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2 Concrete Bridges
Contents 3 Introduction
4 Function and elegance
5 Built to last
6 Versatility
8 Fast construction
10 Sustainable bridge design
12 High performance concrete
14 Case studies
15 Conclusion
15 References
Bridge design and construction is a challenging and exciting field, calling for creativity and ingenuity to deliver beautiful, robust and durable structures that will stand the test of time, allowing people, vehicles and trains and sometimes even boats to cross streets, roads, railways, rivers, valleys and estuaries.
Introduction
Aesthetics Dynamic, graceful, long-span concrete bridges often become landmarks in their own right.
Durability Concrete bridges have a service life of 120 years or more. They can be designed to withstand extreme temperature changes and corrosive chemicals in a variety of conditions.
Versatility The forms that concrete structures can take are limited only by the imagination.
Buildability Precasting in conjunction with sliding, launching and other fast methods make construction in concrete ever quicker.
Sustainability Socially responsible construction is possible through the use of both local and recycled constituent materials.
Economy Competitive initial construction costs, coupled with reduced inspection and maintenance, means concrete’s cost-efficiency is very attractive in the long-term.
Concrete Bridges 3
More bridges are built using concrete than any other material
worldwide. Indeed, following its introduction as a widespread
construction material, and the pioneering work by the French
bridge engineer Freyssinet during the early years of the last
century, concrete has been an increasingly popular choice for
bridge construction. Today, concrete continues to be used in mass,
reinforced and prestressed applications to deliver a wide range of
different substructure and superstructure bridge forms. The growing
number of concrete bridges in use on every continent demonstrates
continued confidence in the material’s performance and durability.
Concrete bridges worldwide have a clear track record of flexibility
and versatility in terms both of final forms and methods of
construction that is hard to match.
As the material science develops, so does the potential for
concrete bridges. Recent advances in both concrete and bridge
construction technologies afford the bridge owner, designer and
constructor better value, reliability and safety than ever before. New
developments in high strength concrete offer engineers the ability to
span longer distances and to produce ever more economic designs.
Concrete brings many construction advantages to any project. Its
intrinsic durability, versatility, mouldability and economy coupled
with its availability as a locally sourced material (there is generally
a concrete ready-mix concrete plant within six radial miles of every
construction site in the country) means that concrete is the natural
material of choice for bridge structures.
Universally applicable, in-situ concrete is readily obtainable and
easily incorporated into all bridge components from foundation piles
to feature finishes. Additionally, many bridge components can be
precast in factory conditions, ensuring that they are both precision
engineered and quick to erect when delivered to site.
Concrete can easily meet society’s demands for improved
sustainability, with a production process that can use recycled
aggregates and blended cements containing industrial by-products.
Additionally, many owning and maintaining authorities are becoming
increasingly conscious of the significant costs and disruption
caused by routine maintenance over the life-cycle of bridges. The
considerable advances made in concrete technology and structural
detailing provide enhanced durability, attractively reducing
maintenance burdens.
This guide explores the reasons why concrete is the material of
choice for bridge construction. It is aimed at all members of the
bridge design team from clients to bridge designers and constructors.
The information included encapsulates current best practice
guidance on concrete design for bridges, and concrete bridge
construction methods. Bridge case studies also demonstrate some
innovative uses of concrete and explain the benefits brought to
the projects.
Cover images:Main picture: A1 Tyne bridge, Scotland. Courtesy of Scott Wilson.Inset image, top: Kildare bridge, Ireland.Inset image, bottom: Sunniberg bridge, Switzerland.
Benefits of concrete for bridge construction
4 Concrete Bridges
The structural forms that can be achieved with concrete are only limited by the imagination of the designer. This potential, that comes from designing in concrete, gives enormous scope to the architect and engineer to create elegant bridge structures that blend seamlessly with the surroundings, durably performing over long periods of time with minimum maintenance. Concrete unites both function and elegance in a safe, robust bridge, whatever the scale of the project.
Function and elegance
Striking features
Concrete can be moulded into any shape by using appropriate
formwork. This capability can be used to provide bespoke design
solutions to resolve specific constraints and deliver visual impact.
Alongside design potential, the architectural surface finishes that
can be created provide the opportunity for architectural expression
to blend with structural integrity. Concrete surface finishes add to
the overall visual impact of any bridge project, while at the same
time eliminating the need for cladding or painting thereby reducing
ongoing maintenance requirements.
Concrete bridges consistently win awards. The Supreme Award Winner of the Structural Awards 2006, presented by the Institution of Structural Engineers, went to Sungai Prai Bridge, Malaysia.
4 Concrete Bridges
Records can trace early use of concrete to as long ago as 7000BC.
It was regularly used by the ancient Egyptians, with current research put
forward by the Department of Materials Science at the Massachusetts
Institute of Technology arguing that the top levels at least of the great
Pyramids at Giza were formed from cast in situ concrete. Moving forward
within the ancient world, the Roman Emperor Hadrian used concrete to
build the famous wide span concrete domed roof over the Pantheon in
Rome in around 118 to 126 AD. The physical evidence is there for all to
see, handed down to us throughout history to confirm that concrete has
proved itself to be a very durable construction material.
Detailing for durability
The durability of concrete bridges is dependent on both the concrete
itself and the attention that is paid to detailing. Guidance on detailing
concrete is provided in a number of best practice documents, the two
most notable of which are BD 57: Design for Durability [1] published by
the Highways Agency in the UK and C543: Bridge Detailing Guide [2]
published by CIRIA (www.ciria.org.uk). These documents now form
mandatory requirements on some projects.
Modern innovations
Modern concrete technology has opened the way for ever more
imaginative structures. The innovation of high performance
concrete incorporated integrated properties that make it denser
when compacted, a viable option for engineers looking for robust
construction solutions. The dense nature of high performance
concrete is made even more attractive by its greater resistance to
physical or chemical attack, as well as its proven durability when
exposed to aggressive environments such as those created by
chemicals such as de-icing salt. As a result, properly constructed
modern concrete structures should stand the test of time as
successfully as their celebrated ancient forebers.
The success of any application of concrete comes with a thorough
understanding of how concrete works in its constituent parts, as
well as when all the elements are brought together in a structure.
Structural reinforcement, usually steel bars, is placed within concrete
to add tensile strength. The reinforcement in the concrete is
protected by the passive layer that forms on its surface due to the
naturally high pH environment of the cement matrix. The properties
of the concrete and the thickness of the cover to the reinforcement
are designed so that aggressive substances, such as chlorides from
de-icing salts, do not penetrate the concrete and break down the
passive layer, leading to corrosion of the steel reinforcement during
the life of the bridge.
Concrete mixes for high durability
A number of national and European design standards and
specifications(e.g. BS 5400, BD57/01, BS 8500 and BS EN 206)
[3, 1, 4, 5] set out the requirements for concrete construction,
identifying the required cover to reinforcement, cement
content, water/cement ratio and cement type. Following these
recommendations will ensure that the concrete is resistant to
carbonation and chloride ingress, providing an extended working life.
Concrete is a very appropriate construction material to use on
projects where the structure is to be subjected to unusually
aggressive ground conditions. High quality, low permeability mix
designs are available that will provide a resilient performance within
the most challenging environments. UK and European standards for
concrete, BS 8500 and BS EN 206, recognise concrete’s potential
in difficult environments, setting out minimum cement content,
maximum water/cement ratios and cement types to protect against
sulfates and acids in the ground.
The partial substitution of Portland cement with fly ash (fa) or
ground granulated blast furnace slag (ggbs) in the mix results in
concretes with high resistance to the ingress of chlorides from
de-icing salts or sea water.
Innovation has led to development of modern forms of concrete that
is free from any risk of alkali-silica reaction (ASR). ASR was a rare
occurrence found in a few early concrete bridges. In modern concrete,
ASR is prevented at the outset through the proper use of materials at
the concrete mix design stage.
Minimising maintenance
Well designed and constructed concrete bridges require only
minimum maintenance to keep them in good working condition.
CIRIA Guide C543 [2] contains good practice recommendations
for designing concrete bridges to minimise maintenance and
ensure longevity.
Particular attention should be paid to detailing the secondary
elements of bridge structures, such as bearings and expansion joints.
Integral construction, where the substructure is built monolithically
with the bridge deck, should be adopted where possible to ensure
maximum resilience and robust performance. An alternative option
to integral construction is to design inspection galleries into the
structure, to permit checking and maintenance of bearings and
expansion joints throughout the life of the bridge.
Built to last
Concrete Bridges 5
Concrete bridges come in all shapes and sizes. Designs can meet whatever functional, aesthetic and economic criteria are appropriate to the site location and needs of the client.
Versatility
CONSTRUCTIONTYPE
IN SITU
PRECAST
DECK TYPE SPAN RANGES/M
RC solid slab
RC voided slab
Prestressed voided slab(Internal bonded)
Incremental launching
Span by Span(Supported on launching truss)
Span by Span(Supported on scaffolding)
Segmental balanced cantilever
Arches
Inverted T beams cast into slab
M,U and Y beams with deck slab
Segmental balanced cantilever(Erected by crane)
Segmental balanced cantilever(Erected by lifting gantry)
Cable stayed bridges by balanced cantilever
Definite range Possible range extension
0 50 100 150 200 250 300 350 400
ARCHES
Arches are perhaps the oldest form of bridge
construction. They can be adopted over a large
range of spans.
Esplanade arch bridge, Singapore.
SLAB BRIDGE DECKS
Slab bridge decks are useful for short spans.
Designed with either solid or voided slabs, they
are usually constructed with insitu concrete using
traditional formwork and falsework systems.
Typical two span slab deck overbridge.
Figure 1: Types of concrete bridge construction with span ranges
6 Concrete Bridges
There are a number of different types of bridge decks (the top
surface of a bridge which carries the traffic) for designers to choose
from. The range of options means that there will always be a few
deck options to consider for any one site.
Bridges can be categorised in terms of span range. The current
limits to span ranges, shown in Figure 1, should only be treated as
guidelines, as the codes of practice adopted for loading and structural
design in conjunction with material availability will alter the upper
bound span ranges. The advance of material, design and construction
technologies are also likely to further increase these ranges over time.
CABLE STAYED BRIDGES Cable stayed bridges are appropriate for longer
spans. They can be designed for a huge range of
span and cable configurations.
River Dee cable stayed bridge, Wales.
THE STRESSED RIBBON
The stressed ribbon, a form of suspension bridge,
encases suspension cables within the concrete
deck. They are only suitable for use as
pedestrian bridges.
Stressed ribbon bridge, Ireland.
BOX GIRDERS
Box girders are used for spans from 40m up to
300m using either in-situ or precast concrete
segmental construction. Box girders produce
elegant and robust solutions.
Medway box girder viaduct, Kent.
INCLINED FRAME BRIDGES
Inclined frame bridges are constructed with the
supporting piers integral with the deck and at an
inclination to the vertical. They are ideally suited
across valleys or steep sided cuttings.
A1 Tyne bridge, Scotland.
EXTRADOS BRIDGES
Extrados bridges are a hybrid between a
conventional box girder deck and a cable stayed
bridge. A stiff deck is supported by cables at a
shallow inclination from short pylons.
MENN SUN extrados bridge.
BEAM BRIDGES
Beam bridges can be quick to erect over
existing roads, railways or rivers. Standard
precast beam types can cater for spans of
up to 50m.
A typical single span precast beam bridge.
Concrete Bridges 7
Fast constructionThe demands of clients and the very nature of the fast moving construction industry continually mean project targets are set for bridges where speed of construction is of the essence. Adequate pre-planning, precasting of elements and the use of appropriate technology in design and construction can make concrete the cheapest and fastest material for constructing durable, quality bridges. A number of techniques are commonly used to achieve fast construction.
8 Concrete Bridges
Chartist Bridge, Sirhowy Enterprise Way, Wales. Courtesy of The Concrete Society.
Broadmeadow Estuary Bridge, Ireland. The designers were able to take full advantage of the good early strength properties of concrete.
River Dee Viaduct, Wrexham.
Off-site manufacture
Construction time on-site can be reduced by precasting the concrete
elements either in a factory or alongside the bridge site. Examples
of this include precasting of complete structural elements or
prefabrication of reinforcement cages. When working on rail lines
where access times are restricted, complete deck elements can be
manufactured and slid, lifted or rolled into place. The designer will
play an important role in the development of such methods.
Sliding, launching and transporting
Bridges can be launched, slid or moved into place using
multi-wheeled transporters. This is a technique often used to
minimise disruption to road and rail networks during bridge
replacement or installation. The forward launching of concrete bridge
decks can be especially economic when the total deck length is more
than about 200m. The process lends itself to any construction that is
high, or over difficult or obstructed ground, such as roads, railways or
rivers. An alternative construction option for challenging locations is
a cast in situ concrete bridge formed using an appropriate falsework.
Jacked boxes
Precast concrete box culverts and pipes can be jacked beneath
existing embankments, removing the need to close the road or
railway above to construct a traditional bridge. Larger concrete box
structures, suitable for vehicular traffic, can also be jacked through
embankments. The boxes are formed in adjacent casting areas and
then pushed into the embankment using suitable jacking points. A
steel or concrete shield is used to support the advancing front face
beneath the embankment, while anti-drag systems reduce friction
between the box and the soil.
Modular bridges
The modular bridge system combines features of steel-concrete
composite, precast concrete beam, in-situ and segmental schemes
into a solution that can deliver the highest value for the majority of
bridge locations of medium-span bridges, usually in the span range
of 15m to 50m.
The modular system consists of relatively light, 2.5m long, precast
concrete shell units that can be easily transported to site for
assembly. Permanent prestressing cables are then placed within the
precast elements and covered by in-situ concrete to provide the
protection required. The construction methodology can be varied
to suit specific bridge sites and demands of the project programme.
Varying span lengths, carriageway widths, horizontal and vertical
curvatures and skew can be readily accommodated by the
match-cast shell units to provide an elegant solution for medium
span bridges.
Concrete Bridges 9
10 Concrete Bridges
Sustainable bridge design
The sustainability credentials of bridge construction materials are
becoming increasingly important as the environmental limits
to economic growth become apparent. Specifically, the need for
sustainable bridge construction relates to two main issues:
• Finitenaturalresourcesarebeingusedanddiscardedatarate
that the UK (and the world in general) cannot sustain.
• Theemissionscausedbytheconsumptionoftheseresources
are causing environmental degradation and are contributing
to global warming.
With a typical design life of at least 100 years, concrete is the most
durable material commonly used to build bridges of any form or size.
In environmental terms, it is useful to think of concrete as having
three phases of life – starting with its creation, its ongoing use in
bridge structures, and ending with the recycling of up to 95 per cent
of the concrete and steel reinforcement once the bridge has reached
the end of its viable use.
Production efficiency improvements
The environmental impacts of cement and concrete production have
been rigorously reduced and are is set to decrease further as the
industry continues on a £400m investment programme of energy
efficiency improvements and greater use of alternative fuels such
as scrap tyres to replace finite fossil fuels such as coal. Based on
1990 data, by 2010 the sector is on target to achieve a 25.6 per cent
energy efficiency improvement [6].
The local material
A key principle of sustainable bridge design and construction is that
a product should be consumed as near to the place of its production
as possible in order to:
• Minimisetheneedfortransporttositeandtheassociated
environmental, economic and social impacts.
• Supportthelocaleconomyandcommunity.
• Preventtheexportofassociatedenvironmentalimpactsof
production to another location.
The UK is highly self-sufficient in the materials needed for concrete
and there is generally a ready-mix plant within six radial miles of
every construction site in the country.
Blended cements
Concrete is made with cement. Cement production involves the
heating of blended and ground raw materials such as limestone or
chalk, clay or shale, sand, iron oxide and gypsum. Portland cement
is the most common cement manufactured in the world but the
cement industry is moving towards blended products that increase
the use of recycled materials. Blended cements suitable for bridge
construction are now widely available that contain a proportion of
industrial by-products, such as fly ash (fa) and ground granulated
blast furnace slag (ggbs).
Blended cements contribute towards sustainable bridge construction
through the use of waste products, while also producing a more
durable concrete that will make the bridge structure less susceptible
to chloride ingress.
Embodied energy
Engineers consider embodied energy and carbon dioxide emissions
from the use of all construction materials when planning, designing
and constructing a bridge.
Studies have been carried out on different forms of bridge structures
to assess both the energy consumed and the CO2 emissions
generated in their construction and use. The embodied energy
comparison shown in Table 1 (see page 11) demonstrates that across
the range of bridge forms concrete construction consumes the
least energy. The same conclusion is reached when comparing CO2
emissions.
Sustainability is a complex area encompassing environmental,
economic and social aspects that are intrinsically woven. With its
long life and minimum maintenance, concrete is a construction
material that brings these credentials to any bridge construction
project. Looking to the future, improvements are being explored
that will further enhance the sustainability agenda in favour of
concrete bridges when compared to other materials. The cement
and concrete industry is taking the lead in evolving ever more
sustainable approaches to concrete construction.
The design of a bridge, as in any built environment project, has to take a long-term and strategic view. The responsibility of the design team lies not just in terms of the visual impact and functional performance of a road, rail or pedestrian bridge as a transportation structure. It is now essential that design teams develop crossing solutions that impact the earth as lightly as possible in terms of environmental footprint and sustainability, both during construction, and over the whole life of the bridge.
Table 1: Embodied energy (Gj/m2) for various structural forms and materials [7]
Energy Type Steel Concrete Composite
Minimum Viaduct 17.8 15.7 / 16.6 16.6
Girder 30.9 23.6 29.1
Arch 49.8 38.8 48.8
Cable stay 40.3 34.3 37.7
Average Viaduct 23.5 21.1 / 22.1 22.1
Girder 39.3 30.6 37.0
Arch 61.9 49.1 60.8
Cable stay 50.6 43.9 47.7
Maximum Viaduct 30.8 28.1 / 28.6 29.2
Girder 49.3 39.1 46.6
Arch 75.6 60.9 74.4
Cable stay 62.6 54.8 59.3
Concrete Bridges 11
Marine Way Bridge, Southport.
12 Concrete Bridges
High performance concreteThe ongoing development of high performance concrete provides opportunities for greater artistic expression in bridge design, as well as more durable and economic structures.
High performance concrete meets special criteria which cannot
always be achieved through conventional materials and normal
mixing, placing, and curing practices. The bridge design or specific
construction challenges may dictate enhancements to the
characteristics of the concrete, such as placement and compaction
without segregation, long-term mechanical properties, early-age
strength, toughness, volume stability, or service life in severe
environments.
Fibre reinforced concrete
Steel or synthetic fibres can be added to concrete to enhance the
toughness, ductility and energy absorption capacity under impact
of the bridge structure. Fibres in concrete can reduce the formation
and development of cracks in the bridge form due to early-age
plastic settlement and drying shrinkage. In addition steel and
macro-synthetic fibres can provide a degree of post-cracking
load-carrying capacity and thus reduced crack widths.
The application of fibre reinforced concrete to bridgeworks is usually
as a supplement to traditional reinforcement, in order to limit
shrinkage cracking or to provide enhanced impact resistance.
More information on fibre reinforced concretes can be found in
several technical reports [8,9].
Foamed concrete
Foamed concrete is a highly workable, low-density material that
can incorporate up to 50 per cent entrained air. It is generally self-
levelling, self-compacting and may be pumped. As a result, foamed
concrete is ideal for filling voids in bridges where access is difficult.
In most cases, higher density and strength mix (1400kg/m3 and
7N/mm2 respectively) is used in the layers near the road surface
when filling bridge arches, while lower density mixes (600kg/m3)
are employed at greater depths.
Major projects have been carried out using foamed concrete including
the repair of the 25 year old bridge deck of the Llandudno junction
and Deganwy flyover, in North Wales. The voids between the arches
and final road surface of the new Kingston Bridge over the River
Thames were also filled with foamed concrete.
The Medway Viaduct, Kent, utilised lightweight concrete.
High strength concrete
High strength concrete is continually innovating. In the 1950s 34N/mm2
was considered high strength, building up to compressive strengths of up
to 52N/mm2 being used commercially in the 1960s. More recently, it has
become standard practice for precast beam manufacturers to adopt
70N/mm2 concretes – an industry development welcomed by bridge
designers because of the permitted increased spans. A number of bridges
have now been constructed with ultra high strength concrete which can
achieve compressive strengths of up to 225N/mm2.
High workability concrete
The concrete used in bridgeworks will frequently be specified to have
high workability. This flexibility enables placing in the complex shapes and
congested details that may be encountered in a bridge of any size. The
workability of fresh concrete should be suitable for each specific application
to ensure that the operations of handling, placing and compaction can be
undertaken efficiently. European and UK standards for concrete, BS 8500 and
BS EN 206, give guidance on workability for different uses.
The handling and placing of concrete mixes can be considerably improved
by the use of cement replacement materials such as fly ash or ground
granulated blast-furnace slag. Admixtures such as water reducers and
superplasticisers also have beneficial effects on workability without
compromising the concrete’s other properties.
Lightweight concrete
Lightweight concrete can be produced using a variety of lightweight
aggregates, originating from the thermal treatment of natural raw
materials, such as clay, slate or shale, and manufacture from industrial
by-products such as fly ash.
The benefits of using lightweight concrete in bridge design and
construction include a reduction in dead loads (which generates savings
in foundations and reinforcement), a saving in transporting and handling
precast units on site and a reduction in formwork and propping [10].
No-fines concrete
No-fines concrete is used behind bridge abutments and in verges. It is
obtained by eliminating material from the normal concrete mix.
The single sized coarse aggregates are instead surrounded and held
together by a thin layer of cement paste to give the concrete its strength.
The advantages of no-fines concrete include lower density, lower cost
due to lower cement content, lower thermal conductivity, lower drying
shrinkage, no segregation and capillary movement of water. No-fines
concrete also gives better insulating characteristics than conventional
concrete because of the presence of large voids.
Self-compacting concrete
Self-compacting concrete (SCC) usually contains superplasticisers and
stabilisers in order to significantly increase the ease and rate of flow. By
its very nature, SCC does not require vibration. It achieves compaction
into every part of the mould or formwork simply by means of its own
weight without any segregation of the coarse aggregate. This construction
benefit makes it an ideal material for bridge construction.
Developed in Japan and continental Europe, SCC is now being increasingly
used in the UK where it offers faster bridge construction times, giving
increased workability and ease of flow around heavy reinforcement. It
also provides health and safety benefits as there is no need for vibrating
equipment which spares workers from exposure to vibration, and also
results in quieter bridge construction sites.
Water resistant concrete
Water resistant concrete repels the water and other fluids either above
or below ground. It is a high density concrete that incorporates fine
particle cement replacements, hydrophobic pore blocking ingredients or
waterproofing admixtures.
Concrete Bridges 13
The Flintshire (Dee Estuary) Bridge utilised concrete with strengths up to 70N.The Confederation Bridge in Canada used high-performance concrete to resist the corrosive action of salt water.
14 Concrete Bridges
Case studies
Byker Viaduct, NewcastleMature structure
Completed in 1978, the Byker Viaduct won The Concrete Society award for Historical Civil Structures in 2006.
The first use in the UK of match-cast joints for precast segmental construction, the viaduct incorporated many innovative techniques in its construction. The use of precast segments minimised disruption within the urban environment by reducing the site works and speeding up the viaduct’s construction.
Segments were cast in a precast yard located adjacent to the site, and then segments stored until they were required. Erection of the first segments was by crane, with a lifting frame then installed on top of the deck to erect the remaining segments.
Kingston Bridge widening, Kingston-upon-Thames, LondonHigh performance concrete
The project to widen the historic Grade II listed arch bridge over the River Thames utilised precast arch units with brick and stone bonded to the face. This project demonstrates the quality of finish that can be achieved by adopting precast concrete construction and the use of advanced concrete.
The project pioneered the use of foamed concrete as a fill material over arch structures. Its use in conjunction with lightweight structural concrete (Lytag) minimised the piling required for the widened structure.
Holmethorpe Underpass, RedhillFast construction
When a new road was required to open up an area behind an existing railway embankment, and only 92 hours was allowed for closure of the railway line, a concrete portal constructed off-site provided the ideal solution.
Cast between September and November 2004, the underpass structure was stored at the side of the embankment for the rail possession to start on Christmas Eve. After moving into position the embankment was rebuilt behind the abutments and the ballast and rails re-instated to allow the trains to run again.
The portal structure was lifted by a multi-wheel transporter unit and moved into position in line of the embankment.
Upper Forth Crossing at Kincardine, ScotlandLaunched bridge
This 26-span bridge, weighing over 32,000 tonnes and measuring 1.2 kilometres in length, is the second longest incrementally launched concrete bridge in the world. The design and construct contractor constructed the bridge deck on line in a construction yard established on the northern shore of the Forth at Kincardine. The completed bridge was jacked forward incrementally span by span over the river, using two 600 tonne hydraulic jacks.
The contractor incorporated many innovative solutions in the design and construction, including the use of large steel cased reinforced concrete monopiles for the marine piers and partial prestressing of the concrete deck with external tendons to share the loading between the prestressing and longitudinal reinforcement.
The availability of a disused power station site lent itself to the deployment of the incremental bridge launching methodology, enabling the new crossing to be constructed with minimal impact on the internationally important wildlife reserves around the Upper Forth.
With over 100 years of history, concrete bridges are an established part of the UK’s rural and urban landscape. Looking ahead, concrete bridge construction should continue to lead the way in the future, enabling aspirations embraced by the construction industry and society to create a more sustainable environment.
References1. Highways Agency: BD 57/01 Departmental Standard, Design for Durability, Design Manual for Roads and Bridges, Vol. 1, Section 3, Part 74,
Department of Transport, 2001
2. Report C543 - Bridge Detailing Guide, Construction Industry Research and Information Association, 2001
3. BS EN 206-1:2000: Concrete. Specification, performance, production and conformity, British Standards Institute, 2006
4. BS 5400: Steel, concrete and composite bridges — Part 4: Code of practice for design of concrete bridges, British Standards Institute,1990
5. BS 8500: Concrete — Complementary British Standard to BS EN 206-1, British Standards Institute, 2006
6. Key Issue: Climate Change, British Cement Association, 2006
7. Collings, D., An environmental comparison of bridge forms, Proc. ICE, Bridge Engineering, Vol 159, Issue BE4, 2006
8. TR63 – Guidance for the Design of Steel-Fibre-Reinforced Concrete, CCIP-017, The Concrete Society, 2007
9. TR65 – Guidance on the use of Macro-synthetic Fibre Reinforced Concrete, CCIP-021, The Concrete Society, 2007
10. Guide to the use of Lightweight Concrete in Bridges, CCIP-015, The Concrete Bridge Development Group, 2006
Further readingThe following Cement and Concrete Industry Publications (CCIPs) are available to provide further information on the use of concrete in bridge
construction. For more information on these and other publications, visit The Concrete Centre’s website at www.concretecentre.com/publications
• Fast Construction of Concrete Bridges, CBDG/014 TG5, The Concrete Bridge Development Group, 2005
• Guide to the use of Self-Compacting Concrete in Bridges, CCIP-003, The Concrete Bridge Development Group, 2005
• High Strength Concrete in Bridge Construction, CCIP-002, The Concrete Bridge Development Group, 2005
• Guidance on the Assessment of Concrete Bridges, CCIP-024, The Concrete Bridge Development Group, 2007
• Modular Precast Concrete Bridges, CCIP-028, The Concrete Bridge Development Group, due 2009
• Guidance on the use of Precast Concrete Arch Structures, CCIP 035, The Concrete Bridge Development Group, due 2009
Conclusion
Using local resources sourced from within the immediate local
environment helps bridge designers and contractors to deliver
sustainable concrete solutions for a wide range of bridge applications.
Durability, aesthetics, economic solutions, simplified construction and
rapid deployment techniques all contribute to making concrete the
best construction material for any bridge project, whatever the size,
form or intended use. Greater construction flexibility can be realised
through the many forms of concrete easily available nationwide,
making concrete an adaptable resource suitable for deployment for
even the most challenging of bridge types or construction sites.
Concrete Bridges 15
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any loss resulting from such advice or information is accepted by The Concrete Centre or its subcontractors, suppliers or advisors. Readers should note that the publications from The Concrete Centre are subject to revision from time to time and should
therefore ensure that they are in possession of the latest version.
Ref: TCC/02/08
ISBN: 978-1-904818-67-0
First published 2008
©The Concrete Centre 2008
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