of cracking.
metallic plate interfaces. The numerical results for the test panels and the control panel are
D. Drag loading test
illustrated in the graph in Figure 7. The control panels had a maximum
The objective of this test was to drag a 1-ton load over the test plates
elastic deformation with a load of 3,372 lbf (15 kN), beyond which
and observe how they behaved and responded to the load. The load was
ipcm® Protective Coatings - 2019 DECEMBER - N.32
25
© Belzona
© Belzona
FOCUS ON TECHNOLOGY
Figure 8 - Schematic of dynamic bending test.
Figure 9 - Schematic of dynamic compression test.
applied through a square bearing pad with radiused edges, to eliminate
surfaces. Repeated impact loads did cause delamination in localized
the possibility of crack initiation.
areas, especially when the impact was at the edge of the plates. However,
As the test concluded, no failure or change was observed in the integrity
the impact applied to the test plates was extreme and concentrated,
of the epoxy adhesive. There was no delamination, cracking, or softening
and was considered to be much greater than what the deck or laydown area would be exposed to on a day to day basis. Thus, signiȴcantly less
after the load was dragged over the test plates.
delamination would occur in-situ.
Results
It was then concluded that the cold bonding solution would be the most
When compared to the control plates, the test plates bonded with the
suitable to repair and reinstate the load capacity of the laydown deck. The
100% solids epoxy adhesive were able to withstand greater static loads
solution was considered robust enough to endure the rigors of the deck
and higher impact forces before failure. The cold bonded plates also
operations.
showed excellent resistance to heavy items dragged across their entire © Belzona
© Belzona
Figure 10 - Paste grade material being applied around the perimeter of the plate.
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N.32 - 2019 DECEMBER - ipcm® Protective Coatings
Figure 11 - Installation of the injecting ports and the splitter block.
© Belzona
Figure 12 - Cold bonded application completed.
FOCUS ON TECHNOLOGY
© Belzona
Applying the solution Although both cold bonding hand-applied and injection application methods demonstrated similar results during testing, the manual application method was deemed impractical for such a large application. Therefore, dierent injection methods were tried out for ease and suitability. After dierent trials, the following application method procedure was implemented: 1. Design: Metallic plates were constructed as per design. Several holes were drilled and threaded to serve as injection ports for the 100% solids epoxy adhesive. Additional holes were also drilled to serve as ventilation ports. 2. Surface Preparation: The metallic plates and the laydown deck area were abrasive blasted to achieve a surface cleanliness of SSPC-SP10 (Near White Metal) with an average anchor proȴle of at least 3 mil (75 micron). 3. Jacked bolts were installed to act as shims to ensure the plates were leveled when placed on top of the laydown deck area. 4. The paste grade epoxy product was mixed in accordance with the
Figure 13 - Laydown deck area back in service after cold bonded solution was applied.
manufacturer’s instructions and applied with a short-bristle brush around the perimeter of each plate. Additional product was used to build a thicker layer which would limit the void cavity into which the ȵuid grade epoxy would be injected (Fig. 10). 5. The plates were then placed above the damaged area. The plates were
to ensure that the application was carried out in accordance with the
lowered until the excess product exuded around the perimeter of the
manufacturer’s best practices. Additionally, the manufacturer’s personnel
plate and the jacking bolts reached the bottom of the void cavity or dam.
inspected the application to verify that mixing, application, and curing
6. The paste grade epoxy was then allowed to cure in accordance with the
were in conformance with the job speciȴcation. The application was
manufacturer’s recommendations.
completed successfully (Figs. 12 and 13), and no failures or complaints
7. The jacking bolts were removed and the injection equipment was
have been reported ever since.
installed using a splitter block (Fig. 11). 8. The 100% solids ȵuid grade epoxy was mixed according to the
Conclusions
manufacturer’s recommendation and poured into the single component
Several conclusions can be drawn from this article:
airless spray hopper. The spray nozzle was connected to the splitter block
- Cold bonding with the use of 100% solids epoxy adhesives is an eective
and the ȵuid epoxy was then injected until the dam was ȴlled. This was
and proven solution when conventional repairs such as welding and
conȴrmed by the product exiting through the ventilation ports. Injection
replacement are not feasible. Cold bonding allows to repair equipment or
ports were capped with a bolt as the adhesive reached them.
assets in situ, with no heat, and in an easy and safe manner.
9. The ȵuid grade epoxy was then allowed to cure in accordance with the
- The testing programs provided demonstrable evidence that cold
manufacturer’s recommendations. The ventilation ports were removed,
bonding is suitable for the rigors of normal laydown area operations.
and the application was completed.
- This method oers the best compromise between cost and performance when compared to deck replacement and welding additional plates to the
The manufacturer’s personnel carefully trained the application crew
deck. ‹
REFERENCES Nguyen, N. (2012). Micromixers: Fundamentals, design, and fabrication. Oxford: Elsevier/William Andrew. Mallick, P. (2016). Materials, design, and manufacturing for lightweight vehicles. Place of publication not identiȴed: WOODHEAD. Callister, W. D. (2007). Materials science and engineering: An introduction. New York: John Wiley & Sons. Davis, J. R. (2006). Corrosion of weldments. Materials Park, OH: ASM International. Campbell, F. C. (2007). Manufacturing processes for advanced composites. Oxford: Elsevier.
ipcm® Protective Coatings - 2019 DECEMBER - N.32
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FOCUS ON TECHNOLOGY
A New Shot Blasting Plant for Higher Paint Adhesion on Isoplus Mediterranean’s Oil & Gas Pipelines Barbara Pennati ipcm®
I
n the multifaceted and complex ȴeld of surface treatments, ‘added
feature and an added value oered to its customers and users all
value’ can have dierent meanings: a unique and high-quality
over the world (ref. Opening photo). “Isoplus Mediterranean was
aesthetic ȴnish, attentive and complete service, or competitive delivery
established in 2009 and it belongs to the Isoplus Group, which has
times. Very often, added value is actually the combination of all these
twenty oɝces worldwide and whose core business are bar-based and
factors. However, corrosion protection is taking on an increasingly
ȵexible pre-insulated pipelines,” explains Fabio Zen, the plant director
crucial role, along with the ability of companies to guarantee longer
of Isoplus Mediterranean. “Isoplus Mediterranean stands out from the
service life of products even in sectors where anti-corrosion treatments
rest of the Group due to the choice it made in 2013 to add corrosion
are not normally required. The importance of corrosion protection is
protection services to its district heating business. This was based on
certainly not something new: anyone working in this ȴeld knows how
the knowledge and experience of our current management, which have
crucial it is, both since it ensures the durability of assets and because
enabled us to develop an actual separate division, ultimately making
all other factors, especially aesthetics, depend on its eectiveness.
Isoplus Mediterranean the only company in the Group to oer this
In the heavy-duty industry, including the naval, oshore, energy,
service,” says Zen.
and infrastructure sectors, all with particularly harsh environments,
The ȴrm installed its ȴrst plant to protect oil & gas pipelines in 2014;
corrosion protection is perhaps the added value par excellence.
since then, it has revamped it a few times. In order to guarantee
Isoplus Mediterranean (Villamarzana, Rovigo, Italy) has made the
better anti-corrosion paint adhesion and mechanical protection for its
protection of its pipeline for the oil & gas sector a distinguishing
pipes, Isoplus has recently installed a shot blasting system provided by © ipcm
Opening photo: Isoplus Mediterranean specialises in the application of protective coatings for pipelines intended for the oil & gas sector.
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FOCUS ON TECHNOLOGY
Figure 1 - Raw pipes ready to be treated. © ipcm
OMSG-Oɝcine Meccaniche San Giorgio SpA (Villa Cortese, Milan, Italy),
optimal shot blasting operation by preventing the pipe’s humidity from
a company specialising in the design and construction of shot blasting,
acting as an adhesive for the media, thus creating a substrate that
sand blasting, and shot peening systems.
would undermine the quality and resistance of the coating.” “After heating, we shot blast the external surfaces of the pipes in
The production flow
two plants: the ȴrst one removes any rust layer with a blast cleaning
“Isoplus Mediterranean specialises in corrosion protection treatments.
process, whereas the second one creates the right roughness proȴle to
We are able to coat pipes for downstream, middle stream, and
favour optimal coating adhesion,” says Zen.
upstream processes in the oil & gas sector, treating tubes up to 24
“We installed the latter in July 2018: it is an OMSG SANDERPIPES 80 2-7
metres in length and with diameters up to 26 inches,” states Fabio Zen.
plant (Fig. 2) equipped with two centrifugal turbines with an installed
“Our production ȵow is totally automated. It starts with the reception
power of 75 Kw each, arranged longitudinally in the lower part of the
of the material and the ȴrst cleaning phase, if we ȴnd any grease
machine. This means that the distance between the turbines and the
residues on it (Fig. 1). If the pipe is clean, it goes directly to the heating
surface to be treated is constant, allowing us treating any diameter and
station: the tube must have a temperature exceeding the air dew point,
ensuring that the ȵow of media always hits the workpiece (Fig. 3).”
in order to obtain an optimal coating. This enables us to perform an
The shot blasting tunnel passages are shielded to minimise media
© ipcm
Figure 2 - OMSG’s SANDERPIPES 80 2-7 shot blasting plant.
© ipcm
Figure 3 - A pipe after shot blasting.
ipcm® Protective Coatings - 2019 DECEMBER - N.32
29
FOCUS ON TECHNOLOGY
© ipcm
spillage through a series of special, easily removable curtains and with a sealing element that can be quickly replaced when the part diameter changes (Fig. 4). After hitting the surface to be treated, the metal grit it is collected by a screw conveyor placed on the bottom of the booth to be recovered. Then, the tube is reheated to a temperature of 230 °C (Fig. 5) to be coated. “With conventional plants, paint is applied and then the component enters the oven for the curing phase. In our work ȵow, the same amount of energy normally provided by an oven is transmitted by the tube itself: as it is heated before the paint application, is able to change the state of the applied material, thus favouring the crosslinking of the coating,” explains Fabio Zen. “Combined with the shot blasting operation, this process ensures optimal paint adhesion and enables us to apply thicknesses up to 800 microns, according to customer speciȴcations (Fig. 6).” The company uses thermosetting powder coatings supplied by AkzoNobel, Axalta, Jotun, and 3M. “The line is U-shaped and about 250 metre long. A cycle lasts about an hour,” says Alessandro Travaglini from the HSE department of Isoplus Mediterranean. “The coating application is followed by a cooling phase (Fig. 7), quality control, marking, and the ȴnal preparation of the workpieces for storage or shipment.” Figure 4 - The entrance to the shot blasting tunnel.
© ipcm
Figure 5 - Before entering the spray paint booth, the pipe is heated up to a temperature of 230 °C to foster the curing of paint.
30
N.32 - 2019 DECEMBER - ipcm® Protective Coatings
FOCUS ON TECHNOLOGY
Conclusions “When we installed our production line dedicated to oil & gas pipes, it was equipped with just one shot blasting system both for the cleaning and rust removal operations and for the surface roughening one for better paint adhesion,” states Fabio Zen. “Our need for higher productivity led us to install a second in-line shot blasting machine, thus separating the cleaning phase from the surface preparation one. Moreover, since we treat pipes with dierent sizes, we needed a system guaranteeing not only maximum ȵexibility but also optimal performance regardless of the tubes’ diameter. We already knew OMSG and, in particular, Ennio Tombetti, its general manager, with whom we have had a relationship of collaboration and trust for several years now. Also thanks to the experience gained in the pipe sector by CARLO BANFI, a long-standing competitor of OMSG that was recently acquired by the Villa Cortese-based Group, they immediately understood our needs. The project they presented to us was the most suitable solution: this is why we chose a SANDERPIPES machine.” “The shot blasting system was installed in July 2018. After more than one year, we are very pleased with it: it does not only favour optimal coating adhesion, but it also guarantees perfect mechanical protection,” states Zen. “Finally, the relationship of trust established with OMSG, as well as the quality of their products, led us to choose another shot blasting plant supplied by them to replace the one currently used for blast cleaning our pipes. It will be installed in the early months of 2020.” ‹
Figure 6 - The application of thermosetting powder coatings. © ipcm
Figure 7 - The cooling phase after coating.
© ipcm
ipcm® Protective Coatings - 2019 DECEMBER - N.32
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SUCCESS STORIES
The Evolution of High Velocity Thermal Spray: From Shop Applications to Mission Critical Equipment Protection © IGS
Back in the 1995, high velocity thermal spray was used for specialized applications in aircraft components, valves and other similar equipment.
B
ack in the 1995, high velocity thermal spray was an established
gas stream was the ȴrst piece of the puzzle. This technical development
technology in a highly controlled shop application environment. It was
delivered a surface technology that worked well with commonly used
used for specialized applications in aircraft components, valves and other
welding materials in high temperature corrosion environments such as in
similar equipment. Users of the technology started to ask whether it could
the Pulp&Paper and Coal Power sectors of the time.
be eectively applied in the ȴeld, to existing ȴxed assets in-situ. Field technology was also present at the time, however, it was a dierent
New hurdles
class of technology. Twin wire arc spray (TWAS) or thermal spray
At that stage IGS, with key clients, was exploring the wider utilization of
aluminium (TSA), are both low velocity thermal spray technologies that are
the technology into other industry sectors such as the upstream O&G
not able to produce reliable coatings to serve in critical erosion/corrosion
industry. They soon discovered that spraying o-the-shelf alloy feedstock
environments in ȴxed assets such as process vessels, towers, columns
materials using a high velocity process, produced particles that oxidized
or power boilers. The existing high velocity thermal spray equipment and
in ȵight creating an applied microstructure with permeability pathways
technology couldn’t be taken into the ȴeld eectively or economically.
for corrosion. While this wasn’t an issue for high temperature erosion applications, it was a fundamental problem for environments with corrosive
Solution identified
media e.g. Chlorine or Sulfur, among other corrosive substances (Fig. 1).
Around 1995 a handful of engineers addressed that problem and took high velocity thermal spray technology into the ȴeld. It was successfully
Material development
deployed in the downstream oil and gas industry, originally in South
Signiȴcant Research and Development work was then undertaken by
Africa, and in the late 1990s this technology went global, being adopted by
IGS in the early 2000s into developing new high velocity thermal spray
multinational energy corporations.
feedstock materials, which would control the alloy integrity during the
High Velocity Thermal Spray (HVTS), also known as the High Velocity Alloy
application process. This way the applied microstructure would be ȴt for
Cladding, has continued to evolve. Atomizing the wire in a supersonic
the service environment of the asset. The R&D project focused on the
32
N.32 - 2019 DECEMBER - ipcm® Protective Coatings
SUCCESS STORIES
© IGS
© IGS
Figure 1 - Magniȴed low velocity TS microstructure permeation by corrosive media.
Figure 2 - Protecting boiler water walls with HVTS.
permeability of the applied high velocity thermal spray microstructures,
be produced in a ȴeld environment. For assets, such as process vessels,
assessing the resistance of the applied materials to permeation by
towers and columns, organic coatings started to gain acceptance, but
aggressive/corrosive ȵuids, the shape of the deposited particles being
the results were varied and, at times, inconsistent. Complex curing
sprayed and controlling residual stresses.
mechanisms, strict application procedures and propensity to mechanical
Following development of bespoke feedstock alloys, high velocity thermal
damage made operators look for more reliable, robust, longer lasting
spray would no longer be a shop-only solution when long-term reliability
solutions, while avoiding the costs and time typically associated with
was essential. It has now become a surface technology that could be
in-situ weld metal overlay (Fig. 3).
eectively deployed as a lasting corrosion barrier in the ȴeld, during
To minimize turnaround time and extend asset life, Upstream and
shutdowns and turnarounds, reducing critical path and ensuring lasting
Downstream operators adopted the High Velocity Thermal Spray
reliability in the most arduous operating environments.
technology, successfully deployed across the globe.
Success where others have failed
The future of high velocity alloy cladding
As the adaptation of this technology continued to grow, O&G (both
The development of this technology is still ongoing, especially in
Upstream and Downstream), Petrochemical, Biomass and Waste to
new areas, such as the Waste to Energy and Petrochemical markets.
Energy plant operators started to recognize it as an optimum
Developing new processes, experimenting with new sources of fuel and
erosion/corrosion barrier to protect their ȴxed assets’ parent metal
utilizing waste as a fuel source is an important next step in our global
(Fig. 2). An example from a Swedish Energy company details the
sustainability movement. New materials and technologies, however,
performance of this solution over the years.
present a unique challenge for designers and operators in terms of unexpected and accelerated erosion/corrosion. Proven and robust surface protection solutions, which can be deployed in the ȴeld within
Another important piece of the puzzle was to design the application
turnaround schedules, are therefore seen as a welcome alternative to
equipment in such a way that “an appropriate corrosion barrier” could
repeated equipment replacement. ‹
© IGS
Lab versus field
Figure 3 - Process vessel problem areas due to failed prior protection: corrosion, pitting, cracking on a weld.
ipcm® Protective Coatings - 2019 DECEMBER - N.32
33
Future. Delivered. Get tickets > www.stocexpo.com
Connect, inspire and learn at the world’s leading bulk liquid storage event. 10-12 March 2020 Rotterdam Ahoy
© Adobe Stock
SPECIAL ON PROTECTIVE TECHNOLOGIES FOR BRIDGES, HIGHWAYS, INFRASTRUCTURES
36 ANALYSIS Polymer modiȴed cementitious coatings on concrete to control chloride-induced corrosion of steel rebars
42
Zinc spray galvanising: the preferred choice against the corrosion of steel bridge structures
44 BRAND NEW 47 HIGHLIGHT OF THE MONTH RICS: the growth opportunities and critical issues of the Italian infrastructure market
48 INNOVATIONS LUMIFLONTM resins for bridge coatings
54 HIGHLIGHT OF THE MONTH Dynamic infrastructure implements deep AI technology to prevent bridges and tunnels from collapsing
56 INNOVATIONS Perfect team for eco-friendly corrosion protection systems
ipcm® Protective Coatings - 2019 DECEMBER - N.32
35
SPECIAL ON PROTECTIVE TECHNOLOGIES FOR BRIDGES, HIGHWAYS, INFRASTRUCTURES
ANALYSIS
Polymer Modified Cementitious Coatings on Concrete to Control Chloride-Induced Corrosion of Steel Rebars Fabio Bolzoni, Andrea Brenna and Marco Ormellese CMIC G. Natta Department - Politecnico di Milano, Italy
fabio.bolzoni@polimi.it, andrea.brenna@polimi.it, marco.ormellese@polimi.it
Introduction Corrosion of carbon steel reinforcements may occur because of concrete carbonation, i.e. the reaction of atmospheric CO2 with
cement paste that lowers pH, and by the presence of chlorides in concentration higher than a critical level, that is generally
considered in the range of 0.4-1% by cement weight for concrete structures exposed to atmosphere [1]. Corrosion prevention is primarily achieved in the design phase, by using high quality concrete and adequate concrete cover. Additional prevention methods, as inhibitors, coating, corrosion resistant rebars of cathodic protection, are adopted when severe © Politecnico di Milano
environmental conditions occur as well as on structures requiring very long service life. Concrete surface treatments are of great interest for protection of reinforced concrete structure as an alternative to more expensive preventative techniques, as well as in rehabilitation. Nowadays various surface treatments are available, suitable for maintaining their protectiveness for long-time and for a good service life, providing that a proper application and an adequate maintenance are assured [1-2]. Four main classes of surface treatments are available: a) organic coatings that form a continuous ȴlm; b) hydrophobic treatments that line the surface of the pores; c) treatments that ȴll the capillary pores; d) cementitious layers. Their eect is twofold: they reduce the permeability of aggressive agents in concrete and they decrease the water content of concrete with the resulting decrease of concrete electrical conductivity and corrosion rate. PoliLaPP, Laboratory of Corrosion of Materials “P.Pedeferri” (Politecnico di Milano) studied the long-term eect on chloride-induced corrosion of polymer modiȴed cementitious
Corrosion of carbon steel reinforcements may occur because of chloride penetration.
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N.32 - 2019 DECEMBER - ipcm® Protective Coatings
mortars applied on concrete surface [3]. These coatings have good adhesion, ȵexibility low elastic modulus and a considerable crackbridging ability. Furthermore, they show low water permeability and
ANALYSIS
an adequate vapour transpiration to avoid high pressures at the concrete/coating interface, which can induce cracks or breaking of the coating [4-5]. On the contrary, there is a lack of data about long-term behaviour, only few papers report some of these results. In a previous paper, water absorption, water vapour permeability and chloride stationary diusion were investigated [6]. Results conȴrmed: • A strong reduction of water content and chloride penetration into concrete under wet and dry condition. • Due to the good water vapour permeability, coatings are also able to reduce signiȴcantly the water content in external exposure. • The protective eect is improved when the polymer-to-cement ratio increases. This paper is focused on the eect of two commercial coatings, with dierent polymer/cement ratio, on chloride-induced corrosion. More than 15 years exposure test were carried out by
© Politecnico di Milano
monitoring corrosion potential, corrosion rate and chloride proȴle.
Experimental Laboratory tests were performed on reinforced concrete specimen coated with two commercial cementitious mortars (coating thickness about 2 mm), modiȴed with the addition of acrylic-based polymer, with a polymer-to-cement (p/c) ratio of 0.35 and 0.55, respectively. Coatings were applied on reinforced concrete specimens (7·16·25 cm, Figures 1a-1b) cast with cement type CEM II A/L 42,5R (according to EN 197/1) and crushed calcareous aggregates with 10 mm maximum size (Zandobbio Quarry – BG, Italy). Water/cement (W/C) ratio was 0.5. Concrete mixture proportion is reported in table 1. Carbon steel bars with 10 mm diameter were used. Concrete cover was 2 cm. The two commercial coatings were applied on the brushed concrete surface after two months of concrete conditioning at
© Politecnico di Milano
Figures 1a and 1b - Reinforced concrete specimens.
20°C and 50% relative humidity. Concrete specimens were exposed to ponding cycles, each consisting of one week wetting with a 5% sodium chloride solution (almost 30,000 mg/L chloride ions), and two weeks drying. The test solution was placed in a plastic box ȴxed on the top of the sample. Steel reinforcements corrosion was monitored by open circuit potential (Ecorr) measurement with respect to an external saturated copper sulphate reference electrode (CSE, +0.32 V SHE) and by
Table 1 - Concrete mix design and mechanical properties.
Cement content (kg/m3)
300
Water/cement ratio (w/c)
0.5
Aggregates (kg/m3)
2000
Plasticizer (kg/m3)
4.5
28 days compressive strength (MPa)
46
linear polarization resistance (LPR, in ȡ·m ) measurement [7]. 2
Corrosion rate (CR, PA/year) has been estimate as follows: Eq. 1
CR = 1.2 · B / LPR
where B is the Stern-Geary coeɝcient (related to anodic and cathodic Tafel slopes) which assumes approximately a value of 26 mV for steel in active or passive condition, respectively. LPR
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SPECIAL ON PROTECTIVE TECHNOLOGIES FOR BRIDGES, HIGHWAYS, INFRASTRUCTURES
© Politecnico di Milano
Figure 2 - Free corrosion potential of rebars in concrete subjected to accelerated chloride ponding.
measurement was carried out applying a potential scan in the range ±10
Corrosion monitoring
mV with respect to Ecorr with a scan rate of 10bmV/minute.
According to ASTM C876 [8], for reinforced concrete structure exposed
Chloride proȴles into concrete were determined on 3 cm diameter cores
to atmosphere the probability of rebar corrosion is negligible if free
drilled from the specimens. Cores were cut into 10 mm slices, which
corrosion potential is greater than -200 mV CSE, whereas the probability
were subsequently crushed and dissolved in nitric acid. The solution was
increases up to 90% is the potential is lower than -350 mV CSE. Then
then analysed by potentiometric titration with AgNO3.
monitoring free corrosion potential is a simple way to detect the initiation
At the end of the tests, rebars were extracted from concrete specimens
of corrosion. Corrosion is conȴrmed by the increase of corrosion rate at
for visual inspection and weight loss measurements. Weight loss has
a value greater than 2 wm/year [1].
been estimated as the dierence between the weight per unit length of
Figure 2 reports the free corrosion potential measured for about 17
rebars in contact with concrete and the un-corroded rebars. Weight was
years on carbon steel rebars embedded in not coated concrete as well
measured by an analytical balance (accuracy ±0.001 g), and rebar length
as in concrete coated with the two commercial products. Figure 3 shows
were measured by a comparator (±0.01 mm).
the values of corrosion rate.
© Politecnico di Milano
Figure 3 - Corrosion rate of rebars in concrete subjected to accelerated chloride ponding.
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ANALYSIS
INITIATION OF CORROSION p/c
Carbon steel rebars in the not coated concrete specimens showed the initiation of corrosion just after few ponding cycles: free corrosion potential drops from passive condition to -400/-500 mV
Specimen
Cycle
Time
1
3
2 month
Rebars into concrete coated with 0.35 p/c coating showed initiation
2
5
3 month
remained negligible. This can be due to the high concrete resistivity,
1
110
9.6 years
good water vapour permeability, as reported in [6]. Corrosion rate
2
53
3.4 years
specimen coated with p/c 0.35 the lowering of potential occurred
3
53
3.4 years
increased.
1
no
no
2
no
no
3
no
no
-
0.35
0.55
Table 2 - Results of corrosion monitoring of reinforced concrete with or without coating.
Q U A EXCELLENCE I T Y
®
CSE and corrosion rate increased above 10 wm/years. of corrosion after about 3.5 years. Nevertheless, corrosion rates higher than 800 :·m, as the water content is low thanks to the increased above 2 wm/year only after about 9 years. On a third only after 9.6 years, and practically at the same time corrosion rate Rebars in specimens covered by 0.55 p/c coating show passive condition even after 17 years testing: corrosion potential is almost stable at value higher than -100 mV CSE and corrosion rate is negligible. Time of corrosion initiation is summarized in table 2.
Chloride diffusion Coatings are able to reduce the chloride penetration into concrete and the eect is enhanced for the coating with higher p/c ratio (Figure 4-left). After 58 cycles (3 years 8 months approx.), the
C O R P O R AT I O N Environmentally Safe VpCI ®/MCI ® Technologies
ipcm® Protective Coatings - 2019 DECEMBER - N.32
39
© Politecnico di Milano
SPECIAL ON PROTECTIVE TECHNOLOGIES FOR BRIDGES, HIGHWAYS, INFRASTRUCTURES
Figure 4 - Chloride proȴle in specimens subjected to chloride ponding: left) comparison of coated and not coated specimens; right) evolution in time for a concrete specimen with p/c 0.35 coating.
chloride content at the depth of steel bars (20-30 mm) was only 0.09 and 0.02% (by concrete weight) in the specimens covered by the coating with
cycle, Cs is signiȴcantly lower than the value observed after 58 cycles for the uncoated concrete. For the concrete coated coating p/c 0.55, Cs is
0.35 and 0.55 p/c, respectively, compared to a chloride content of about
lower than 0.1% by mass compared to concrete even after 170 cycles,
0.26% reached after only 38 cycles in the uncoated specimens. Figure
therefore much lower than the one measured without the coating after
4-right shows chloride proȴles with time for one concrete specimen
only 4 cycles.
coated with coating p/c 0.35. As expected, at a ȴxed depth, chloride content increases with time. After about 107 ponding cycles the chloride
Critical chloride content
content is similar to the proȴle measured on the uncoated concrete only
Critical chlorides threshold was calculated taking into account the
after 38 cycles.
measured time-to-corrosion (Table 2) by using the parameters obtained
In concrete specimens coated with coating p/c 0.55 the chloride content
by chloride proȴles interpolation (De, Cs, Table 3). For concrete without
remained lower than 0.1% by concrete weight even after 107 cycles
coating, critical chloride threshold is 0.06% by concrete weight, that
(around 9 years and 4 months approx.), while after 170 cycles (13 years
correspond for the considered mix to about 0.48% by cement weight,
and 8 months approx.) only in one specimen chloride content was 0.14%
in close agreement with the values reported in literature (0.4-1% by
close to the surface (data not shown here).
cement weight [1]). In the case of coated concrete with p/c 0.35 coating,
Experimental proȴles were interpolated using the analytical solution
a value similar to the previous measured in not coated concrete was
of the second Fick’s law of diusion, valid in non-stationary condition
found for the three specimens (about 0.06-0.08% by concrete weight).
for semi-inȴnite domain. Chloride concentration C(x,t) at the depth x
Analysis at the end of exposure (p/c 0.35)
after time t can be evaluated supposing that chloride concentration
After about 14 years of exposure, the specimens coated with p/c = 0.35
at the concrete surface (Cs) is constant with time and considering an
coating were broken in order to analyse the concrete water content,
eective chlorides diusion coeɝcient (De) that does not vary with
the adhesion concrete-coating, the morphology of corrosion and the
time and space, i.e. concrete is homogeneous. Results can be obtained
corrosion rate.
only to make a comparison among the dierent tested condition and
Water content was about 2% and pore saturation close to 50%, both
not to extrapolate the corrosion behaviour on real structures. More
higher than those measured after three years of atmospheric exposure
sophisticated models of diusion should be used, being two dierent
on the same coated concrete [6]. Moreover they are close to values
materials, concrete and coating, involved in the diusion process.
measured in the uncoated concrete (W/C = 0.5) in the same exposure
Table 3 shows that in the presence of a coating, at least up to the 107th
condition. This trend can be attributed to the fact that after long time
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N.32 - 2019 DECEMBER - ipcm® Protective Coatings
Table 3 - Extrapolation of transport properties of concrete W/C 0.5 with or without coating.
p/c
Ponding cycle
De (10-8 cm2·s-1)
Cs (% vs concrete)
4
14
0.35
38
15
0.54
58
8.2
0.14
107
3.6
0.46
170
5.1
0.64
-
0.35
ponding water can overpass coating and enter into concrete, according
loss measurement. For instance, considering an eective corrosion
to the chlorides proȴle showed in Figure 4 and Table 3.
area of about 10% of the total surface of the rebar, corrosion rate will
Adhesion tests revealed an adhesion strength in the range 0.51-0.63
increase at least one order of magnitude (up to about 100 wm/y), being
MPa, similar or higher than the values measured after three years
the net anodic surface smaller than the total area. These values are
of atmospheric exposure [6]. In most cases, the failure occurred
lower than mean and maximum corrosion rate calculated for carbon
at the interface between coating and concrete. On the other hand,
steel rebars embedded in chlorides containing concrete without coating
macroscopic delamination of coatings has been observed at the edge of
after 3 years exposure.
the specimen, mainly at the bottom, while the adhesion was measured on the top surface.
Conclusions
Rebar suered severe pitting corrosion attacks surrounded by passive
The eɝciency of a polymer modiȴed cementitious mortar has been
steel surface. Weight loss test revealed a mean corrosion rate is below
veriȴed by means of 17 years corrosion monitoring:
10 wm/y, in agreement with the values calculated by LPR technique
• this coating can strongly delay chloride-induced corrosion initiation
(Figure 3). It should be pointed out that this value can be misleading:
• owing to high resistivity of coated concrete, corrosion rate is reduced
pitting corrosion is localized on small portion of surface and the eective
• the protective eect is more pronounced as the polymer content (p/c)
penetration rate is higher than the one estimated by LPR or by weight
increases. ‹
REFERENCES [1] L. Bertolini, B. Elsener, P. Pedeferri, E. Redaelli, R. Polder, Corrosion of steel in concrete – Prevention, diagnosis, repair, 2nd Edition, Wiley VCH, Weinheim, pag. 1-414, 2013. [2] EN 1504 (latest version), Products and systems for the protection and repair of concrete structures. [3] A. Brenna, F. Bolzoni, S. Beretta, M. Ormellese, Long-term chloride-induced corrosion monitoring of reinforced concrete coated with commercial polymer-modiȴed mortar and polymeric coatings, Construction and Building Materials 48 (2013) 734–744. [4] L. Coppola, C. Pistolesi, P. Zaaroni, M. Collepardi, Properties of polymer-cement coatings for concrete protection, Proc. of Fifth Canmet-ACI Int. Conf. “Superplasticizers and other chemical admixtures in concrete”, ACI SP 173, Roma, Italy (1997) 267-286. [5] L.K. Aggarwal, P.C. Thapliyal, S.R. Karade, Properties of polymer-modiȴed mortars using epoxy and acrylic emulsions, Construction and Building Materials 21 (2007) 379–383. [6] M. Ormellese, F. Bolzoni, M. Berra, T. Pastore, A. Brenna, Eect of polymer modiȴed cementitious coatings on water and chloride permeability in concrete, Construction and Building Materials, 49 (2013) 720-728. [7] C. Andrade, J. A. Gonzalez, Quantitative measurements of corrosion rate of reinforcing steels embedded in concrete using polarization resistance measurements, Werkstoe und Korrosion 29, 8 (1978) 515–519. [8] ASTM C876, Standard test method for corrosion potentials of uncoated reinforcing steel in concrete, 2009.
ipcm® Protective Coatings - 2019 DECEMBER - N.32
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ANALYSIS
SPECIAL ON PROTECTIVE TECHNOLOGIES FOR BRIDGES, HIGHWAYS, INFRASTRUCTURES
Zinc Spray Galvanising: The Preferred Choice Against The Corrosion of Steel Bridge Structures
To protect steel surfaces against corrosion in order to preserve their long-term integrity dierent techniques can be employed, such as coating, hot dip galvanising, and zinc spray galvanising through an electric arc process.
Mario Colica Colimet Srl, Rome - Italy
E
colimetsrl@gmail.com
nvironmental conditions are becoming increasingly aggressive. That is why it is essential to protect steel surfaces against corrosion
in order to preserve their long-term integrity. Dierent techniques
can be employed, such as coating, hot dip galvanising and zinc spray galvanising through an electric arc process. The latter is being increasingly used in Northern Europe, the USA and Canada. In fact, zinc spray galvanising is a simple method that consists in spraying a coating, made up of millions of zinc particles obtained with a melting operation at 419.5°C in an electric arc system, on a steel surface, previously sandblasted to an SA value of 2.5 to 3. The liquid zinc solidiȴes in contact with steel and it creates a coating with a thickness between 20 and 300 Ɖm, which protects the surface in two ways: passive (barrier), by insulating it from the external environment like a paint layer, and active (anodic/sacriȴcial), by corroding instead of
© Wikimedia
steel at a 1/10 rate compared with it (Fig. 1). This parameter allows designers to predict the coating’s lastingness before the formation of 5% rust on the structure. Compared with hot dip galvanising, the zinc spray method has several advantages: • unlimited thicknesses (the higher the zinc thickness, the higher the durability); • no risk of hydrogen embrittlement because the melted particles are applied on the substrate at a temperature of 220°C; • low environmental impact, because there are no exhausted liquids to dispose of, nor VOCs like with paints; • possibility to treat structures in all sizes; • possibility to work on site, because the system can be towed; • possibility to spray zinc and/or aluminium depending on the aggressiveness of the environment; • possibility to spray Zn/Al 85/15: a coating of 150 micron, according to AWS, U.S. Navy and DOT of New Jersey, provides 30 years of protection in most bridges exposed to wet, salt- rich environment.
42
N.32 - 2019 DECEMBER - ipcm® Protective Coatings
© Canam Bridges
ANALYSIS
In addition to corrosion protection, zinc spray galvanising (zinc metallisation) complies with the requirements of authorities Canadian Standards Association (Canadian Highway Bridge Design Code) and American Association of State Highway and Transportation Oɝcials, relating to the sliding coeɝcients of bolted connections when they are subjected to impacts, vibrations, sliding and load inversion. The sliding resistance of critical connection points depends on the friction between contact surfaces when these are subjected to shear stresses. These surfaces’ conditions are a crucial parameter in the assessment of their resistance when in operation. When designing critical connection points, the contact surfaces’ sliding coeɝcient must be known in order to perform correct calculations. Coeɝcients are known for dierent types of surfaces, but the standards do not indicate any sliding coeɝcient for metallised surfaces. Before metallisation, bridge designers generally mask the overlapping areas of contact surfaces where the ȴxing bolts are to be inserted (Fig. 2). This entails more work and additional costs, also because masks must be applied and then removed manually. The sliding resistance of metallic junction points is being studied with the aim of reducing construction costs, speeding up work, and protecting steel surfaces more eɝciently. The Research Council of Structure Connections indicates a few methods to measure the friction coeɝcient. In 2012, together with the Laval University and company Canam-Bridges, they conducted a study on the sliding behaviour of metallised metal joints by adopting varying parameters, such as: • zinc thickness from 150 to 300 Ɖm; • bolt thickness from 12.7 to 15.9 mm; • presence of small burrs around the bolt holes. The search results showed a sliding coeɝcient of 0.77, obtained for joints with 150 Ɖm zinc thickness, preloaded bolts with a maximum tension of 90%, 15.9 mm sheet thickness, and no burrs, for 1,000 hours of application. The value of 0.77 is well below the coeɝcient required by the North American Standards, i.e. 0.50 (class B). Some research studies carried out in 2014 by the Federal Highway Administration with a zinc thickness value of 300 Ɖm showed an average sliding coeɝcient of 0.78, very similar to the results obtained by the Laval University and Canam-Bridges. ‹
Figure 1 (left) - The liquid zinc solidiȴes in contact with steel and it creates a coating with a thickness between 20 and 300 Ɖm.
© Canam Bridges
Figure 2 (right) - Before metallisation, bridge designers generally mask the overlapping areas of contact surfaces where the ȴxing bolts are to be inserted.
ipcm® Protective Coatings - 2019 DECEMBER - N.32
43
SPECIAL ON PROTECTIVE TECHNOLOGIES FOR BRIDGES, HIGHWAYS, INFRASTRUCTURES
BRAND-NEW
Cortec® Leads the Way for Corrosion Protection of Concrete Potable Water Structures Reinforced concrete potable water structures are at higher risk for
© Cortec
corrosion because of constant exposure to moisture (Fig. 1). They are also limited on protection methods, because it is important not to apply dangerous substances that can leach into drinking water. Cortec solves this problem with its industry-leading portfolio of Migrating Corrosion Inhibitor™ (MCI®) products that are certiȴed by UL to meet NSF/ANSI Standard 61 for use in potable water structures1. MCI extends the service life of reinforced concrete structures by working its way through concrete pores and creating a protective molecular corrosion inhibiting layer at the level of the rebar. Cortec has developed NSF Standard 61 certiȴed MCI products for use in all phases of a structure’s life cycle.
New construction When constructing new potable water tanks out of reinforced concrete, engineers can specify MCI-2005 or MCI-2005 NS water-based corrosion inhibiting admixtures. These concrete admixtures meet all physical property and corrosion inhibiting requirements of ASTM C1582 and are very user-friendly for ready-mix suppliers. Unlike traditional calcium nitrite concrete admixtures, which tend to accelerate set time and promote more shrinkage cracking, MCI-2005 actually delays set time, which can be a side beneȴt for concrete workers (MCI-2005 NS is a normal set version for projects where a delay is not desired). MCI-2005 contains 67% USDA certiȴed biobased content and is a qualiȴed product under the mandatory federal purchasing initiative of the USDA BioPreferred Program2. It was used by a water consortium in Spain to enhance the durability of a new 1.32 million gallon (5000 m³) water buer tank and avoid corrosion issues experienced with previous structures.
Maintenance MCI-2018 and MCI-2020 provide excellent surface treatment options for existing structures that need corrosion protection with an NSF Standard 61 certiȴed product. MCI-2018 is a 100% silane sealer containing Migrating Corrosion Inhibitors. Its dual action inhibits corrosion at the level of the rebar and also repels water and blocks chloride intrusion at the concrete surface. MCI-2020 is Reinforced concrete potable water structures are at higher risk for corrosion because of constant exposure to moisture.
44
N.32 - 2019 DECEMBER - ipcm® Protective Coatings
For a full listing, visit https://iq.ul.com/water/ and enter “Cortec” in the “Company” search bar.
1 2
For more information, go to https://www.biopreferred.gov/.
eosmarketing.it
BRAND NEW
Š Adobe Stock
not a water repellent, but it provides
Š Cortec
an extra strong dose of Migrating Corrosion Inhibitors that penetrate up to three inches below the surface of the concrete within one month of application. It was used to protect desalinated water reservoirs and columns at a desalination plant after insuÉ?cient concrete coverage of rebar was discovered.
Repair MCI-2018 and MCI-2020 can also be used in repairs. They have been
When constructing new potable water tanks out of reinforced concrete, engineers can specify MCIÂŽ-2005 or MCIÂŽ-2005 NS water-based corrosion inhibiting admixtures.
shown to mitigate preexisting corrosion in reinforced concrete when tested according to the U.S. Bureau of Reclamation M-82 Standard Protocol. Interestingly, they did so starting from a higher chloride threshold than typically required for this test, showing that they are able to reduce corrosion rates independently of chloride levels. MCI-2006 NS powder admixture is an excellent option for fortifying repair mortars. In addition to providing corrosion protection to rebar directly in contact with the MCI-enhanced repair mortar, MCI-2006 NS also has the capacity to migrate to surrounding undisturbed concrete to reduce the risk of the ring anode eÎ?ect. This admixture was added to repair mortar and passivating grout when repairing a network of pipes for the same Spanish water consortium previously mentioned. For further information: www.cortecmci.com
Drive Your Edge and Certify Your Business
Š Cortec
&HUWL²FDWLRQ DQG PDLQWHQDQFH FRQVXOWLQJ VHUYLFHV ISO 9001:2015
Quality Management System
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Health & Safety Management System
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Energy Management System
MCIÂŽ-2020 was used to protect desalinated water reservoirs and columns at a desalination plant after insuÉ?cient concrete coverage of rebar was discovered. 9LD %DQ² 9LPHUFDWH 0% ,WDO\ +393346654055 - info@zetaduequality.it
SPECIAL ON PROTECTIVE TECHNOLOGIES FOR BRIDGES, HIGHWAYS, INFRASTRUCTURES
BRAND-NEW
Sherwin-Williams Chosen for Fire Protection Safety at Stunning Tottenham Hotspur Stadium Sherwin-Williams coatings were chosen for the ȴre protection of
using only the best products. We’re proud to have been involved to
steelwork at Tottenham Hotspur’s new showpiece stadium where up
ensure only the highest levels of ȴre protection measures are in place
to 62,000 fans will be seated for the club’s home games.
where the lives of people and the safety of property are at stake,” said Mark Lockhart, Sherwin-Williams UK Sales Manager.
Having examined the priorities to protect the steel structure in the
Macropoxy C400V3 epoxy zinc phosphate coating was selected and
event of a ȴre with such large numbers of people moving about,
applied after blast cleaning of the terrace steelwork, a system suitable
Sherwin-Williams experts selected FIRETEX C69 Epoxy blast primer,
for the protection of steelwork in a range of exposure environments
followed by FIRETEX FX2003 solvent-based intumescent coating with a
from C1 to C5 as deȴned in ISO12944, including buildings, car parks,
top coat of Acrolon C237 acrylic urethane sheen ȴnish.
petrochemical plants, breweries and power stations.
The Sherwin-Williams Macropoxy C123 coating was used for the surface
Projects using ȴre and corrosion protection coatings delivered
below the second synthetic pitch, achieving low curing down to 5°C. The
by Sherwin-Williams across EMEAI include London’s The Shard,
coating is easy to apply by airless spray; compatible with a wide range
Azerbaijan’s Flame Towers and the Leadenhall Building, known as The
of Macropoxy, zinc clad epoxy primers and build coats; and compliant
Cheesegrater.
with Volatile Organic Compound (VOC) standards. Steel fabricator for the project was Severȴeld.
For further information:
“This project demanded the highest speciȴcation standards for stadia
https://protectiveemea.sherwin-williams.com
© 2019 Tottenham Hotspur FC
The project of Tottenham Hotspur’s new showpiece stadium demanded the highest speciȴcation standards for stadia.
46
N.32 - 2019 DECEMBER - ipcm® Protective Coatings
SPECIAL ON PROTECTIVE TECHNOLOGIES FOR BRIDGES, HIGHWAYS, INFRASTRUCTURES
HIGHLIGHT OF THE MONTH
RICS: The Growth Opportunities and Critical Issues of the Italian Infrastructure Market edited by RICS London - UK
contactrics@rics.org
I
nfrastructure gap, cost beneȴt analysis, and public or private dilemma:
illimity Bank CEO Corrado Passera stated: “Infrastructure is a fundamental
infrastructure is a topic of daily debate in Italy. The state of the art, the
factor of productivity and growth, and therefore of employment, in every
future, and the possible tools to identify shared metrics that can facilitate
country. Italy must make up for its delay. In order to do so, various actions
the recovery and development of the sector were some of the themes
are needed: eliminating unnecessary red tape (gold-plating), discouraging
addressed during the annual RICS conference, held at the premises of
spurious appeals, reducing the resistance of aected communities
Triennale Milano on July, 11.
(NIMBY eect), and promoting adequate upstream involvement (débat publique). The most eective model for strategic infrastructure (or
The event was an occasion for discussing and exploring the growth
essential facilities) is the one implemented by Terna and SNAM, which
potential of the Italian infrastructure market, which is often the subject
should also be applied to telecommunications networks and the rail
of the national public debate. Experts and institutional representatives
network. We need a massive European infrastructure investment plan,
attended the conference. In particular, the debate was animated
funded jointly by all EU member states.”
by Gabriele Buia, President of ANCE (Italy’s National Association of
Another challenge faced by the infrastructure sector is the demographic
Construction Builders); Corrado Passera, the Minister of Infrastructure
expansion of the planet. The world population is expected to exceed 9
and Transport of the Monti Cabinet and the CEO of illimity Bank;
billion people in 2050. It is estimated that over the next 40 years more
National Infrastructure Observatory President Stefano Cianciotta; Marco
will be built than has been the case so far. Therefore, it is essential to
Daviddi, fellow of RICS and a partner of EY as the Mediterranean Leader
immediately start creating a regulated, ethical, and sustainable market
– Transaction Advisory Service; and Umberto Regalia, a Local Public
respecting individuals and the environment.
Transport Agency Past-President.
“Together with other European stakeholders in the building sector
They talked about the undergoing changes in the sector due to the
(European Construction Forum), on June, 12 RICS presented a joint
advent of new technologies, such as Analytics and Big Data, Internet of
initiative to outline the future of the construction sector in Europe: a new
Things, and Artiȴcial Intelligence. This evolution is actually aecting the
normative framework called EU Construction 2050,” said Daniele Levi
design, building, operation, and maintenance of infrastructure and it
Formiggini, Chairman of RICS in Italy. “The role of RICS in this venture will
is calling for new skills and new job roles. Italy seems to be reacting to
be crucial, in particular for the implementation in Europe of international
these developments more slowly and it ranks last compared to France,
standards, such as the International Cost Measurement Standard (ICMS),
Germany, Spain, and the UK (source: EY study Digital in Infrastructure).
which promote globally shared metrics for the assessment, classiȴcation,
EY Mediterranean Leader – Transaction Advisory Service Marco Daviddi,
and cost analysis of major works.”
said: “Connectivity concerns networks and the ȵow of people, goods,
ANCE President Gabriele Buia added: “Infrastructure is useful for
services, data, and capital. All this requires infrastructure in its broadest
the social well-being of the community. ANCE is striving to remove
sense. Without adequate digitalisation, physical infrastructure will have
all bureaucratic obstacles that hinder the expenditure of resources
and create a very limited value. Through the digitalisation resulting from
and lengthen the time required for work completion. In order to be
advances in cloud computing, big data analysis, artiȴcial intelligence, and
competitive, we must be able to carry out the works on time and with the
machine learning, infrastructure can be increasingly eɝcient, ȵexible,
right costs.” ‹
and connected. This can guarantee the rationalisation of Italy’s currently ineɝcient infrastructure system. Rationalisation and identiȴcation of priorities are two complementary aspects. In this country, still with a limited degree of digital penetration, this can be an exceptional opportunity to boost competitiveness.” As a conȴrmation of the low impact of technologies on its territory, Italy ranks 25th out of 28 countries, ahead only of Bulgaria, Greece, and Romania, in the Digital Economy and Society Index (DESI), assessing the digitalisation level of EU member states.
ipcm® Protective Coatings - 2019 DECEMBER - N.32
47
Tokyo Gate Bridge is painted with LUMIFLONTM.
© motaen.com
INNOVATIONS: PRESENT&FUTURE
SPECIAL ON PROTECTIVE TECHNOLOGIES FOR BRIDGES, HIGHWAYS, INFRASTRUCTURES
LUMIFLON Resins for Bridge Coatings TM
Rene Spier AGC Chemicals Europe Ltd. - Amsterdam, The Netherlands
lumiflon@agcce.com
Introduction
long-term aesthetic and protective performance is required are bridge
Fluorourethane coatings based on FEVE (ȵuoroethylene vinyl ether),
coatings. Steel bridges need to be protected with the best possible anti
have been used globally for over 30 years. This technology has a proven
corrosive coating technology but are also often iconic structures where
record of outstanding performance with respect to outdoor exposure,
visual appearance is of importance. Furthermore, repainting bridges is a
oering the highest standard in gloss and colour retention. Besides
cumbersome and expensive job which emphasizes the beneȴts of
excellent aesthetic performance, long time corrosion protection is
long-lasting coating systems even more.
achievable as well and therefore FEVE resins ȴnd many applications as
This article will detail the use of LUMIFLONTM coatings for bridge
part of protective coating systems. One particular application where both
applications, showing an example of a bridge coated more than 30 years
© AGC Chemicals
Figure 1 - Alternating structure of FEVE resins.
48
N.32 - 2019 DECEMBER - ipcm® Protective Coatings
INNOVATIONS: PRESENT&FUTURE
Resin
C-C Chain
KJ/mol
C-F. C-H
Property
Value
Fluorine Content
20-30 wt%
OH Value
47-170 mg KOH/g
COOH Value
0-15 mg KOH/g
Molecular Weight
Mn = 15000-100000
Speciȴc Gravity
1.4 – 1.5
Morphology
Glassy (Tg = 20-50 °C)
Solubility Parameter (cal’d)
8.8
KJ/mol
Fluoro Compound
CF3-CF3
414
F-CF2-CH3
523
Fluoro Compound
CF3-CH3
424
CF3CH2-H
447
Commodity Chemical
CH3-CH3
379
CH3CH2-H
411
Table 1 - Bond energy of ȵuoro-chemicals and commodity chemicals. [2]
Table 2 - Typical properties of FEVE resins.
ago in Japan without ever being repainted.
extreme UV resistance properties. The chemically stable and UV resistant
Coatings that passed the new ISO 12944-6 standard, category C5 (very
ȵuoroethylene units sterically and chemical protect the neighbouring vinyl
high corrosive environment) and ISO 12944-9 CX (high impact areas)
ether units. [1]
tests protocols are also shown. These coating were formulated with EU
The vinyl ether groups make FEVE polymers useable as resins for paint.
available raw materials and the testing was performed and assessed by
Without the vinyl ether groups, FEVE resins would not be soluble in
COT in Haarlem, the Netherlands, an independent research laboratory
solvent. This solubility is what allows FEVE resins to be used in a wide
certiȴed to perform industrial speciȴcation testing for the coating industry.
array of coating formulations that can be applied in factory or on-site settings. A wide range of curing temperatures can be employed ranging
LUMIFLONTM
from room temperature to 230°C. The vinyl ether groups also contribute
Fluoroethylene vinyl ether (FEVE) resins were developed in Japan in
to high gloss and allow for functional groups, like hydroxyl groups, to be
the late 1970’s and were ȴrst commercialized in 1982. FEVE resins are
incorporated into the structure. Table 2 shows typical properties of FEVE
amorphous A-B type copolymers with repeating units of ȵuoroethylene
resins. [1]
and substituted vinyl ether (Fig. 1). Unlike pure ȵuoropolymers, FEVE
As explained above FEVE resins are renowned for their extremely
resins are soluble in solvents due to the vinyl ether groups. Solvent
high durability due to the high C-F bond energy. Therefore, they
solubility transforms FEVE resins from high performance polymers into
do not degrade under the inȵuence of UV radiation from the sun.
high performance resins for coatings. [1]
Fluorourethane topcoats have been tested in both accelerated
FEVE resins have characteristics of both ȵuoropolymers and
and natural weathering. The following ȴgures show the weathering
hydrocarbons. The ȵuoroethylene groups are the strength of the FEVE
performance typical of ȵuorourethane coatings based on FEVE resins.
resin. These groups are responsible for the polymer’s high resistance
Figure 2 shows a comparison of a FEVE coating to polysiloxane and
to UV degradation. The C-F bond is very strong (Table 1). The energy of
acrylic urethane-based coatings in QUV accelerated weathering. The FEVE
this bond is higher than the energy of UV radiation at 290nm which is
coating clearly outperforms the other resins which are renowned on their
~411KJ/mol. The alternating pattern, shown in ȴgure 1, is critical for the
own in the industry for their good weatherability. Furthermore ȴgure 3
© AGC Chemicals
Figure 2 - QUV Exposure of a FEVE-based coating.
© AGC Chemicals
Figure 3 - South Florida Exposure of a FEVE-based coating.
ipcm® Protective Coatings - 2019 DECEMBER - N.32
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SPECIAL ON PROTECTIVE TECHNOLOGIES FOR BRIDGES, HIGHWAYS, INFRASTRUCTURES
© AGC Chemicals
© AGC Chemicals
Figure 4 - FEVE white coating. 1 micron of erosion after 15 years of exposure.
Figure 5 - Polyurethane white coating. 22-28 micron of erosion after 15 years of exposure.
sunlight. Under the tape the ȴlm was not damaged. The ȴlm thickness of
data clearly shows the excellent performance of the FEVE based coating
each topcoat after 15 years outdoor exposure could be compared to the
technology achieving a gloss retention of around 70% after 10 years of
original ȴlm thickness under the tape. After 15 years, the ȵuoro-polymer
exposure.
topcoat has lost about 1.1Ɖm total (less than 0.1 Ɖm/year), while the
Besides excellent gloss and colour retention FEVE topcoats also oer a great
polyurethane topcoat has lost 22-28Ɖm (about 2Ɖm/year).
beneȴt in terms of general protection of underlying substrates. Due to the
In ȴgure 6, two sections of the coating are analysed by Imaging IR
high UV resistance and lack of degradation of the resin the coating itself will
(IRT7000[3]). That measurement can detect amide (II) absorbance and
stay intact much longer than for example an acrylic urethane-based topcoat.
quantify it in comparison to the C-H band or C-F band. A chemical map
Figures 4 and 5 show ȴlm consumption for the ȵuoro-polymer coating
is generated, which shows the distribution of the amide bond through
and polyurethane coating in cross section after 15 year of exposure. A
the cross-section. The colour gradient of this map directly relates to
portion of the coating was covered with tape and thus was not exposed to
the concentration of isocyanates. In the case of the ȵuoro-polymer,
© AGC Chemicals
shows South Florida exposure of a clear and a yellow FEVE coating. This
Figure 6 - Isocyanates retention of each cross section of coats about mild light seal or irradiated surface area.
50
N.32 - 2019 DECEMBER - ipcm® Protective Coatings
© AGC Chemicals
INNOVATIONS: PRESENT&FUTURE
Figure 7 - Impedance spectroscopy.
comparing the cross-section which has been light-sealed (map A) and
degradation signs. As is demonstrated in tables 3-4 and ȴgure 9 the
the cross-section which has been exposed (map B) shows that the
paint system performed excellent after 30 years of service life. A gloss
decomposition of isocyanates is very limited. Indeed, the same intensity
retention of over 70% was measured after wiping the coating free of
in the gradient can be observed with the red colour present through
dust and dirt. Also, no rust peeling or cracking was observed. Colour
the depth of both cross-sections. In the case of the polyurethane, the
measurements could not be compared due to a change in colourimetric
protected cross-section (maps C) and the exposed cross-section (map
techniques throughout the years. However, the red colour still appears as
D) show large dierences. In the map of the exposed cross-section, the
bright as when it was applied 30 years ago.
yellow colour indicates that the isocyanate concentration is much lower in comparison to that of the protected cross-section in red. UV light has
© AGC Chemicals
induced the degradation of the isocyanate in the polyurethane coating, even at a 20wm depth from the surface. In practice this means that from a protection point of view one could use a much thinner topcoat if FEVE technology is used thus saving paint and application costs. Finally, in ȴgure 7 impedance spectroscopy is shown which demonstrates that using a FEVE based topcoat oers beneȴts with respect to anti corrosive properties as well. In the experiment a standard corrosion inhibiting primer was used. The only dierence is the topcoat technology. Also, in this study the ȵuoro-polymer based topcoat shows improved performance over polyurethane technology.
Bridge applications in Japan Ever since the development of FEVE resins by AGC in the early 80’s the Japanese road authorities have carried out performance testing and evaluations of coating systems based on FEVE resins. The outstanding durability that was found led to the mandatory use of ȵuorinated topcoats for bridges throughout Japan. The Daiichi-Mukaiyama bridge was newly build in 1987 (Fig. 8). The primer and middle coats were shop applied and the topcoat system, based on a LUMIFLONTM resin system, was applied on site. Colour and gloss measurements were taken initially and after 22 and 30 years. Furthermore, the coating was inspected for chalking and other
Figure 8 - Daiichi-Mukaiyama bridge.
ipcm® Protective Coatings - 2019 DECEMBER - N.32
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SPECIAL ON PROTECTIVE TECHNOLOGIES FOR BRIDGES, HIGHWAYS, INFRASTRUCTURES
Initial
22 years
30 years
Measured value
52.4
46.5
28.3
Retention
-
88.7%
54%
Measured value
52.4
49.9
38.7
Non wiped
Wiped Retention
-
92.5%
78%
Table 3 - Gloss retention.
Bridge coatings in Europe
Upstream side
Downstream side
Part investigated
Rust
Peeling
Crack
Brace
0
0
0
Cross Girder
0
0
0
Arch Rib
0
0
0
Brace
0
0
0
Cross Girder
0
0
0
Arch Rib
0
0
0
Table 4 - Appearance observation after 30 years.
intervals will be greatly increased. Over the total lifetime of a bridge
In Europe, most speciȴcations for bridge coatings are referring to the
the reduced requirement for maintenance and repainting will oer
ISO 12944. This standard looks at the corrosion protection performance
signiȴcant cost saving and will reduce environmental impact.
of coating systems in dierent corrosive environment classes. Currently,
Several countries in Europe require additional testing of a coating
nearly all bridge coating systems in Europe are based on polyurethane
system at an independent certiȴed testing institute before they
or poly-siloxane topcoat technology. These types of coatings can pass
are approved to be used for application on bridges. Currently FEVE
the ISO 12944 corrosion testing based on C5 and CX environments. As
based systems are being speciȴed at several rail and road agencies
these are the strictest tests within the ISO 12944, there seems to be no
throughout. A ȴrst example of this is in Italy where ȵuorinated coating
need for coating systems with an improved weatherability. However, the
systems are speciȴed by ANAS under the code: IT.CDTG.05.18. In
ISO standard only looks at the corrosion protection performance of the
Germany coatings have been tested by BAST and passed according to
coating system without considering aesthetic longevity. The aesthetics
the BLATT 87 and approval by Highways England and Network rail in
of a coating are an important factor when determining the durability
the United Kingdom is expected mid 2020. In recent years a number of
of a coating system and the amount of repainting that is needed. The
bridges in Europe has been coated with ȵuorinated resins as a result of
need for coatings with a longer life time is recognized more and more
these developments. Figures 10 and 11 show two of such examples,
in the industry, and bridge owners are therefore asking for prolonged
one in Switzerland and one in Italy.
durability (> 30 years) both on corrosion and aesthetic performance. As is shown in the following chapter, FEVE based coating systems pass
Specification testing
ISO 12944 testing for C5 and CX environments. However, because of
Recently, ISO published a new version of its 12944-speciȴcation
their improved weatherability compared to traditional coating systems
document. The new speciȴcation now includes a section on testing for
on both corrosion and aesthetic performance, the maintenance
25 years protection for the dierent corrosive environments which is
Figure 9 - Daiichi-Mukaiyama bridge inspection after 30 years.
52
N.32 - 2019 DECEMBER - ipcm® Protective Coatings
INNOVATIONS: PRESENT&FUTURE
mentioned in the 12944-6 section. Furthermore, an added section called 12944-9 now details testing for CX environment and dierent immersion classes. AGCCE decided to reformulate the Japanese commercial topcoat formulations with EU available raw materials and test these systems to the new ISO standards at the COT research laboratory in Haarlem which is accredited to perform speciȴcation testing. Two white coatings and a red coating were tested. All passed the speciȴcation testing as will be shown below. Three topcoat formulations were submitted for speciȴcation testing at COT Haarlem. Two dierent whites, which used a standard TiO2 grade (white 1) and a high durable TiO2 grade (white 2), and a red topcoat were applied. The primer and middle coat for each system was the same. © AGC Chemicals
Figure 10 - A bridge in Switzerland coated with ȵuorinated resins.
Application and testing of the full coating systems was performed at COT in Haarlem, the Netherlands. [3] Table 5 depicts the dierent coating systems. The substrates were steel panels blasted to Sa 2.5 grade cleanliness according to ISO 8501-1. Surface roughness Medium (G) according to ISO 8503-1. All three coatings systems passed the requirements for test methods showing their outstanding protective performance in the toughest environments.
Conclusion FEVE resins oer great beneȴts for use in bridge coating paint systems. The technology has a proven record of accomplishment in Japan of over 30 years performance. Furthermore, the testing carried out at COT has veriȴed the performance of coating systems formulated with EU available © AGC Chemicals
raw materials to the highest ISO 12944 speciȴcation standards. ‹
Figure 11 - A bridge in Trento (Italy) coated with ȵuorinated resins.
Coating
White 1 (dft μm)
White 2 (dft μm)
Red (dft μm)
Bonn Zinc No.20 ZHB
60
60
60
Bonnȵon primer for steel towers No.630
200
200
200
Bonn Epocoat No.30HB Grey
30
REFERENCES [1] Kristen Blankenship, “Formulation Techniques Using FEVE Resins in Waterborne and High Solids Coatings,” Proceedings of the Forty-Second Annual International Symposium of Waterborne, High Solids, and Powder Coatings Symposium, p. 251 (2015).
30
30
[2] E. Bure, “Smart Fluorinated Organic Molecules”, Molecular structure and energetics vol.3, Chap.4 pp141-191(1986) [3] Testing and application of coatings performed at: COT Haarlem,
LUMIFLONTM Topcoat
30
30
30
The Netherlands (http://www.cot-nl.com/?lang=en)
Table 5 - Coating systems.
ipcm® Protective Coatings - 2019 DECEMBER - N.32
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SPECIAL ON PROTECTIVE TECHNOLOGIES FOR BRIDGES, HIGHWAYS, INFRASTRUCTURES
HIGHLIGHT OF THE MONTH
Dynamic Infrastructure Implements Deep AI Technology to Prevent Bridges and Tunnels From Collapsing edited by Dynamic Infrastructure New York, USA
T
contact@diglobal.tech
he New York and Tel Aviv based startup Dynamic Infrastructure is
and private companies.
implementing the world’s ȴrst deep-learning solution which allows
Dynamic Infrastructure quickly creates “medical records” for every
bridge and tunnel owners and operators to obtain visual diagnosis of
bridge, tunnel and elevated highway, based on existing images taken
the assets they manage. The system provides live, cloud-based, 3D
through periodical condition inspections along the years, including
views of the bridge or tunnel and automatically alerts when changes are
images from smartphones, drones and laser scanning. The proprietary
detected in maintenance and operation conditions - before the issues
technology compares old and archived images to new ones, detecting
evolve into large-scale failures.
maintenance and operation issues, defects and anomalies. Like MRI for
With huge Opex and Capex positive impact, Dynamic Infrastructure is
humans, the 3D “medical records” serve as the basis for the alerts on
already conducting projects in the U.S., Germany, Switzerland, Greece
changes in maintenance conditions.
and Israel with dierent transportation infrastructure stakeholders.
The diagnostics can be easily accessed through a simple browser
The company’s clients operate a total of 30,000 assets, ranging from
and can be instantly shared with peers and contractors to speed
Departments of Transportation to Public-Private Partnerships (PPPs)
maintenance workȵows and increase return on investment.
Deȴcient bridges and tunnels represent a severe infrastructure challenge in the US and worldwide and their poor condition leads to life losses and millions in unplanned expenditures.
© Joseph Sohm
54
N.32 - 2019 DECEMBER - ipcm® Protective Coatings
HIGHLIGHT OF THE MONTH
The New York and Tel Aviv based startup Dynamic Infrastructure is implementing the world’s ȴrst deep-learning solution which allows bridge and tunnel owners and operators to obtain visual diagnosis of the assets they manage. © Ashlee Rezin/Sun-Times
Dynamic Infrastructure, which operates from New York, Berlin and
their lifetime. We provide actionable monitoring and alerts that can
in Israel, was founded in 2018 by Saar Dickman and Amichay Cohen.
better manage expenditures and help prevent the next collapse. We are
Dickman and Cohen collaborated with a group of industry experts in
bringing the data revolution to the decision-making process of bridges
the US and Europe who share the same vision – creating visual medical
and tunnel maintenance based on our cutting-edge imagery analysis.”
records for mega infrastructure elements, focusing on the challenging
In total, there are more than 616,000 bridges in America. Of those,
conditions of bridges and tunnels. Prior to Dynamic Infrastructure,
more than 47,000 are structurally deȴcient and need urgent repairs,
Dickman served as VP Automotive Cyber Security at Harman, a
according to a report issued earlier this year by the American Road &
Samsung-owned company, following the successful acquisition of
Transportation Builders Association (ARTBA). Americans cross these
TowerSec, his previous company, by Harman. Amichay Cohen served
deȴcient bridges 178 million times a day.
as the CEO of Carmel Tunnels and is currently acting as the COO of D.E
The average age of a structurally deȴcient bridge is 62 years. More
Highways Management, where he is responsible for an annual revenue
than 235,000 (38%) of U.S. bridges have identiȴed repair needs. ARTBA
of $350 millions, operating toll-roads and toll tunnels.
estimates the cost to make the identiȴed repairs for all 235,000 bridges
“The world faces an infrastructure crisis,” said Saar Dickman,
is nearly $171 billion. The pace of repair in 2018 slowed in comparison
co-founder and CEO of Dynamic Infrastructure. “Speciȴcally, deȴcient
to 2017, and therefore ARTBA warns that at this pace, it will take 80
bridges and tunnels represent a severe infrastructure challenge in
years to make signiȴcant repairs in America’s bridges.
the US and worldwide and their poor condition leads to life losses
Tunnels are no dierent. According to the Federal Highway
and millions in unplanned expenditures. Trying to repair America’s
Administration (FHWA) and the Federal Transit Administration (FTA),
deȴcient infrastructure without adopting new technologies will not work.
more than 350 highway tunnels have been identiȴed in the United
Technology allows you to change the equation of one dollar problem
States. About 40% of these tunnels are now more than 50 years old;
equals one dollar of solution. A single dollar of the right technology in
and approximately 5% of these tunnels already exceed 100 years of
the right place can save much more than one dollar of maintenance of
service.
a bridge.”
Therefore, according to Dynamic Infrastructure, a system of the type
Dickman continued: “Until recently, there has been no eective system
oered by the company is vital for maintaining and operating tunnels in
that can quickly and precisely identify defects in bridges throughout
America. ‹
ipcm® Protective Coatings - 2019 DECEMBER - N.32
55
INNOVATIONS: PRESENT&FUTURE
SPECIAL ON PROTECTIVE TECHNOLOGIES FOR BRIDGES, HIGHWAYS, INFRASTRUCTURES
Perfect Team for Eco-Friendly Corrosion Protection Systems Dennis Bringmann, Markus Hallack, Marion Siemens Evonik Resource Efficiency GmbH - Essen, Germany
E
coating-additives@evonik.com
xperts estimate that one-third of all iron and steel products
Corrosion requires an anode where iron is oxidized to Fe2+. Oxygen
manufactured worldwide per year are used to replace corroded
is reduced to hydroxide ions at the cathode that is located elsewhere.
structural components. The economic damage, therefore, is enormous.
Between the anode and cathode, a potential dierence exists (see
The term “resource eɝciency” is used widely in the paints and
equations 1 and 2).
coatings market. The aim is to oer customers the products they need to produce resource-eɝcient paints and coatings. In this market, “resource eɝciency” characterizes the bundling of the environmental and economic pillars of sustainability [1]. More than any other sector, the corrosion protection market illustrates the impact the use of perfectly tailored pigments and binder systems can have on the function of the coating as a whole and furthermore on the protection/durability of valuable objects.
Causes and mechanisms of corrosion The metallic state is deȴned as a property of solid materials in which the atoms are localized, closely packed, on the lattice sites of a crystal structure while the bonding electrons are free and distributed over the entire crystal [2]. Because of the free availability of electrons, even on the external surfaces of the crystal, all metals are fundamentally subject to corrosion processes. The driving force for corrosion is determined by how easily the electrons are liberated and how easily the metal is oxidized. This depends on the type of metal and is characterized by its electrochemical potential. The chemical reactions that occur during the atmospheric corrosion of iron can be described by the following redox reactions (equations 1-4). Equation 1: Anodic partial reaction
Fe
E0 = - 0.44 V
Fe2++ 2 e-
Equation 2: Cathodic partial reaction
H2O + 1/2 O2 + 2 e-
2 OH
-
E0 = 0.87 V
Equation 3: Sum of the reactions
Fe + H2O + 1/2 O2
Fe(OH)2
Equation 4: Subsequent oxidation with formation of rust
2 Fe(OH)2 + 1/2 O2
56
2 FeO(OH) + H2O
N.32 - 2019 DECEMBER - ipcm® Protective Coatings
© Sean Pavone
INNOVATIONS: PRESENT&FUTURE
In addition, an electrolytic connection allowing transport of ions
suɝcient to initiate corrosion [4].
between anode and cathode and an electric connection for the ȵow
In some cases, like aluminium, corrosion results in a passivating layer
of electrons is required. The latter is usually provided by the corroding
of the corresponding oxide. In case of iron however, the oxide does not
piece. A thin liquid ȴlm, a water droplet, or even human sweat may
adhere to the metal surface as its speciȴc volume is much larger. The
serve as an electrolyte. Dissolved ions such as chlorides and sulfates
rust platelets that form ȵake o constantly, so air, oxygen, and water
accelerate the corrosion process [3]. Fe2+ ions are further oxidized to
will continue to reach the metal surface, until the metal has rusted
the more stable Fe3+ ions and form insoluble Fe(III)-oxide hydroxide,
through.
better known as rust, on the surface.
Corrosion proceeds more slowly in the absence of:
In this case, the anode and cathode are of the same metal, but when
• water
the oxygen concentration diers, a potential dierence is established
• oxygen
[3]. Usually the oxygen-deprived location becomes anodic. Another
• ions.
reason for a potential dierence on one and the same metal is the
This is usually achieved by the application of an organic coating [5]
inhomogeneity of its surface. Edges, steps, kink sites, or voids in the
[6]. However, coatings inevitably have weak points, allowing water,
crystal lattice and contaminants all lead to local potential dierences,
oxygen, or ions to diuse to the metal surface. Therefore, protective coatings usually consist of at least three dierent layers, each with a speciȴc function: a zinc-rich primer, a thick epoxide base-coat, and a
Experts estimate that one-third of all iron and steel products manufactured worldwide per year are used to replace corroded structural components: the economic damage, therefore, is enormous.
polyurethane top coat providing weathering resistance. However, to save costs it is desirable to reduce the number of layers. In addition, increasing environmental awareness and legislative restrictions, which require low-VOC systems, are also a factor. In this work we present a two-layer system that is exceptionally low-VOC and provides full protection against corrosion.
Primer based on a waterborne silane Top coat based on a silicone hybrid resin, a 100% liquid resin The novel waterborne silane system was specially developed for use in two-pack zinc dust paints, which are the coating of choice for long-term corrosion protection. Zinc is usually added as the second component to the aqueous binder. Upon addition, formulations based on the waterborne silane binder cure at ambient temperatures. Such formulations can be applied with a dierent ȴlm thickness on the substrate. The curing time depends on the formulation (type and amount of ȴllers and additives used) and the applied wet ȴlm thickness. As water has to evaporate, the curing time of zinc dust paints containing the water-based silane binder is impacted by the wet ȴlm thickness. Additional factors impacting the curing time are temperature and humidity. The waterborne silane binder is exceptionally safe for the environment yet easy to process and was designed for a better compatibility with additives and ȴllers. The system contains special organofunctional groups which can interact with the ȴller and stabilize the formulation. The advantages of the waterborne silane binder can be summarized as follows: • almost zero-VOC • low-temperature curing • low or higher ȴlm thicknesses are possible • improved heat resistance compared to organic binders.
ipcm® Protective Coatings - 2019 DECEMBER - N.32
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SPECIAL ON PROTECTIVE TECHNOLOGIES FOR BRIDGES, HIGHWAYS, INFRASTRUCTURES
Table 1: Guiding formulation based on waterborne silane-based binder.
Reducing VOCs is a main requirement from the coatings industry and in many countries there are legislations restricting the use of VOCs in coatings. Formulations based on the waterborne silane binder can be
FORMULATION COMPONENT
used to formulate nearly VOC-free zinc dust paints (Table 1).
PARTS BY WEIGHT
Dynasylan® SIVO 14
15.0
Silicone hybrid resin for corrosion protection applications Silicone hybrid resins can be used for corrosion protection applications [7]. In these applications, the coating must meet dierent requirements to fulȴll the needed corrosion resistance. It has to protect the
Deionized water
4.0
TEGO® Wet 270
1.0
TEGO® Twin 4100
0.5
AEROSIL® 200
0.6
Zinc oxide (Red Seal, Ever Zinc)
8.0
on a three-layer application system, built to reach the aforementioned
Mica MKT
7.9
based on a zinc-rich primer, an epoxy intermediate layer, and a PU top
Zinc dust powder (4P16, Ever Zinc)
63.0
Silicone hybrid resins can be used as solvent-free, ultra-high solids
underlying layer by adhering well, while simultaneously preventing harmful substances from migrating to the substrate. It must also be weather resistant. This means not only resistant to rain, snow, and ice but also to the high-energy UV component of sunlight. However, active protection of the steel, with for example a zinc primer, is additionally gained by this second layer, working as a barrier [8]. Conventional coating systems for heavy corrosion protection are based requirements, speciȴed in ISO 12944 (C5, high). The market standard is coat [9]. binders for resource-conserving in many dierent industrial top coat
Total
100.0
COATING PROPERTIES theoretical solids content density coating
~ 88% 2,8 g/cm³
cup eɞux time (DIN 4)
20-30 s
VOC (calculated)
~ 1 g/l
PVC
~81%
DRYING CONDITIONS recommended drying temperature
20-30°C
recommended rel. Humidity
40-80%
drying time – touch dry – 60 wm
10 min
drying time – overcoatable – 60 wm
1 hour © Evonik
Figure 1 - Advantages of silicone hybrid resins.
58
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INNOVATIONS: PRESENT&FUTURE
applications. This technology allows formulation of coating systems with
Table 2: Guiding formulation based on the silicone hybrid resin.
signiȴcantly less than 250 g/L VOC (sometimes even less than 100 g/L) and moreover permits isocyanate-free crosslinking [9].
FORMULATION
The silicone hybrid resin technology combines the positive eects of an aliphatic epoxy resin, like corrosion protection and chemical resistance, with the UV resistance and low yellowing characteristics of an alkoxy
COMPONENT
silicone resin. Together with an amino alkoxy silane hardener, the abilities of the intermediate epoxy layer and the PU top coat can be combined (Fig. 1) [8]. This allows to reduce three to two coating layers, using a combination of water-borne zinc dust primer based on special low-VOC silane binder and a top coat based on a silicone hybrid resin. This two-layer system spares costs and time in many ways: • material cost • labour cost • production time. Thus, new two-layer corrosion protection systems with lower total ȴlm thicknesses and better corrosion protection abilities can be achieved.
PARTS BY WEIGHT
SILIKOPON® EF
55.0
TEGO® Foamex 840
0.7
TEGO® Wet 260
0.6
AEROSIL® R 972
1.0
BENTONE® SD-2
0.5
FINNTALC® M40
8,0
Blanc Fixe ZB
20.0
Black FW 200
1.5
butyl acetate
10.7
butyl glycol acetate
2.0
By reducing the ȴlm thickness, fewer coating materials are needed [8]. Labour costs are reduced signiȴcantly by skipping the second primer coating layer. Moreover, the working time is considerably reduced due to lowering the total drying time for the coating [10], which leads to a faster throughput in the production.
Eco-friendliness (VOC-regulations) Zinc dust paints that are formulated with this innovative binder and ultra-high solid top coat based on the silicone hybrid resin enable the formulator to develop low-VOC coatings systems without compromising properties (versus traditional systems with a higher VOC content) [10]. The VOC emission can be reduced from 120 g/m² to 20 g/m² compared to a common solventborne coating system.
Total
This reduction not only protects the substrate, it also protects the
COATING PROPERTIES
environment. The eco-friendliness is obvious, because of the reduced coating thickness and hence less material using fewer solvents. The silicone hybrid resin based top coat is produced according to the
100.0
theoretical solids content
~ 87%
guiding formulation shown in table 2. The recommended additive and ȴller package, used in the guiding
density coating
1.27 g/cm³
formulation, ensures a good performance in the corrosion tests. cup eɞux time (DIN 6)
15-18 s
VOC (calculated)
~ 170 g/l
Test results The corrosion protection performance was investigated with coatings on blasted steel (surface preparation degree Sa 2.5), according to DIN EN ISO 12944-6 (C5 high, test program 1). A standard three-layer
MIXING RATIO
coating, a commercial 2-pack zinc dust epoxy-primer, a 2-pack epoxy-intermediate layer, and a 2-pack polyurethane top coat (in total: 280wm dry ȴlm thickness) were compared to the two-layer combination of the waterborne silane-primer with the 2-pack silicone hybrid top coat (in total: 185wm dry ȴlm thickness).
hardener
Dynasylan® AMEO coating: hardener
=
100 : 12.8
The results after 1440 hours of neutral salt spray test, according to ISO
ipcm® Protective Coatings - 2019 DECEMBER - N.32
59
SPECIAL ON PROTECTIVE TECHNOLOGIES FOR BRIDGES, HIGHWAYS, INFRASTRUCTURES
© Evonik
© Evonik
Figure 2 - Three-layer standard coating system: 2-pack zinc dust epoxy-primer, DFT: 80wm + 2-pack epoxy-intermediate layer, DFT: 120wm + 2-pack polyurethane top coat, DFT: 80wm.
Figure 3 - Two-layer combination of Zinc dust primer based on waterborne silane, DFT: 60wm + 2-pack silicone hybrid top coat, DFT: 125wm.
9227 have shown in ȴgures 2 and 3.
Summary
In the humidity chamber test, carried out according to ISO 6270-1,
The high crosslinking of coatings based on a silicone hybrid resin
no dierence could be detected. Both coating systems showed no
qualiȴes this binder-technology for highly durable coatings -
blistering after 720 hours exposure. However the adhesion on the
extraordinary gloss, colour retention and weather resistance. Compared
two-layer system was better (GT 0-1 versus GT 2).
with a conventional three-layer system, this two-layer system has better
Another advantage, which is achieved by using top coats based
corrosion protection, even though the dry ȴlm thickness is 95 wm less.
on silicone hybrids, is the higher chemical resistance, because of
In combination with the waterborne zinc dust primer, formulated with
their higher crosslinking density. The coating was exposed at room
the innovative silane-based product, we can achieve an eco-friendly
temperature to 10% solutions of sodium hydroxide and of sulfuric
coatings system, which oers a brilliant solution for the reduction of
acid; no damage was evident on the paint surface. Surfaces based
solvents and material and thus the reduction of costs and additionally
on silicone hybrids also show a good performance in terms of
provides a long-lasting protection against the formation of
easy-to-clean-properties and good abrasion resistance.
micro-channels. ‹
REFERENCES [1] Evonik Industries AG, The Big TEGO, 2013, pp 14-17. [2] Farbe und Lack, Vincentz Network, Issue 10/2012. [3] Guido Kickelbick, Chemie für Ingenieure, 2008, Pearson Studium, an Imprint of Pearson Education (München • Boston • San Francisco • Harlow, England, Don Mills, Ontario • Sydney • Mexico City Madrid • Amsterdam), pp 248 [4] McCaerty, E., Introduction to Corrosion Science, Online-Auȵ., Springer Science + Business Media, LLC, New York, NY 2010, pp 17. [5] Barrow, G.M., Physikalische Chemie, Bd3, 3. Auȵ., Bohmann-Vieweg, Wien 1977, pp 203. [6] Korrosionsschutz von Stahlbauten durch Beschichtungen, Bundesverband Korrosionsschutz e.V., Köln, aktualisierte Ausgabe 2010. [7] www.coating-additives.com, Technical Data Sheet „SILIKOPON® EF”. [8] B. Bröskamp, F. Böss, S. Herrwerth, Ch. Cova-Hög, Ressource Eɝcient Corrosion Protection, ECJ 03/2015 [9] D. Hinzmann, T. Klotzbach, S. Herrwerth, Silcone-epoxy hybrid binders – A Strong Network Against Rust, PAINTINDIA, Vol. 62, No. 11; pp 83-91. [10] M. Hallack, Flyer, Perfect Team for Eco-friendly Corrosion Protection Systems, ECS, 03/2019.
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N.32 - 2019 DECEMBER - ipcm® Protective Coatings
&
W I S H YO U
M E R RY C H R I ST M A S &
2019
HAPPY NE W YEAR
INNOVATIONS: PRESENT&FUTURE
Cracking the Code of Biomass Corrosion with HVTS Marina Silva IGS Integrated Global Services, Inc., Richmond – United States
marina.silva@integratedglobal.com
B
iomass energy is a hot topic in our current climate. While some operators build new biomass-ȴred boilers, others retroȴt old
coal-ȴred boilers to burn biomass. Alcali- and sulȴde-induced corrosion,
however, has become a problem for many boilers. Integrated Global Services (IGS) have developed and ȴeld-tested a novel HVTS metal alloy cladding to cope with corrosion in biomass boilers. Among the adopters of this groundbreaking technology is E.ON in Sweden (Fig. 1), who are now beneȴtting from lower operational expenses. IGS’s European operational team performed a High Velocity Thermal Spray (HVTS) application at E.ON Värme Sverige AB Åbyverket, Örebro, Sweden, on a steam boiler in 2017. ÅP5 is a 170 MW biomass-ȴred CFB boiler built in 1988 by Götaverken-Generator (currently Valmet Technologies Inc.) The steam conditions are 150 bar/540°C. Åbyverket wanted to upgrade the previously installed erosion protection in preparation to the fuel change during the boiler revamp. 20 m height of waterwalls were being changed on all 4 walls.
© IGS
Figure 1 - E.ON Värme Sverige AB Åbyverket, Örebro, Sweden.
Current Fuel mix: Stemwood
10%
Peat
20%
Creosote
30%
Saw dust
20%
coatings, Cyril Narjoz, said: “Some boiler operators believe that weld
Branches, peaks
5%
Dry wood chips
15%
overlay is the only solution to protect boiler walls from biomass-induced
Mix B5
Cl 0,3g/kg
Dust chem
SO3 7,5-41,6%
Flying ash
Cl 0,3%
S 1,3g/kg
Cl 0-5%
S 1,6%
Si 19%
its performance in several independent tests and practical applications.
K2O 11-21% Ca 12,5%
corrosion safely. It was true many years ago, but now HVTS has proven
pH 12,5
With its on-site application being much faster and easier than weld overlay, HVTS has become a favourable alternative for corrosion protection”.
Biomass fuel sources
HVTS application for E.ON
Biomass fuel can be derived from various sources, including virgin
For E.ON Värme Sverige AB, IGS applied 993,5 m2 (20 m band) of HVTS
wood, plants or animal residues, as well as recycled materials, such as
during a 3-week period, working 24/7 with eight spray units. Director
demolition wood. Depending on the type of biomass, the combustion
of IGS European Operations, Petr Sovadina, commented: “Our team is
can generate more or less corrosion and erosion. The type of boiler is
well-trained and experienced, however, this was our ȴrst large project
also an important factor: ȵuidized bed boilers will optimize combustion
in Scandinavia. We found E.ON engineers to be extremely sharp
but will also generate erosion. Various factors inȵuence the choice of
and skilled, this helped us avoid many obstacles during the project
erosion/corrosion protection.
execution. We understand that operators need to squeeze critical path of boiler operations, and that is the reason why we mobilized an
Innovation in corrosion protection
8-gun team to spray 995 square meters of waterwalls in just 21 days.
IGS Subject-Matter Expert on Waste to Energy and Biomass Boiler
We are proud of our quality and provide a warranty for our work.” A
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N.32 - 2019 DECEMBER - ipcm® Protective Coatings
INNOVATIONS: PRESENT&FUTURE
© IGS
boiler engineer with 20 years of experience, Petr spent the last 6 years spraying metal alloy cladding to protect boiler surfaces.
Annual inspection In August 2018, IGS conducted its ȴrst annual inspection of the cladding, and the result was as expected: no deviation on the HVTS cladding thickness (Figs. 2a-2b). A thickness mapping was performed and shared with the customer. E.ON Site Manager has commented: “Our work is extremely important, that is why we choose the best service for our boilers. We closely monitor jobs performed in our boilers, and I shall admit that IGS has an experienced and quality-oriented team that listens to the customer needs and deliver on their promises.” Inspection the following year was conducted and the report stated: “No black areas were detected (bleed through), the cladding turned out to be completely intact and without material loss. Measurements taken showed results similar to those from the year of application.” (Figs. 3a-3b)
About Integrated Global Services Integrated Global Services (IGS) is an international company with a 38-year history providing on-site corrosion protection for power boilers, oil and gas pressurized vessels and heat recovery boilers. IGS has protected more than 2,500 industrial boilers worldwide, including 500+
Figs. 2a and 2b - 2018 inspection: front wall (above) and waterwall near refractory (below).
CFB and BFB boilers. IGS engineering sta utilizes own lab to develop © IGS
and test proprietary metal alloy cladding to cope with corrosion and erosion problems of mission critical equipment. IGS Chief Technology Oɝcer, Iain Hall, commented: “Developed and tested in 2016, our bespoke metal alloy cladding for boiler waterwalls has shown unprecedented corrosion resistance at high temperatures found in Biomass boilers combined with its ease of on-site application.”
Global Service – Local Support Having operational centers in strategic locations in North America, Europe, Asia and Africa, IGS delivers its services worldwide, but each market is special. Sören Stutin, General Manager IGS Scandinavia, commented: “Scandinavia is a highly educated market. Our boiler engineers have a deep understanding of metal wastage problems in boilers and multi-year experience of using thermal spray solutions. But what is the most important – Scandinavian engineers are open to innovation and absorb the best available technology to improve their operations. Swedish engineers are well-educated, curious and savvy. That makes our boiler industry so advanced.” As the European energy market is experimenting with dierent biomass fuels, boiler engineers will face more arduous corrosion situations. IGS can provide an eective barrier on the existing pressure parts, which will prevent further need of panel replacement. ‹
Figs. 3a and 3b - 2019 inspection: thickness readings (above) and waterwall near refractory (below).
ipcm® Protective Coatings - 2019 DECEMBER - N.32
63
© Adobe Stock
INSPECTION LOGBOOK
Coating Inspections: Capability Levels of Coating Inspection Personnel Massimo Cornago NACE International Certified Coating Inspector, NACE CIP PEER Reviewer cornago@ipcm.it
C
oating Inspectors can be categorized by experience and education into dierent capability levels. A typical categorisation of the
inspectors’ groups into three dierent levels: Level I, Level II and Level III (ASTMD4537, ANSI/ASMEN45,2,6, FROSIO, NACE International). Candidates for certiȴcation as “coatings inspectors” should have suɝcient education, experience, and training to ensure an understanding of the principles and the procedures in those areas of inspections for which they are being considered for certiȴcations. A typical summary of minimum requirements for the three levels follows.
Level I inspector 1. Education, training and experience qualiȴcations Level I coatings inspectors, as a minimum level of education, should meet one or more of the following requirements: • High school graduation plus six months of related experience in equivalent inspection activities. • Completion of college level work leading to an associate’s degree or higher, plus three months of related experience in equivalent inspection activities. 2. Responsibilities and capabilities
• Completion of college level work leading to an associate’s degree or
• Implementing and recording all inspections required by the applicable
higher, plus one year of related experience in equivalent inspection
procedures.
activities.
• Verify instrument calibration.
• Four years collage degree plus six months of related experience in
• Performing hold point inspections and releasing hold point in
equivalent inspection activities.
accordance with the applicable procedures. 2. Responsibilities and capabilities
Level II Inspector
• Performing all of the duties and responsibilities of a Level I coating
1. Education, training and experience qualiȴcations
inspector.
Level II coatings inspectors, as a minimum level of education, should
• Planning and supervising inspections, initialling and reviewing
meet one or more of the following requirements:
inspection procedures, and evaluating the adequacy of activities.
• High school graduation plus one year of satisfactory performance as a
• Revising, organizing and approving results of inspections.
Level I coating inspector in the corresponding inspection activity.
• Monitoring the performance of and supervising the work of Level I
64
N.32 - 2019 DECEMBER - ipcm® Protective Coatings
INSPECTION LOGBOOK
• High school graduation, plus ten years of related experience in equivalent inspection activities, or high school graduation, plus eight years’ experience in equivalent inspection activities, with at least two years as a Level II coating inspector, and with at least two years associated with industrial facilities, using high technology coatings, or suɝcient training to be knowledgeable of the quality assurance requirements for industrial work. • Completion of college level work leading to an associate’s degree and seven years of related experience in equivalent inspection activities with at least two years of this experience, associated with industrial facilities, using high technology coating or suɝcient training to be knowledgeable of the quality assurance requirements for industrial work. • Four years college degree plus ȴve years of related experience in equivalent inspection activities, with at least two years of this experience associated with industrial facilities, using high technology coating, or suɝcient training to be knowledgeable of the quality assurance requirements for industrial work. 2. Responsibilities and capabilities • Carrying out all of the duties and responsibilities of a Level II coating inspector. • Certifying Level I, Level II and other Level III coatings inspectors. • Evaluating the adequacy of programs used to train coating inspectors. • Authorising Level II coating inspectors to carry out training and examination duties. • Approving all safety-related inspection procedures. It’s useful to remember that NACE International, in his Coating Inspector Program and Peer Review, requires to any Candidate to the course to sign the “Coating Inspector’s Attestation”, becoming a part of their permanent record. The Coating Inspector’s Attestation is a particular “indication”of how the inspector must continuously strive to maintain high personal integrity and a strong work ethic. coatings inspectors.
In conclusion the “Certiȴed Coating Inspectors” must have the physical
• Training and verifying the qualiȴcations of a Level I coatings inspectors
capabilities and training to meet all their work requirements. It is also
for certiȴcation.
essential that they have good verbal and written communication skills,
• Initiating changes to quality procedures.
strong character and good judgement.
• Implementing the quality assurance program if assigned that authority
Based on their experience and education, the “Coating Inspectors” can
by company policy or the quality assurance program.
be certiȴed at dierent levels, enable to assume greater responsibility and authority, including the supervision and training of lower level
Level III Inspector
inspectors. ‹
1. Education, training and experience qualiȴcations Level III coatings inspectors, as a minimum level of education, should meet one or more of the following requirements: • High school graduation plus ȴve years of satisfactory performance as a Level II coating inspector in the corresponding inspection activity.
ipcm® Protective Coatings - 2019 DECEMBER - N.32
65
ZOOM ON EVENTS
The Global Forum for Steel Pipeline Coatings and Protection Polymeric coatings and protection for pipelines create a complex
their challenges with coating applications on steel pipes oering an
challenge for the steel pipe industry. With the oil price recovering
opportunity for the supply chain to oer and ȴnd solutions.
much of the ground lost towards the end of 2018, new exploration and production of O&G, the increase in popularity of shale and LNG and
New for 2020
the requirement for improved pipe infrastructure, the industry will
AMI and the Young Pipeline Professionals Europe (YPPE) have joined
experience a future up-turn in production and projects.
forces to help promote young professionals within the pipeline and coatings industry. With the need for new freshly-graduated and trained
The Pipeline Coating conference is focused on polymeric coatings
professionals in the pipeline industry, AMI and the YPPE have started on
and their protection for oshore and onshore steel pipelines for the
this partnership to help promote the fresh talent entering the industry.
energy industries looking at key themes (pipe storage, insulation for
With members of the YPPE sharing their projects and research in a
harsh environments, coating failure and new generation coatings &
poster-display in the busy exhibition room. At the end of the ȴrst day
technologies). Taking place from a central-European location (Vienna,
of technical presentations, a member of the YPPE will provide a brief
Austria) the event oers a location for companies to attend from Europe,
introduction to the association, they will then, along with a sponsor of
Asia-Paciȴc, NAFTA, MEA, CIS and South & Central American regions.
the association, present an award recognising a piece of research that
The Pipeline Coating programme has been selected by an Advisory
has made a dierence to the industry.
Board, which includes expertise from AMI and external representatives
AMI has organised events in the oil & gas industry for the past 12 years.
who are all leaders in their ȴeld and bring their experience and
The event attracts operators & asset owners (Saudi Aramco, ADNOC,
knowledge, including Houssam Al Din Sabry from ADNOC,
Total, TC Energy, ENI, Equinor and Qatar Petroleum have already
Denis Melot from TOTAL, Michele L. Ostraat from ARAMCO SERVICES,
conȴrmed their attendance), contractors and lay engineers, raw material
Somaieh Salehpour from SHAWCOR, Jerey D. Rogozinski from
suppliers, pipe coaters, speciȴers, machinery suppliers, researchers and
SHERWIN-WILLIAMS, Thomas Stark from BOREALIS, Mike Surkein from
testing and certiȴcation organisations.
SURKEIN CORROSION, Samuel J. Thomas INDEPENDENT CONSULTANT
Pipeline Coating 2020 has been supported by Shawcor, returning as the
(currently at Liberty Coatings), Philip D. Tooth from TOOTH PIPELINE
headline sponsor, Sherwin-Williams, 3M, Borealis, Jotun, Tenaris,
SERVICES as well as Rebecca Utteridge, AMI.
Akzo Nobel and Charter Coating 2000. The event is supported by YPPE
On the 11-13 February 2020, the event will provide delegates the
and has media partnership with Pipe & Proȴle Extrusion, World Pipelines,
chance to participate in two days of technical conference presentations.
PCE and IPCM_Protective Coatings.
Speakers include Borouge, Jabitherm, Shawcor, Tenaris, AkzoNobel,
Pipeline Coating 2020 takes place 11-13 February, at the Austria Trend
3M, TC Energy and Charter Coatings, Sherwin-Williams, Eckart Suisse,
Savoyen Hotel, Vienna, Austria.
Seal for Life Industries, Pipeline Technique and the University of Zagreb, Faculty of Chemical Engineering and Technology.
For further information:
Concluding the conference, Total, ADNOC and Saudi Aramco will share
www.ami.international/events/event?Code=C1039
© iStock
Pipeline Coating 2020 takes place 11-13 February, at the Austria Trend Savoyen Hotel, Vienna, Austria.
66
N.32 - 2019 DECEMBER - ipcm® Protective Coatings
ZOOM ON EVENTS
Conference Programme for StocExpo 2020 Unveiled © Easyfairs
transported using existing liquid fuel infrastructure and will share with delegates the build-up of the company’s ȴrst industrial-scale project. Clearly sustainability has ramiȴcations for how terminals are operated. Considering this, Rian Vermeulen, Sr Advisor BRO, and Dennis Risseeuw, Business Consultant Engie will outline a unique approach to terminal sustainability – including measures to become more energy eɝcient, produce more renewable energy and protect local ecology. Building on this, Khalid Saleh, Energy Coordinator, Vopak will share the company’s sustainable energy initiatives including CO2 emission reductions. In a talk focused on the long-term impact of energy transition Giacomo Boati, Director, Oil Markets, Midstream & Downstream Consulting, IHS Markit will review the expected trends in decarbonisation of the transportation sector and the impact of this. A future thinking panel will then pull all of this together to debate what the storage terminal will look like in 50 years’ time, before the ȴrst day of
The StocExpo conference, at the Ahoy in Rotterdam in March, 2020 will feature 20 world-class speakers.
the conference ends with a regulatory update provided by Ravi Bhatiani, Executive Director, FETSA. The second day of the StocExpo conference starts with sessions on the implications of emerging markets and the US trade wars and taris.
The conference programme for StocExpo, the world’s largest and longest
Andrew Inglis, Vice President of Energy and Fuels in EMEA, Nexant will
running international bulk liquid storage event, which returns to the
consider the shift in global demand from mature markets to emerging
Rotterdam Ahoy from 10 – 12 March 2020, has been unveiled.
markets. While Samuel Ciszuk, Founding Partner, ELS Analysis will examine how US trade wars / taris are impacting international tradeȵows.
The two-day conference will feature a powerful mix of talks focused
The conference then changes focus, with a series of expert talks on the
on critical global issues such as sustainability, the impact of energy
very latest developments, technologies and thinking designed to improve
alternatives, emerging markets, latest technologies and trends, all
day-to-day terminal operations. These include improving cyber security,
delivered by 20 world-class speakers.
with Martin van den Bosch, Digital Forensic Investigator, Netherlands
Artur Runge-Metzger, Director, DG CLIMA, European Commission will
Seaport Police who will outline how to protect against storage spooȴng.
open the conference with an assessment of the future of sustainable
Attendees of the StocExpo 2020 conference will also have plenty of
transport and the EU’s energy policy. He will be followed by speakers
networking opportunities plus an exhibition where over 200 suppliers
covering the future implications of changes to the energy mix including
from across the globe will be showing their latest innovations under one
LNG, a non-hydrocarbon future and the growth in hydrogen.
roof.
In considering the growth of LNG, Wim Groenendijk, Managing Director,
StocExpo takes place from the 10th to the 12th March 2020 at the
Gate Terminal will outline the development of a Northwest European
Rotterdam Ahoy.
multi-modal LNG Hub and the opportunities it presents in the context of decarbonisation and energy transition. Charles Daly, Chairman, Channoil
For further information: www.stocexpo.com
Consulting will then explore how oil terminals need to change if they’re to stay in business in a non-hydrocarbon scenario. The world’s key terminals, storage players, energy companies, investors and analysts are all monitoring closely the development of hydrogen, keen to gauge its future demand and the impact this will have on their businesses. To answer this, Daniel Teichmann, Chairman, Hydrogenious will consider the latest political and industrial developments which are establishing hydrogen as an emission-free fuel. He will show how, thanks to Liquid Organic Hydrogen Carrier (LOHC) technology, hydrogen can be
ipcm® Protective Coatings - 2019 DECEMBER - N.32
67
Protective Coatings ®
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Protective Coatings ®
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THE MAGAZINE ABOUT CORROSION CONTROL AND
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PREVENTION TECHNOLOGIES
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2019 - 8th Year | Quarterly - N.32 December
Prof. Paolo Gronchi Department of Chemistry, Material and Chemical Engineering, Politecnico of Milan – Chemical Engineering Section
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