Stainless Steel in Bridges and Footbridges

Stainless Steel in Bridges and Footbridges

What is stainless steel?Stainless steel is an alloy of steel, chromium andeventually other elements such as nickel ormolybdenum. It is the chromium that renders thesteel stainless. In fact, by virtue of the chromium’sreaction with oxygen, the surface of stainless steelconsists of a self-protecting passive layer thatautomatically regenerates itself if damaged. The other alloying elements (molybdenum inparticular) further enhance this corrosion resistance.

According to its constituent elements and theirrelative percentages, stainless steel breaks downinto more than a hundred grades grouped intoseveral major categories that are found in Europeanstandard EN 10088. Thus, stainless steel may beferritic, austenitic, duplex or martensitic. Eachcategory has specific mechanical properties – suchas hardness, yield strength, tensile strength,elongation, etc. These properties are decisive in thechoice of a grade for one application or another.

Austenitic stainless steels are the most widely usedcategory and today still account for almost 70% ofstainless production. However, with the fluctuatingcost of nickel in particular, but also of molybdenum,use of the austeno-ferritic duplex category, with a lower content of alloying elements, is increasing.Today, it offers equivalent or even superior quality in terms of corrosion resistance and its superiority in terms of mechanical performance makes it a particularly competitive material in the bridges and footbridges market.

From lianas to stainless steel

The building of bridges to cross a river ora ravine, to join the two banks of a river,the two sides of a valley or even two districtsof the same town, goes back to very ancienttimes. The first were built using lianas, treetrunks, stone slabs. Since ancient times,wooden bridges have enabledexperimentation with various designs andwere followed by stone bridges, which havethe advantage of better resistance to fire.In the industrial age, the use of iron andthen of steel gradually enabled the designof bolder, more innovative crossings.New techniques, such as suspension, weredeveloped.

At the end of the 18th century, theCoalbrookdale bridge in England gave iron itsplace in the history of bridge-building. Later,the Golden Gate Bridge, completed in 1937,which is almost 2 kilometres long and crossesSan Francisco Bay, set the long-held recordfor the world’s largest suspension bridge.

Steel is now in general use for bridgeconstruction but the use of stainless steelis relatively recent, 10 to 15 years. Initially used principally for its anti-corrosionproperties in safety components – guardrails,handrails… – stainless steel is now foundin structural components, whether inthe deck – in the form of beams and weldedplate sections, tie-rods – or in the suspensionsystems – in the form of stays, cables andpylons. It is also present in concretereinforcement.

Passerelle Pùnt da Suransuns

There is not one stainless steel but severalcategories of stainless steels, each of whichcomprises several grades. Each category hasits properties, and each grade has its specificcharacteristics that must be taken intoaccount according to the type of structure,its design and the nature of the atmosphere.

What grades for a bridge?

The choice of grade is influenced by thedegree of atmospheric corrosiveness and bythe mechanical properties – yield strengthand tensile strength in particular. The morecorrosive the atmosphere, chloride-laden


for example, the greater must be the steel’scorrosion resistance. The greater the bridge’sspan, the more demanding the requirementin terms of mechanical performance.

Stainless steels used for bridges andfootbridges belong primarily to twocategories of stainless: austenitics andausteno-ferritics, also known as duplex,which combine excellent corrosion resistanceand elevated mechanical performance.

More rarely, and for specific applications,certain grades of ferritic stainless are employed.

Courtils footbridge over the Canal d’Orléans at Chécy

Stainless steel in bridge andfootbridge applications

Courtils footbridge over the Canald’Orléans at Chécy, France, 2004

■IIII Arched footbridge, welded plate girderin 316L (1.4404) stainless steel

■IIII Reduced maintenance

The Courtils pedestrian footbridgeconnecting the towpath to Chécy is inreality two bridges: the one is a galvanisedsteel beam bridge, crosses the River Censand the other, in stainless steel, describesan arch above the Canal d’Orléans.The second comprises two workshop-prefabricated arches: U-shaped weldedplate girders produced from 12 mm thick316L (1.4404) stainless steel plate andjoined by welding. The arches areconnected by triangular box girdersin 3 mm thick plate onto which gratingsare secured. The use of stainless steel isjustified by the assurance of maintenance-free operation.

Architects: Espace / Brigit de KosmiConsulting engineers: Terrell Rooke associés /Zbigniew Koszut ing.Steel construction: OMSContracting authority: Communauté de communesde l’agglomération orléanaise

Table of grades suited to bridge and footbridge applications,

classified according to their degree of corrosion resistance

European standard US / ASTM standard Category Environmental resistance

1.4462 S32205 duplex highly corrosive (marine and industrial)

1.4404 316L austenitic highly corrosive1.4401 316 austenitic corrosive to highly corrosive1.4362 S32304 duplex corrosive1.4062 S32202 duplex corrosive to slightly corrosive1.4307 304L austenitic slightly corrosive1.4301 304 austenitic slightly corrosive1.4618 17-4Mn austenitic slightly corrosive1.4003 ferritic non-corrosive1.4017 ferritic non-corrosive

Cala Galdana Bridge, Menorca,Spain, 2005

■IIII A road bridge with two self-anchoredarches in 2205 (1.4462) duplexstainless steel

■IIII Technological innovation and durability

The length of the structure is 55 m, with a free span of 45 m. It comprises two carriageways each 3.5 m wide and a 2 m wide walkway on each side. Two parallel arches with an intermediatedeck constitute the main structure, entirelybuilt of 2205 (1.4462) duplex stainless platein thicknesses of 10 to 25 mm accordingto the component. The arches consist oftriangular box girders with a central weband rise 6 m to the apex. They areconnected to the two longitudinalrectangular box girders of the deck.The framework components wereassembled into structural elements andthen transported to the site in eight sectionsfor welding in situ. The finish is obtainedby shotblasting the surfaces. In additionto a corrosion-resistant material beingdictated by the saline atmosphere,the choice of stainless steel satisfiesthe criteria of environmental friendliness,great durability, minimal maintenanceand technological sophistication.

Design: PedeltaSteel construction: AscamonContracting authority: Consell Insular de Menorca

Cala Galdana Bridge, Menorca

2 /3

Cross section

Bridge elevation

Waldeck-Rousseau Bridge at Saint-Brieuc, France, 1998

■IIII Urban road bridge, 316L (1.4404) and 304 (1.4301) stainless steel boxgirder deck

■IIII Reduced cost of maintenance, corrosion resistance

It is one of the first road bridges, if notthe first, to be built with a stainless steelstructure. 18 m wide and with a 40 m span,it comprises a central stainless steel spanbetween two reinforced concrete spansand has an asphalt surface. The structureis designed like a steel pillow, stretched

beneath the road, whose dual curvatureproduces maximum inertia at the centre. The more exposed external plates are in 316L (1.4404) stainless steel, while the interior of the deck is in 304 (1.4301)stainless. All the steel components werejoined by welding.Stainless steel’s corrosion resistance was a determining factor in the choice of this material, as was the prospect of substantial maintenance savings.

Architects: Jean Guervilly (DGB)Consulting engineers: Groupe Alto/Marc MalinowskySteel construction: Saint-Malo NavalContracting authority: ville de Saint-Brieuc

Austenitic stainless steels

They contain nickel and/or manganese and/ormolybdenum. This is where one finds thealloys containing the most nickel (up to 13%),which enhances resistance to so-calledcrevice corrosion and makes the stainlesssteel more ductile. The most-used gradesin the market segment in which we areinterested here are 304 (1.4301) and 316L(1.4404) but 304L (1.4307) and 316(1.4401) are also encountered. Grade 17-4Mn (1.4618), a low-nickelaustenitic in ArcelorMittal’s “200 series”,is also suited to a slightly corrosiveenvironment.

All these grades have similar mechanicalproperties with a tensile strength Rm = 620 to 670 MPa and a yield strength Rp0.2 = 310-330 MPa for coils and a tensilestrength Rm = 500 to 600 MPa and a yieldstrength Rp0.2 = 200-250 MPa for plates.

The choice between these grades is madeaccording to the structure’s environment,in particular atmospheric quality (pollution,sea air, thermal cycle, precipitation). So, ina relatively pollution-free rural environment,one can opt for 17-4Mn (1.4618) stainless,whereas by the coast one will choose 316L(1.4404) stainless.



Waldeck-Rousseau Bridge at Saint-Brieuc

Cutaway axonometric projection ofthe steel structure of the deck

It is possible to combine these grades,keeping the most corrosion resistant gradefor those parts exposed to the open air anda less resistant grade for the internal partsof the structure. This is the solution adoptedfor the Waldeck-Rousseau bridge at Saint-Brieuc, which combines 316L (1.4404)stainless and 304 (1.4301) stainless.

Austeno-ferritic or duplex stainless steels

Duplex stainless steels are characterised bya dual-phase austenite and ferrite structure.Their low percentage nickel content makesthem a very competitive material.

ArcelorMittal advocates three gradesfor bridges: – 2205 (1.4462) duplex – 22% Cr, 5% Ni;– 2304 (1.4362) duplex – 23% Cr, 4% Ni;– 2202 (1.4062) duplex – 22% Cr, 2% Ni.

These grades have the characteristic ofcombining elevated mechanical propertieswith corrosion resistance that is often similaror even superior to that of austenitics.In terms of mechanical properties for flat products, tensile strengths (Rm) of 840 MPa and yield strengths (Rp0.2) of 620 MPa are achieved on coils, and 650-750 MPa and 450-550 MParespectively on plates.

While the processing of duplex appears morecomplicated than that of austenitic stainless,its mechanical qualities enable the use ofthinner plate thicknesses than those usedfor other stainless steels.

In terms of corrosion resistance, 2202(1.4062) duplex is positioned between the304 (1.4301) and 316L (1.4404)austenitics, 2304 (1.4362) duplex isequivalent to 316L (1.4404) and 2205(1.4462) duplex, which contains 3%molybdenum, has even greater performance.The choice between these grades isinfluenced by the structure’s environment andthe construction methods employed inerecting the structure.

Ferritic stainless steels

They correspond to ArcelorMittal’s Kararange. Two grades – K03 (1.4003) andK31 (1.4017) - are apt to be used in crossingstructures. The tensile strengths (Rm) ofK03 and K31 are 510 MPa and 650 MParespectively and their yield strength (Rp 0.2) is 370 MPa. Easily weldable, these stainlesssteels are grades that can be used bare(K31 in a non-corrosive atmosphere)or painted or coated to further enhancetheir longevity (K03/K31). In certaincarefully selected cases, this categoryof stainless steel is very competitive.

4 /5

Piove di Sacco Bridge, Padua

Piove di Sacco Bridge, Padua, Italy, 2006

■IIII Dual-arch road suspension bridgein 2304 (1.4362) duplex stainless steel

■IIII Durability and reduced maintenance

To span the 120 m distance, the deckis supported by two 1300 mm diameterarches made of 12 to 26 mm thick 2304(1.4362) duplex stainless steel plate; thisrepresents 110 tonnes of stainless steel. The deck beams are 1000 mm highdouble-T welded plate beams in steelgrade S355 (250 t) in conjunction with acomposite deck and casing in 304 (1.4301)stainless steel.

Architects: Progeest / Enzo SivieroDesign engineers: Provincia de Padova /Silvio CollazuolExecution design engineer: TreEsse / C. Berto;Seteco ingeneria / Pierangelo Pistoletti(structures)Steel construction: CastaldoContracting authority: province of Padua

Which products for which applications?

Stainless steel can be found in all or part ofa bridge or footbridge. It is commonly usedin protection components – handrails andguardrails – as well as in the stays ofsuspension bridges, cables and tie-rods. It isalso advocated for the deck and anchoragecomponents, particularly in the case ofstructures built in marine and pollutedatmospheres. It is produced in the form ofbars, wire, rod, sheet and plate, as well asfinished products such as tubes and concretereinforcement.

Tubes and grilles

Handrails and guardrails – made of tube,sheet, expanded metal, perforated metalor woven wire – are very often produced instainless steel and the most commonly usedgrade is 316L (1.4404) in the austeniticcategory. For these applications, this gradehas the advantage of offering excellentresistance to corrosion and other attacks,even in thin gauges of steel. Its uniformappearance does not deteriorate,it is smooth and soft to the touch. Lastly,it is simple to clean.

Plates and welded plate sections

There is a great variety of bridges andfootbridges; they represent a wide rangeof constructional designs. However,the most-used stainless steel product inthe execution of these structures is plate.Relatively easy to process, it enables theproduction of welded plate sections and boxgirders. Thus, plates welded together willtake the form of a barrel arch here, of apillow there, of a triangular box girderelsewhere, of a castellated beam or evenof a skin. The components are cut, bent, formed,welded, finished, largely in workshops usingspecialist tools and techniques. Plates aregenerally arc-welded and the welds arethen cleaned and descaled. The formedcomponents are transported to the sitefor assembly and erection.

Cables, stays and tie-rods

Suspension and load transfer components,they also provide for the tensioning of thestructure. As in the case of plate, stainlesssteel’s corrosion resistance and its mechanicalperformance are essential, particularly inthe case of structures in marine and pollutedatmospheres. The use of stainless steel alsoenables construction using relatively thincomponents.



Simone-de-Beauvoir Footbridge, Paris

Simone-de-Beauvoir Footbridge,Paris, 2006

■IIII Steel footbridge, with 316L (1.4404)stainless steel guardrails

■IIII Slenderness and strength

The Simone-de-Beauvoir footbridge is anew crossing in Paris, suspended abovethe Seine between the French NationalLibrary and the Bercy gardens. The elegantfootbridge undulates with a gentle rhythm.It is bordered by guardrails comprisingstainless steel mesh – visible andreassuring but nevertheless transparent –installed between the handrail and astainless steel tube near deck level. Thecable mesh stretches between two rails,upper and lower, in the form of tube, all in 316L (1.4404) stainless steel.Here, the stainless steel componentscombine slenderness and strength.

Architects: Dietmar FeichtingerConsulting engineers: RFR, structural designerSteel construction: Eiffel construction métallique, main contracter; Joseph-ParisContracting authority: mairie de Paris

6 /7

Saint-Lô Footbridge, France Granite Footbridge, la Défense

Saint-Lô Footbridge, France, 2001

■IIII Footbridge with carbon steel structureand stainless steel formwork

■IIII Competitive cost and uniformity ofappearance

The construction of this footbridge formspart of a larger redevelopment project onthe banks of the River Vire. It establishesa 67 m pedestrian crossing – with a 51 mspan between the supports of the mainarches – thus connecting the station to thetown centre. Its structure consists principallyof two inclined arches and two tubularstringers interconnected by IPE 220 beams.These beams support the concrete slabpoured into 0.60 mm thick grade 304(1.4301) stainless steel permanentformwork. The entire steel structure,including the stainless steel formwork,is painted in white enamel, thus preventingdirect contact between the two types ofsteel. The choice of stainless steel was guidedhere by the need in this location for acorrosion-resistant material at competitivecost. Furthermore, it offered a perfect finishon the lower face.

Landscape architect: François BrunConsulting engineers: Terrell Rooke associés /Zbigniew KoszutSteel construction: OMSContracting authority: Saint-Lô conurbation

Granite Footbridge, la Défense,France, 2007

■IIII Suspended steel footbridge, cables,stays and handrail in 316L (1.4404)stainless steel

■IIII Strength and slenderness

In this footbridge, 316L (1.4404) stainlesssteel is employed in structural componentsand safety components (handrail, lift gate).Comprising twenty-six carbon steel boxgirders, the deck, once raised, was pre-stressed by tensioning stainless steelcables and stays; three ground supportsanchor the structure.The footbridge, which is 90 m long and 4.5 m wide, forms a curve at the second-floor level of the Granite tower. It thus provides a unique walkway,suspended among the towers.Complemented by vertical circulations, it connects the slab to the town’s naturalground level.

Architects: Dietmar FeichtingerConsulting engineers: Schlaich Bergermann undPartnerSteel construction: ViryContracting authority: EPA Seine-Arche

Cross section

Perspective view

High-performance designand efficient execution


Technical characteristics and aestheticquality of structures

Corrosion resistance, very good tensilestrength, high yield strength: the choiceof stainless steel is a guarantee of qualitywith regard to bridge construction.Its properties enable compliance with themost demanding technical requirements:long span, lightweighting of structures,seismic performance. It can be used bare,even in very harsh environments suchas coastal or industrial zones. Its Young’smodulus-to-density ratio makes it possibleto combine lightness and rigidity and thusgive birth to slim, slender structures.The benefits arising from the use of thismaterial also frequently engender majorsavings that ultimately can be offset againstits capital cost.

Pedro Arrupe Footbridge in Bilbao

Pedro Arrupe Footbridge in Bilbao,Spain, 2003

■IIII Box girder structure footbridge in 2304(1.4362) duplex stainless steel

■IIII Corrosion resistance and aestheticquality

Located in Bilbao’s flagship district, closeto the Guggenheim museum, the PedroArrupe Footbridge has the appearanceof being built entirely of stainless steelas much in order to satisfy aestheticconsiderations as to withstand the salinityof the Bay of Biscay. The deck is designedas an open box girder, constructed of20 mm thick 2304 (1.4362) duplex stainlesssteel plates bent into a “U” shape, insidewhich the internal frame made ofweathering steel is located. Thecombination of these two steels requiredparticular care. The transverse bracingframes support the concrete slab pouredinto galvanised steel forms. The entire deckis clad with Lapacho, a Brazilian wood.The structure is 142 m long betweenabutments and comprises a central spanand four pairs of ramps.

Architect: Estudio Guadiana / Lorenzo FernándezOrdóñezStructural designer: IdeamSteel construction: UTE Ferrovial-URSAContracting authority: Bilbao Ria 2000

Speed of execution and economicalconstruction

To a great extent, stainless steel componentsare prefabricated and assembled inworkshops, then transported to the site forerection in situ. They offer the advantage ofprecise execution, computer-controlled fromthe design of the component through to finalassembly, which shortens and simplifies thesitework phase and enables better controlof the construction timetable. The inconvenience caused by theconstruction operation is reduced and thereis less disruption to traffic. The erection of the Charvaux footbridge,for example, lasted two weeks and wasperformed alongside the old footbridge thatit replaced. The crossing was kept open atall times and the disruption caused lasted onlya short time.

8 /9

Charvaux Footbridge, Andrésy

Charvaux Footbridge, Andrésy, France, 2000

■IIII Single-arch suspended footbridge in 316(1.4401) stainless steel

■IIII Maintenance savings, longevity and uniform appearance

The Charvaux footbridge replaced a dangerous dilapidated footbridge. It spans 33 m above a busy road to connect two districts. Its structure, consisting entirely of passivated satin-finish 316 (1.4401) stainless steel, comprises a triangular section variable inertia parabolic arch and cross-bracing stays supporting the footbridge’s curved deck by way of three transverse beams; bracing cables installed beneath the deck balance the loads. The arch and the deck provide horizontal stability. The deck comprising cross beams and longitudinal girders is covered with Ipe wooden decking; it was manufactured in four sections in a production shop and then assembled in situ. The bridge was erected over a period of a fortnight. The stainless steel solution was selected in conjunction with the town council, for reasons of longevity and minimal maintenance. Moreover, it affords the structure a uniform appearance as all of the components, including the guardrail fittings, are in stainless steel.

Architects: Hubert & Roy / Michel RoyConsulting engineers: Groupe Alto / Marc MalinowskySteel construction: OMSContracting authority: Andrésy town council

Axonometric projection

Arco di Malizia Bridge, Siena, Italy, 2005

■IIII Single-arch road suspension bridge in2304 (1.4362) duplex stainless steel

■IIII Durability and reduced maintenance

This 15.8 m wide road bridge spans 51.5 m. Its weathering steel deck issuspended from a centrally-positionedlongitudinal arch, which thus separatesthe opposing traffic flows.This arch consists of five cylindricalelements, 10.7 m long and 820 mm outside diameter. They are produced from 35 mm thick 2304 (1.4362) duplexstainless steel plate, longitudinally arc-welded and formed. Pre-assembly of the five elements was performed on site by arc-welding, prior to erection.Two shotblasting operations, in theproduction shop and then in situ, ensure a flawless finish.

Architect: Paola D’OrsiDesign engineers: Raffaello FontaniExecution design engineer: Seteco ingeneria /Pierangelo PistolettiContracting authority: Siena city council


Arco di Malizia Bridge, Siena

An enduring material

Stainless steel’s strength is a guarantee oflongevity. Neither its mechanical propertiesnor its appearance deteriorate. It withstandsheavy loads and, to a certain extent,vibrations, impacts and elevated tensilestresses.The risks of deterioration of the materialare very low in the case of normal use.With regard to ad hoc maintenanceoperations, however, it must be ensured thatthe use of certain products such as road saltor maintenance products containing chlorineis compatible with the selected grade ofstainless steel.

Minimal maintenance

Stainless steel’s natural corrosion resistanceand its mechanical properties considerablyreduce maintenance operations and byextension their cost during the structure’soperating life. This advantage is essential,particularly in the case of long-span bridges,equipped with tall masts, where inspectionand access to components are sometimesextremely difficult. On more traditionalstructures, the benefit is still significant:renovating or repainting all or part of a bridgenormally requires that traffic flows on thebridge be suspended or subject to majorrestrictions. Reducing this type of operationas much as possible is essential, particularlyat crossings that already naturally constitutetraffic choke points.

In the case of Stonecutters Bridge, thestructure’s longevity has been assessedas 120 years without any maintenanceoperation on the stainless steel components;this criterion carries great weight in thechoice of material.

Longevity and reducedmaintenance

10 /11

Furthermore, in cases in which projectfunding is particularly tight, it is alwayspossible to restrict the use of stainless toexternal parts and to use a carbon steel forthe internal, and therefore protected, parts.This is the choice that was made for thePedro Arrupe footbridge in Bilbao, whosestructure consists of carbon steel. This hybridsolution enables the initial construction costto be reduced. It simply requires someprecautions in design and construction: thetwo types of steel must never, under anycircumstances, come into direct contact andaccess to the structure's internal parts mustbe possible in order to conduct regularinspections.

An economic solution


A bridge or a footbridge is a majorinvestment. However, the expense of itsconstruction and maintenance will varyaccording to the materials chosen for itsdesign and construction.

Analysis of the cost of such a structure isonly meaningful if it includes all costs relatedto its construction, its operation and itsdeconstruction, over its entire lifetime, whichin the case of bridges and footbridges shouldexceed 100 years.

In the case of stainless steel, this approachcompensates for the higher capital costlinked to the choice of material:ultimately, it is offset, in whole or in part,by the benefits obtained in operation.

Stonecutters bridge à Hong Kong,

12 /13

Stonecutters Bridge, Hong Kong,China, 2010

■IIII Cable stayed highway bridge usingstainless steel on the towers. Below deck level outer layer of concretereinforcement is 304 stainless steel(1.4301). The upper part of the tower is a composite structural section using an inner concrete core and an outer2205 duplex stainless steel skin(1.4462).

■IIII Reduced maintenance, corrosionresistance, economical

This highway bridge due for completionin 2010 forms part of the route connectingTsing Yi and Cheung Sha Wan. It is a cable-stayed bridge employing a semi-fancable configuration, it extends for a lengthof 1596 m with a 1018 m main spanbetween two immense masts that rise 296 m above sea level, of which more than 200 m is above deck level.The upper 120 m of these conical masts is a composite structural section of an innerreinforced concrete core and an outer skinof 20 to 25 mm thick 2205 (1.4462) duplexstainless steel plates. In the lower part of

the tower (below deck level) the concretereinforcements are in 304 (1.4301) stainlesssteel. The skin is structural, since itcontributes to the distribution of loadingsbetween the masts and the foundations.The choice of 2205 (1.4462) duplexstainless steel to clad the masts satisfies adual technical and economic requirement:built for a service life of at least 120 years, a material that is both long-lasting andmaintenance-free was essential. This skinmust withstand particularly high loadsprincipally due to winds because thestructure is in a typhoon belt. The pollutedmarine atmosphere called for a highlycorrosion resistant stainless steel. Finally,the uniform matt finish specified is obtainedby beadblasting the plate.To date, it is the world’s largest use ofstainless steel for this type of structure.

Design: Dissing+Weitling arkitektfirma a/s, Flint& Neill Partnership, Halcrow Group, Shanghaiconstruction engineering groupDetailed structural design: ArupContracting authority: Hong Kong Departmentof Highways

Stonecutters Bridge, Hong Kong

Environmental issues now constitute someof the parameters that must be considered inany construction project, including bridges.

Reduced consumption of materials

The method of designing and manufacturingsteel components – computer-aided designand workshop prefabrication – optimisesthe quantity of material used and generatesa minimum of waste which, moreover,is recovered and recycled. The highperformance afforded by stainless steel’smechanical properties renders it a graceful,lightweight solution.

Environmentally friendly

Stainless steel is an environmentally inertmaterial: in particular, it does not releaseany element that could harm its environment.Being rust-resistant, it does not require anyspecial maintenance, unlike a painted material,which must regularly be stripped andrepainted: two operations that are liable topollute the rivers being crossed or thesurrounding air.

Recyclable and recycled

All ArcelorMittal stainless steels are producedthrough the electric-arc process, 100%from recycled scrap. A material that is totallyrecyclable at the end of its life, it isextensively recycled. All ArcelorMittalStainless Steel Europe, ArcelorMittal Industeeland ArcelorMittal Stainless Tubes Europeproduction plants operate under the ISO14001 standard.

Environmental considerations


Suransuns Footbridge

Suransuns Footbridge, Switzerland,1999

■IIII Stress ribbon footbridge in 2205(1.4462) duplex stainless steel and316L (1.4404) stainless steel

■IIII Corrosion resistance, slendernessand simplicity

The Suransuns footbridge providesa continuation of the ancient Roman ViaMala in the form of a flexible, slenderribbon, connecting the two sides ofthe gorge at the bottom of which flowsthe Hinter Rhine: 40 m span. It consists offour 2205 (1.4462) duplex stainless steelribbons, joined in pairs by means of strapsin the same steel. A guardrail post,a 16 mm diameter 316L (1.4404) stainlesssteel tube that also secures the naturalstone decking through which it passes,is bolted to each strap; a flat welded to theupper end of the tubes forms the handrail.Concrete abutments on each side ofthe gorge provide for anchorage andtensioning of the structure by means oftension rods. The stainless steel gradesselected withstand salt spray from thenearby main road. The steel, stone andconcrete harmonise with the landscape.

Architect: Jürg ConzettConsulting engineers: Conzett, Bronzini,Gartmann AGSteel construction: RomeiContracting authority: Verein KulturRaum Via Mala

Inspirational

Steel in general, and stainless steel inparticular, is often appreciated for thefreedom of form that it enables. It permitsbold innovation that is often of value inresolving project-related constraints. Forexample, the Charvaux footbridge is afunctional solution that is both economicaland innovative; as is the Stonecutters Bridge,in a very different register, with its conicalmasts clad in stainless steel over a height ofmore than 100 metres.Furthermore, stainless steel is easily combinedwith other materials: whether it be the timberthat is often found as decking on footbridges– those of Bilbao and Charvaux are examples– or stone, as at Via Mala, or even concreteand asphalt in the case of road bridges.Other steels are not excluded, as witnessthe galvanised steel gratings of the Chécyfootbridge or the carbon steel main structureof the Saint-Lô footbridge.Lastly, stainless steel offers a high-qualityappearance and a wide range of surfacefinishes, from matt to bright, as-rolled tomirror, that should be appraised on the basisof each type of component.

In harmony with the landscape

The visual unobtrusiveness that steel canconfer favours the integration of thestructure into the landscape in which itis employed, particularly in respect ofthe framework. The Via Mala suspensionfootbridge in Switzerland – a simple ribbonbetween two banks – illustrates thisperfectly.

14 /15

Marina Bay Pedestrian Bridge, Singapore

Architectural freedom

Marina Bay Pedestrian Bridge,Singapore, 2009

■IIII Tubular structure footbridge in 2205(1.4462) duplex

■IIII Corrosion resistance, aesthetic quality,innovation

The structure of the Marina Bay PedestrianBridge consists of a reverse double helix –symbolising a DNA molecule – thatsupports the footbridge and defines itsvolume. The two spirals constructed of2205 (1.4462) duplex stainless steel tubesare interconnected, creating a sort oftubular lattice girder, thus distributingloadings. The deck is inserted into thisstructure. Five platforms punctuate thefootbridge, providing viewpoints lookingacross the bay.The 280 m long walkway is partiallyprotected from sun and rain by theprovision of a steel and glass meshcanopy.

Architects: Cox Group + Architects 61Consulting engineers: ArupSteel construction: TTJ Design & EngineeringContracting authority: Urban redevelopmentauthority of Singapore

ArcelorMittal’s offer

ArcelorMittal Stainless EuropeAutomotive & Industry Division(Sheets, flat products) Tel.: +32 89 30 19 66Fax: +32 89 30 19 07Contact: [email protected]/stainlesseurope

ArcelorMittal Stainless EuropeSpecialities Division(Sheets, flat products) Tel.: +33 (0)3 85 85 75 39Fax: +33 (0)3 85 85 79 55Contact: [email protected]/stainlesseurope

ArcelorMittal AncervilleStainless Tubes Europe(Tubes)Tel.: +33 (0)3 29 79 90 25Fax: +33 (0)3 29 79 90 40Contact: [email protected]/stainlesstubeseurope

ArcelorMittal Industeel(Thick sheets)Tel.: +32 499 56 40 40 / +33 (0)3 85 80 58 51Fax: +33 (0)3 85 80 51 77Contacts: [email protected] /[email protected]

ArcelorMittal Distribution (AMD)Tel.: +33 (0)3 26 84 67 02Fax: +33 (0)3 26 84 67 09 Contact: [email protected]/distribution

For further information

ArcelorMittalBuilding & Construction Support Tel.: +33 (0)1 71 92 16 86Fax: +33 (0)1 71 92 24 97www.arcelormittal.com

ConstructaliaEmail: [email protected]

Websiteswww.euroinox.orgwww.worldstainless.org

Publications– ArcelorMittal, Building & Construction SupportStainless Steel in Construction, 2007

– ConstruirAcier (ex-Otua), Puteaux, FranceBulletins Ouvrages métalliquesn° 2 (2002), n° 3 (2004) et n° 4 (2005)

– Euro inox, Bruxelles, BelgiquePedestrian Bridges in Stainless Steel, circa drei, Munich (Allemagne), 2004

– 30 Bridges, Matthew Wells, Laurence King Publishing, London, UK, 2002

Photo creditscover: Pont Arco di Malizia à Sienne,

© ArcelorMittal;

p. 1: Pùnt da Suransuns, © Conzett,

Bronzini, Gartmann AG;

p. 2: Brigit de Kosmi;

p. 3: DR;

p. 4: Jean-Marie Monthiers;

p. 5: ArcelorMittal, DR;

p. 6: Jo Pesendorfer, David Boureau;

p. 7: DR, Antonin Chaix;

p. 8: DR;

p. 9: Hervé Abbadie;

p. 10/11: ArcelorMittal;

p. 12/13: Arup;

p. 14: Conzett, Bronzini, Gartmann AG;

p. 15: Arup/Cox Architects & Planners.

Publication Building & Construction

Support with the assistance of

Eve Jouannais for copywriting and

editing.

Translation Tom Bishop.

Graphic design Bärbel Müllbacher.

Printing Qatena.

ArcelorMittalBuilding & Construction Support5, rue Luigi-CherubiniF-93212 La Plaine-Saint-DenisTel.: 33 (0)1 71 92 16 86Fax: +33 (0)1 71 92 24 97www.arcelormittal.comwww.constructalia.com

Documents

Stainless Steel in Bridges and Footbridges