GALVANIZED STEEL AND SUSTAINABLE CONSTRUCTION SOLUTIONS FOR A CIRCULAR ECONOMY
European General Galvanizers Association (EGGA) is the industry organisation for Europe’s general galvanizing sector. It is a federation of 14 National Associations that represent the industry in Europe. The ‘European Initiative for Galvanizing in Sustainable Construction’ started with multi-stakeholder assessments in the early 2000s that culminated with the publication, in 2008, of ‘Galvanizing in Sustainable Construction: A Specifiers’ Guide’ 1 under the guidance of Professor Tom Woolley – a radical advocate of green building who prompted a fresh and exciting look at hot dip galvanizing and its consistency with sustainable design. This latest publication explains how the galvanizing industry is moving forwards - keeping galvanized steel at the forefront of solutions for tackling climate change and delivering the circular economy that is now firmly established in both policy and practice. Galvanized steel can provide innovative solutions that optimise durability and facilitate circularity of steel structures and components. These solutions can be easily implemented using this well-established and simple method of protecting steel.
Cover: MFO-Park, Zurich: Galvanized steel is used to revitalise an old industrial site
GALVANIZED STEEL AND SUSTAINABLE CONSTRUCTION SOLUTIONS FOR A CIRCULAR ECONOMY
Published by EGGA | March 2021 © Copyright 2021 European General Galvanizers Association www.egga.com 3
Make
Use
Recycle
Remake
Reuse
CONTENTS
Case studies 7 The challenge of sustainable construction 9 Galvanized steel in the circular economy 18 Galvanized steel – circular economy policy into practice
13 The Green House – design for flexibility and reuse 16 Information Point – ready for relocation and repurpose 23 Designed for deconstruction – Fraunhofer IWKS
25 Design for reuse of galvanized steel
31 Grandstand at Gramsbergen – rebirth after 40 years
27 The robustness of galvanized steel for reuse
34 Dursley Treehouse
37 Regalvanizing of galvanized steel infrastructure
40 Leeuwarden Energy Knowledge Centre
43 Recycling of zinc on galvanized steel
45 House D6 – sustainable reversible housing
47 Reducing carbon through avoidance of maintenance
46 Thinking ahead – repurposing of galvanized steel
52 Life cycle sustainability of galvanized steel structures
54 Lydlinch Bridge – built 1942 and in great condition
57 How galvanizing protects steel
56 Railway building in Bavaria – 120 years life and still going strong
63 The galvanizing industry
61 Garsington Opera – demountable pavilion
69 Environmental product declarations
74 Please be seated
72 Galvanizing for healthy buildings 75 References 77 Acknowledgements and credits 78 Circular economy terms 79 Further information on galvanized steel
Throughout this document the term ‘galvanized steel’ refers to steel articles that have been immersed in molten zinc after the articles have been fabricated or manufactured. This is the process of batch (or ‘general’) galvanizing that is usually carried out according to EN ISO 1461 to provide a zinc coating that is thick, tough and gives complete coverage of the steel article. This combination cannot be achieved with other types of zinc coated steel.
5
THE CHALLENGE OF SUSTAINABLE CONSTRUCTION oncerns about the C effects of climate change are both serious and urgent
To avoid the adverse effects of climate change,
The galvanizing industry has welcomed this
The International Panel on Climate Change
increasing focus on the creation of a circular
(IPCC) has recommended that global emissions
economy – embracing design for durability,
of greenhouse gases, of which CO2 is the most
deconstruction, disassembly and flexibility as
important, should be cut, to achieve climate
well as on reuse, recovery or remanufacturing
neutrality by 2050. The objective is to limit
of materials. Galvanized steel structures and
global warming to 1.5°C above pre-industrial
components are ideal circular materials for
levels .
low carbon buildings.
The concerns about effects of climate change
Steel is essential to the technologies and
are both serious and urgent. With a growing
solutions that meet society’s everyday needs
world population and a consequent increasing
and will continue to do so in the future. Whether
use of engineered materials, the need for a
it is for transport systems, infrastructure,
new approach to maximise the value of raw
housing, manufacturing, agriculture or energy,
materials by keeping buildings, infrastructure,
steel is widely recognised as the ‘permanent
resources and materials in use for as long as
material in the circular economy’.
2
possible is clear. In the search for optimal sustainability in the The first European Climate law 3, introduced
use of materials, the combination of hot dip
by the European Commission in 2020,
galvanizing and steel creates an almost unique
proposes a legally obligatory target of net-zero
partnership in delivering sustainable design
greenhouse gas emissions by 2050 as part of
choices.
the EU Green Deal4. These ambitious objectives are supported by initiatives to transition Left The Green House (see p12+13)
industry to a sustainable model based on the principles of a circular economy. 7
Make Galvanizing is an efficient dip process – giving the highest level of protection for steel. Galvanizing of steel products maximises their durability, reuse and recycling.
Recycle
Use
Steel and zinc are recycled together – without loss of properties – if the long life of galvanized steel eventually ends.
Galvanized steel is completely covered with a durable coating that can last the lifetime of the component – avoiding resource use for replacement or maintenance.
Remake
Reuse
Galvanized steel products can be regalvanized and put back into service – avoiding production of new steel. Repurposing of galvanized steel products is often possible without regalvanizing.
Galvanized steel is robust and easily dismantled for reuse in multiple life cycles. The coating stays with the steel component in its next life cycle.
8 GALVANIZED STEEL AND SUSTAINABLE CONSTRUCTION
GALVANIZED STEEL IN THE CIRCULAR ECONOMY Construction in the Circular Economy
A circular economy also ensures that value is
The circular economy is a move from linear
the end of its useful life while at the same time
business models, in which products are
reducing or eliminating waste. This idea is
manufactured from raw materials and then
fundamental to the triple-bottom line concept
discarded at the end of their useful lives, to
of sustainability, which focuses on the interplay
circular business models where intelligent
between environmental, social and economic
design leads to products or their parts being
factors. Without a life cycle approach, it is
repaired, reused, returned and recycled.
impossible to have a genuine circular economy.
A circular economy aims to rebuild capital,
The construction sector is a priority for
whether it is financial, manufacturing, human,
a circular economy because, based on a
social or natural. This approach enhances the
building's full life cycle5 it is responsible for:
maintained within a product when it reaches
flow of goods and services. The concept of the circular economy drives optimal resource
– 50% of extracted materials
efficiency. lt makes sure that resources are
– 50% of total energy consumption
efficiently allocated to products and services in
– 33% of water use
such a way as to maximize the economic well-
– 35% of waste generation
being of everyone. In addition, products need to be designed to be durable, easy to repair
Circular construction means thinking, from the
and, ultimately, to be recycled. The cost of
outset, about how to design a building to be
reusing, repairing or remanufacturing products
able to dismantle easily its components at the
has to be competitive to encourage these
end of the building’s lifetime in order to reuse
practices. Simply replacing a product with
them.
a new one should no longer be the norm.
9
Features of galvanized steel
Avoid
Facilitate
Maintenance
Reuse
Durability, Robustness and Adaptability of Galvanized Steel
Avoid
Healthy
Replacement
Buildings
10 GALVANIZED STEEL AND SUSTAINABLE CONSTRUCTION
To achieve this, constructors are changing their way of thinking to:
– A galvanized coating is inherently climate resilient as its protective ability is largely unaffected by changes in temperature and
– Design flexible and adaptable buildings, that provide basic functions for a long period, but at the same time can be adapted. – Design in a ‘re-functionable’ way. At design
other climatic factors. – Galvanized coatings are bonded to the steel, which allows the steel product to be reused along with the original coating without need
stage take into account future new functions
for recoating (just think of those scaffolding
and new users for a building.
poles that are repeatedly assembled and
– Make sure that components are re-usable and design the building accordingly. – Use resources with a positive residual value.
Why Galvanized Steel? Recognition that the concept of a circular
disassembled around our buildings). – Galvanized steel components that have reached the end of their design life, or are uninstalled for any other reason, can be regalvanized and returned to the original use. – If the reuse cycles come to an end, both
economy is fundamental to optimising
steel and zinc are recycled together in the
sustainability of materials has again brought
well-established steel recycling processes
the simplicity, robustness, durability and
– with the zinc being returned, without loss
inherent recyclability of metal structures and
of properties, to zinc production plants and
components to the forefront of sustainable
eventually back into the galvanizing process.
design. Hot dip galvanized steel perfectly illustrates this:
If a material system was specially designed for the circular economy, hot dip galvanizing would
– Hot dip galvanizing of steel products after
be an excellent example. But, it is here today
fabrication delivers the highest levels of
and has been following these principles for
corrosion protection – the steel structure or
decades.
component will often achieve its design life with no maintenance. – The galvanized coating can follow the steel structure through multiple cycles of reuse. Above The Silo, Copenhagen
11
THE GREEN HOUSE – DESIGN FOR FLEXIBILITY AND REUSE
Reuse
The Green House houses a restaurant with its
The hot dip galvanized steel perfectly
own urban farm and a conference centre. True
underscores the bold character of The Green
to the principles of the circular economy, the
House and the urban-farming greenhouse.
entire building can be disassembled. Owing to
The architects also recognised that hot dip
their high degree of precision, steel components
galvanizing lends itself perfectly to disassembly
are easy to take apart and put together again.
and reassembly - as the coating will not be
A special feature of the steel frame of The Green
damaged in that procedure.
House is its square grid, with which multiple building configurations are possible with one-and-the-same construction kit. In fifteen years, it is anticipated to be taken apart and rebuilt at another site. Reuse also played an important part in the choice of materials for the project.
The Green House could be completely taken apart and rebuilt at another site
The pavilion was designed as a generic construction kit with a steel frame comprised of hot dip galvanized steel sections that can easily be disassembled for reuse. Galvanizing was also used for trellis trusses for the façade, the roof (including roof construction for a small greenhouse), balustrades and the staircase within the pavilion.
13
Hierarchical models of the circular economy illustrate the importance of galvanized steel Priorities in the Circular Economy
Actions in the Circular Economy
Galvanized Steel in the Circular Economy The highest level of durability and
High Refuse
robustness – giving ‘once-only’ solutions that last the lifetime of a building
Reduce
Make
Resource use for maintenance is avoided
Use Robust and easily dismantled for Reuse
reuse in multiple life cycles of a building or structure
Reuse Coating stays with the steel and no Repair Refurbish Remanufacture Repurpose
additional coating is needed in any new use Can be re-galvanized and put back into service – avoiding production of
Remake
new steel If the long life of galvanized steel Recycle Low
Recover
eventually ends, steel and zinc are recycled together – without loss of properties – to produce new galvanized steel
14 GALVANIZED STEEL AND SUSTAINABLE CONSTRUCTION
Recycle
Delivering the Circular Economy
If designers want to integrate reusable steel elements in the
The hierarchy models of a circular economy illustrate very well the
structural part of a building, galvanizing is the ideal coating
important role of galvanizing to enhance the already favourable
system. Galvanized steel will not suffer from demounting and
position of steel as a circular material because a galvanized
remounting activities as opposed to painted steel that will need
coating becomes an integral part of the steel structure that will
to be repainted or at least repaired. Moreover, galvanizing offers
resist impact and abrasion during disassembly and reuse of the
longer lifetime expectations to steel than other coating systems,
steel. This feature is of great value to the reuse, remanufacture
which allows frequent reuse of the material.
and repurpose of steel structures and components. In a circular economy, there will be a shift from a productReducing the weight of products and therefore the amount of
based economy towards a service-based economy. Repair/
material used, is key to the circular economy. The steel industry
maintenance will be increasingly important as will efforts to limit
has developed high-strength and advanced high-strength steel
the distance between the repair shop and the user, to minimise
grades for many applications. These grades contribute to the
the environmental impact. This will stimulate local economies and
light-weighting of applications, from wind turbines to construction
increase ease of use for the end user.
panels and automobiles, as less steel is needed to provide the same strength and functionality. By providing maximum levels
Steel products are easily repaired or the entire repaired steel
of corrosion protection, galvanizing allows thinner, lighter steel
product can be re-galvanized.
sections to be used because additional allowances for corrosion losses during service are avoided.
Steel and zinc are 100% recyclable and can be recycled over and over again to create new steel products in a closed material loop.
Steel can be reused or repurposed in many ways, with or
Recycled steel maintains the inherent properties of the original
without remanufacturing. This already occurs with automotive
steel and its magnetic properties ensure easy and affordable
components, buildings, train rails and many other applications.
recovery for recycling from almost any waste stream while the
Reuse of steel is not limited to its original application; repurposing
high value of steel scrap guarantees the economic viability of
dates back to ancient times (turning swords into ploughshares).
recycling. Today, steel is the most recycled material in the world.
Rates of reuse will increase as ecodesign, design for reuse and
Over 650 million tonnes of steel are recycled annually, including
recycling, and resource efficiency become more commonplace.
pre- and post-consumer scrap6.
15
INFORMATION POINT – READY FOR RELOCATION AND REPURPOSE The Les Glòries development on the eastern
After careful research of their intended
flank of Barcelona has been one of the city’s
materials, a structure that uses galvanized
most significant urban upgrades. During the
steel tubes for the external frame combined
regeneration of the area, Barcelona City Hall
with a translucent polycarbonate skin and
wanted an Information Point that would inform
prefabricated timber internal modules was
local residents about the development but
chosen. These modules serve as information
also provide information for tourists.
desks and a bicycle rental point. All this was
Remake
Reuse
delivered within a budget of €170,000. A closed competition was won by the local architects Peris + Toral for a temporary
After serving its function gracefully since 2015,
structure that could be moved to another
Peris + Toral have recently been tasked by
location after its planned 4-year role as an
Barcelona City Hall to repurpose the structure
Information Point.
as a youth centre (casal de joves in Catalan) in the city’s St Martí neighbourhood.
16 GALVANIZED STEEL AND SUSTAINABLE CONSTRUCTION
Below The structure is easily demountable and can be relocated and reused with minimal impact on the site
Left Galvanized steel was used to create a temporary structure to protect the building during the surrounding regeneration of the area. Materials were chosen that created transparency to the structure but could also be readily deconstructed for a new life Below left The structure is both an information point and rental location for electric bicycles
Below The structure is now being repurposed by the architects as a youth centre in another part of the city
17
GALVANIZED STEEL – CIRCULAR ECONOMY POLICY INTO PRACTICE The recently-launched European Commission ‘Circular Economy: Principles for Buildings
Scope of the ‘EC Circular Economy Principles for Building Design 2020’
Design’ 7 envisages three key scenarios (or
Specific Objectives
objectives) for achieving reduction of waste, the optimisation of material use and the
Target group
reduction of environmental impacts of designs and material choices throughout
Building users, facility
the life cycle.
managers and owners
The Commission's three objectives are
Design
explained as:
teams
Durability
Contractors
Durability of buildings depends on better
and builders
design, improved performance of construction products and information sharing. Structural
Manufacturers (of
elements should last as long as the building
construction products)
does, whenever possible. If it is not possible because of intrinsic obsolescence
Deconstruction
or anticipated change in requirements,
and demolition teams
they should be reusable, recyclable or dismountable.
Adaptability
Investors, developers and insurance providers
Preventing premature building demolishment
Government/regulators/
by developing a new design culture.
local authorities
18 GALVANIZED STEEL AND SUSTAINABLE CONSTRUCTION
Durability
Adaptability
Reduce Waste
Reduce waste and facilitate high-quality waste management Design products and systems so that they can be easily reused, repaired, recycled or recovered.
The wider use of batch galvanized steel is fully consistent with these new objectives of building design for the circular economy. The high level of durability of galvanized steel is proven. When constructing with galvanized steel, reuse can be an even more prominent solution than is implied by these objectives. Reuse is a valuable approach to both delivering adaptable buildings and to reducing waste. The European Commission has identified ways in which these principles can be implemented by each of the main actors in the construction value chain. In the following table, the main principles of that policy highlighting the importance of the durability of galvanized steel have been extracted.
Right Car park at Moorsport, Leiden
Key principles on durability and other aspects within the ‘EC Circular Economy Principles for Building Design 2020’ Target Group
Drivers for use of galvanized steel
Building users, facilities Minimise the total cost of ownership over time managers and owners
Owners and building users have an interest in overall and longer-term horizons – Reduce the total cost per square metre/comparative average – Use tools to enhance the building’s value Promote durability during the use phase – Provide incentives through performance-based contracts that promote the optimal use of the building
Design teams
It is essential to have knowledge of circular economy principles to design buildings and materials
(engineering and
Architects and designers should be familiar with design requirements and strategies, the concept of life cycle
architecture of
assessment, the potential to increase the content of recycled materials in products, future reuse potential
buildings)
(product, component and building); (future) recyclability and transformation capacity (reuse potential and reversible building design score – Encourage designers to adopt a life cycle approach when designing new buildings – Use existing guides on DfD/A* and feedback from previous project examples Architects and designers need to take into account whole life costs and benefits The whole life cycle must take into account the operational cost of the building as well as the potential changes to the building’s use. They include environmental and social impacts and benefits, transformation capacity, reuse and recyclability potential
Contractors and
Use construction techniques that promote the durability of buildings and the resilience of the materials
builders
– Simulate different scenarios of durability and compare costs – Include the resources needed for resilience to installation error – To enhance the building’s durability, use construction techniques that facilitate maintenance and repairs to different parts of buildings and building products and systems
*
Design for Disassembly and Adaptability
20 GALVANIZED STEEL AND SUSTAINABLE CONSTRUCTION
Target Group
Drivers for use of galvanized steel
Manufacturers (of
Consider the potential durability level for the whole life cycle of the building based on evidence from
construction products)
LCC of the product – Use whole life costing and environmental assessment integrated with supplementary information beyond the building life cycle – Use qualitative and resistant products for their environmental and use attributes Ecodesign principles should be used and durability assessed Product standards, if not yet developed, should include durability and a verification system to confirm such durability Solutions should be developed for greater adaptability For example, in works, prefabrication and modular systems
Investors, developers
Enhancing durability will decrease financial risk
and insurance
The importance of durability of products and materials should be promoted within the overall approach to
providers
buildings and products, and how this can be appropriately accounted for financially Life Cycle Costing should be promoted when preparing investment decisions The increased revenue streams that can be generated through reversible design should be integrated into the whole costing analysis – Capitalise future risks of difficulty to deconstruct buildings and cost of waste management – Consider the residual value of buildings to help with savings in mortgages and money flows – The use of the ISO standard for DfD/A credits within Green Public Procurement and sustainable building rating schemes provide an incentive to consider at this stage
Government/
Reinforce policies that promote reuse and high-quality recycling of buildings/building materials
regulators/local
Integrate life cycle approaches in construction policies
authorities
Provide incentives for the development of design principles for circular and sustainable buildings Reversible products might use more resources at the start (due to more robust design, for example), but make it possible to recover the resources but also reuse the product in multiple life cycles
21
DESIGNED FOR DECONSTRUCTION – FRAUNHOFER IWKS
Recycle
Reuse
The Fraunhofer IWKS (Institute for Materials
are free of harmful substances and can be
Recycling and Resource Strategies) is at the
easily separated and reused or recycled when
forefront of research into the responsible
future deconstruction is necessary. This choice
use of natural resources – based on the
included extensive use of galvanized steel in
principle that resources should be used but
the façades of the building. The galvanized
not consumed. Their focus is on recovery of
coating of these façades will develop a highly
materials and reintroducing those materials
stable surface patina over future decades and
into new product cycles.
create an aesthetically pleasing as well as sustainable solution.
The important work of Fraunhofer IWKS will now be carried out from a new building
“Sustainable building and the most modern,
in Hanau, Germany that has been built in
high-tech research infrastructure, that’s
accordance with the same sustainability
possible. Both outside and inside, sustainability
principles that drive their activities. This office
and energy efficiency in construction were
and technical centre houses 80 employees in
our top priority“, said Andreas Meurer, board
a 2600m building that ensures short distances
member of the Fraunhofer-Gesellschaft, at
for good orientation and spaces for informal
the official opening of the building, adding
communication.
that “The façade is clad with galvanized steel
2
Above Fraunhofer IWKS conducts research into the recovery and reuse of materials within the circular economy Left The galvanized steel façade was chosen to facilitate future deconstruction and reuse as well as for its natural aesthetics
plates, for example. Steel makes an important An important objective for the building was
contribution to zero waste management. The
the target of silver certification according to
steel can be completely recycled. The material
the guidelines for sustainable construction
cycle is thus closed, without any loss of quality.“
for federal buildings in Germany (BNB). Designed by hammeskrause architekten bda, the building is constructed of materials that 23
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