Concrete Bridges

THE BENEFITS OF CONCRETE IN BRIDGE DESIGN AND CONSTRUCTION

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

www.concretecentre.com

The Concrete Centre

Riverside House,

4 Meadows Business Park,

Station Approach, Blackwater

Camberley, Surrey GU17 9AB

If you have a general enquiry relating to the design,

use and performance of concrete,

please contact our national helpline.

Email helpline@concretecentre.com

Monday to Friday 8am to 6pm.

Call 0845 812 0000

All advice or information from The Concrete Centre is intended only for use in the UK by those who will evaluate the significance and limitations of its contents and take responsibility for its use and application. No liability (including that for negligence) for

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