Architectural Teaching Resource

STUDIO GUIDESecond Edition

c/PLEX Building:

Alsop Architects Ltd

The Steel Construction Institute is an independent,membership based organisation which was founded in1986 to develop and promote the effective use of steel inconstruction. Having developed a highly valuedframework for engineers, it is now involved in a numberof research programmes focused on architectural issuesincluding environmental projects.

For membership details (including student membership)and further information on publications and courses,please contact the Membership Manager.

The Steel Construction Institute Silwood Park Ascot BerkshireSL5 7QN

Tel +44 (0) 1344 623345 Fax +44 (0) 1344 622944 E-mail reception@steel-sci.comwww.steel-sci.org

www.steelbiz.org – the 24 x 7 online technicalinformation system for steel design and construction.

FOREWORD

ISBN 1 85942 138 5

Publication Number SCI P167

© The Steel Construction Institute 2003

Corus Construction Centre

Corus Construction Centre is an information source fordesigners and users of steel in the construction business.It provides a fast, efficient, ‘one-stop’ technical supportservice across all construction and construction-relatedproducts and applications. It can be contacted on asingle hotline number, 01724 40 50 60.

Corus Construction Centre PO Box 1 Scunthorpe North Lincolnshire DN16 1BP

Tel +44 (0) 1724 405060 Fax +44 (0) 1724 404224 E-mail corusconstruction@corusgroup.comWebsite www.corusconstruction.com

Front Cover:c/PLEX, West Bromwich

c/PLEX represents a radical gesture for communityarchitecture, born from the conviction that architecture can be acatalyst for regeneration and renewal. The client, Jubilee Arts,has long being a champion of the cause – using arts as a sourceof community renewal and social and economic regeneration.

The cover picture shows the ‘Sock’, a large sculptural elementwithin the external envelope of the building. The ‘Sock’contains three floor levels, which are linked by a snaking ramp.The ‘Sock’ has a structural steel frame with composite concretefloors constructed using steel decking.

Scheduled for completion in 2005, c/PLEX represents both astarting point and an opportunity for the people of WestBromwich, improving the town’s eroded sense of identity.

This Studio Guide, which is also available in anelectronic format, provides an overview ofcommon structural steelwork solutions andcomplements the British Steel ArchitecturalTeaching Programme distributed to all Schools ofArchitecture in the UK in 1996.

The Architectural Teaching Programmecomprises 36 lectures, over 1000 slides, videosand computer programmes, and provides acomprehensive review of the architecturalaspects of structural steelwork.

It is intended as an educational resource forarchitectural and engineering students and is asimple reference for use in practice.

General structural design information ispresented in good faith, but is intended only as aguide for student projects. Full structuralcalculations should be used in relation tobuilding projects.

The Studio Guide was written by ProfessorRaymond Ogden (SCI Professor in ArchitecturalTechnology at Oxford Brookes University), withcontributions from Professor Roger Plank ofSheffield University, and Dr Mark Lawson andJames Atree of the SCI.

Although care has been taken to ensure, to the best of ourknowledge, that all data and information contained herein areaccurate to the extent that they relate to either matters of fact oraccepted practice or matters of opinion at the time ofpublication, The Steel Construction Institute, the authors andthe reviewers assume no responsibility for any errors ormisinterpretations of such data and/or information or any lossor damage arising from or related to their use.

PRODUCTSHot rolled steel sections 4Light steel sections (cold formed sections) 5Fabricated light steel lattice trusses 5Fabricated beams 5Light steel cladding 6Light steel decking 6

FRAMING SCHEMATICS Composite beam 7Slimdek® 8Portal frame 9Trusses 10Space frames 10Long span structures 11Light steel frames 12Modular construction 13

CONNECTIONS Fin plate beam-to-column 14End plate beam-to-column 14Haunched beam-to-column 14End plate beam-to-beam 15Pinned tube connection 15Column base connection 15Quicon™ connection 16Steel to concrete 16

CLADDING SYSTEMSStrongback system 17Integral panels 18Stick system 19Brick 20Light steel cladding 21Bolted glazing system 22

FIRE PROTECTION 23

FURTHER READING 24

CONTENTS

4

3

2

1

STUDIO GUIDE 1

Lowry Centre, Manchester

Peckham Library

Wilkinson E

yre (Nick W

ood)

Gateshead Millennium Bridge

Nicolas G

rimshaw

Alsop A

rchitects Ltd

National Space Centre

5

6

Steel is synonymous with modern architecture.Throughout the twentieth century the material hasinspired architects and engineers, for it combinesstrength and efficiency with unparalleled opportunitiesfor sculptural expression. Today, in an era ofarchitectural pluralism, and of engineering innovation,steel plays a central role in many of the mostsophisticated and accomplished examples of modernbuilding design. Partly this is due to the strides thathave been made in metallurgy, structural analysis,fabrication and construction; but perhaps morefundamentally it is testament to the continuingcommitment and fascination of architects and engineerswith a material that offers outstanding designopportunities.

The key attribute of steel is its high strength to weightratio, which gives remarkable spanning and loadcarrying ability. Steel lends itself to prefabrication. Wholestructures can be created in a factory environment andthen constructed quickly on site. Steel buildings arehighly adaptable, in that frames can be modified andaltered. Costs are low, recycling simple and aestheticopportunities rich and varied. As designers, fabricatorsand constructors continually advance the boundaries ofsteel design, both technically and expressively, the roleas a core part of modern architecture seems assured.

Steel is basically iron and carbon, but its properties canbe enhanced and modified by the addition of otheralloying elements and by the manufacturing process. The material is then made into sections, plate, or sheet,

and these simple products used to produce structuresand building components.

Standard approaches have evolved for many types ofstructure, the most common of which are described inthe following Sections. They are not constraininghowever. Departures from norms are commonplace, forsteel lends itself to creative solutions. Modernarchitecture is rich with solutions that defy simplecategorisation.

The most widely used structural frames rely on hotrolled steel sections; the material has been heated andpassed as a billet through heavy rollers that graduallyreduce the cross-section whilst at the same timeincreasing length; the material flows to the requiredshape. Simple wide span column and beam frameswhere the structural members are arranged in a threedimensional matrix like the solutions on pages 8, andportal frames such as that on page 9 are mainly based onthese sections.

For larger spans, hot rolled sections and plate can befabricated to form particularly deep beams or otherstructural members such as those shown on page 11, andthe same technique can be used for geometricallycomplex members such as the roof beams on the RenaultCentre or the steel arch of Lehrter Bahnhof. Standardsections can also be curved after manufacture usingheavy bending equipment, or be converted to perforatedweb profiles using a variety of approaches, some ofwhich split the beam into two and then reweld it so thatits depth and spanning ability is much increased.

INTRODUCTION

2 STUDIO GUIDE

Steel Arch, Lehrter Bahnhof, Berlin

Von G

erkan Mary A

rchitects

Lighter steel sections can be formed by bending sheetsteel to C or Z sections. Normally this is done usingeither a press or folding machine for special sections, ora cold rolling line for standard sections. Cold formedlight steel sections generally have greater structuralcapacity than equivalent timber sections, with commonstructural profiles ranging from around 75 to 500 mmdeep. These are particularly suitable for close centreframes such as wall and floor panels, roof purlins thatsupport cladding, light portal frames, beams andcolumns (where spans and loads permit), and for lightlyloaded and non-structural applications such as supportto internal walls and partitions. Increasingly, thesesections are being used for whole buildings such ashouses, apartments, hotels and offices (page 12), and formodular buildings (page 13). Profiled cladding, floordecks and similar products are also produced by coldrolling.

Steel members can be joined using a wide variety oftechniques including welding and bolting (Page 14),and connection design is an important part of anystructural system. Connection arrangements can behighly standardised like the structures of which they arepart (pages 15 and 16) or unique such as the mastconnection for the Commonwealth Games Stadium(page 3). Often in expressed steelwork, connectionsbecome important architectural elements in their ownright.

This publication provides a simple overview of some ofthe basic constructional and structural concepts onwhich most buildings are founded, and also includesselected aspects of associated technologies such ascladding and fire protection.

The accompanying CD, aimed at architectural students,contains a concise structures course that can furtherinform the selection and development of structuralsolutions.

STUDIO GUIDE 3

Renault Building

Yorkon

Murray Grove (front elevation)

Curved beams at Helsinki Airport

Arup A

ssociates

Mast connection, Commonwealth Games Stadium, Manchester

Section Product Corus size range (mm)* Typical Uses

Universal Beams 1016 x 305 457 x 191 254 x 146 Beams(UB) 914 x 419 457 x 152 254 x 102

914 x 305 406 x 178 203 x 133838 x 292 406 x 140 203 x 102762 x 267 356 x 171 178 x 102686 x 284 356 x 127 152 x 89610 x 305 305 x 165 127 x 76610 x 229 305 x 127 533 x 210 305 x 102

Universal Columns 356 x 406 305 x 305 203 x 203 Columns(UC) 356 x 368 254 x 254 152 x 152

Parallel Flange Channels 430 x 100 260 x 75 180 x 90 Channels(PFC) 380 x 100 230 x 90 180 x 75 Edge beams

300 x 100 230 x 75 150 x 90 Secondary steelwork300 x 90 200 x 90 150 x 75260 x 90 200 x 75 125 x 65

100 x 50

Equal angles 200 x 200 120 x 120 90 x 90 Truss members150 x 150 100 x 100 Bracing ties

Secondary steelwork

Unequal angles 200 x 150 150 x 75 100 x 65 Truss members200 x 100 125 x 75 Bracing ties150 x 90 100 x 75 Secondary steelwork

Square Hollow Sections 400 x 400 160 x 160 80 x 80 Columns350 x 350 150 x 150 70 x 70 Trusses300 x 300 140 x 140 60 x 60250 x 250 120 x 120 50 x 50 Members subject 200 x 200 100 x 100 40 x 40 to torsion180 x 180 90 x 90

Rectangular Hollow Sections 500 x 300 200 x 150 100 x 60 Columns(RHS) 450 x 250 200 x 120 100 x 50 Beams

400 x 200 200 x 100 90 x 50 Trusses300 x 200 160 x 80 80 x 40300 x 100 150 x 100 60 x 40 Members subject250 x 150 120 x 80 50 x 30 to torsion250 x 100 120 x 60

Circular Hollow Sections 508 193.7 42.4 Columns(CHS) 457 168.3 26.9 Trusses

406.4 139.7355.6 114.3 Members subject323.9 88.9 to torsion273 76.1244.5 60.3 219.1 48.3

Asymmetric Beams 300 ASB (FE) 249 280 ASB (FE) 136 Slimdek® Floor BeamsASB 300 ASB 196 280 ASB 124

300 ASB (FE) 185 280 ASB 105300 ASB 155 280 ASB (FE) 100300 ASB (FE) 153 280 ASB 74

Hot rolled steel sections

4 STUDIO GUIDE

1 PRODUCTS

Most of these sections are available in a range of cross-sectional thicknesses (usually termed weights). Refer to Corus section tables.Structural Hollow Sections are also formed by cold rolling. These sections are not interchangeable with hot rolled Structural Hollow Sections as thesection properties are different.

Section designated (FE) can achieve 60 minutes fire resistance without fire protection. Slimdek® is a trade mark of Corus.

Section Product Common UK Size Range* Typical Uses

C Section 75 to 300 mm deep Lipped Structural frames JoistsStuds ColumnsUnlipped Connecting members in panels

Sigma 130 to 265 mm deep Sheeting rails PurlinsStudsJoists

Zed 140 to 300 mm deep Purlins Sheeting Rails

Section Product Type size range*

Cellular beam 457 to 915 mm deep1.5 times the depth of the section from which the twohalves of the beam are cut.

Castellated beam 457 to 915 mm deep1.5 times the depth of the section from which the twohalves of the beam are cut.

Plate girder Bridge construction, often more than 1m deep (usuallywithout openings)Tapered sections and sections with openings can be usedin buildings 400 to 1000 mm deep

Light steel sections (cold formed sections)

* Cold-formed sections are manufactured by many different companies and size ranges vary. For actual sizes refer to manufacturers’information. Summary information on sizes of channel sections is contained in Building Design using Cold Formed Steel Sections: An Architect’s Guide, published by The Steel Construction Institute. These sections are typically 1.2 to 3.2 mm thick and are galvanised.

* Fabricated structural sections are manufactured by many different companies and size ranges vary. For actual sizes refer to manufacturers’ information.

PRO D U CTS 1

Section Product Type size range* Typical uses

Lattice Trusses 220 to 3000 mm deep Floor beams Roof trusses- curved- pitched- parallel chord

STUDIO GUIDE 5

Fabricated light steel lattice trusses

Fabricated beams

Profile Product Typical proportions*

Re-entrant Depth 51 mmDistance between dovetail centres 152 mm

Trapezoid Depth 46 to 80 mmDistance between trough centres 225 to 300 mm

Deep Decking Depth 225 mmDistance between trough centres 600 mm

Profile Product Typical proportions*

Profiled Cladding Used in roofs and wallsDepth 30 to 60 mmWidth 900 to 1200 mm

Liner Sheets Used in built-up roofs with sheeting aboveDepth 10 to 30 mmWidth 900 to 1200 mm

Composite Panels Double skin panels with flat, ribbed or profiled external sheets. Various other materialsmay be used to provide the required insulationand strength characteristicsTypical thicknesses 35 to 100 mm

Standing Seam Roofing Permits relative movement of two roof panelsDepth 50 to 75 mmWidth 300 to 600 mm

Structural Liner Trays Used to span between rafters with roof sheeting overDepth 80 mmWidth 500 mm

Light steel cladding

Light steel decking (used for composite slabs)

6 STUDIO GUIDE

1 PRO D U CTS

*Cladding profiles are manufactured by many different companies and size ranges vary. For actual sizes refer to manufacturers information.

*Decking profiles are manufactured by many different companies and size ranges vary. For actual sizes refer to manufacturers information.

Approximate structural sizingPRIMARY BEAMSMaximum span 15 mFloor beam depth Span/20Roof beam depth Span/25

SECONDARY BEAMSMaximum span 12 mFloor beam depth Span/25Roof beam depth Span/30

Columns

FLOORS UC RHS1 152 x 152 150 x 1502-4 203 x 203 200 x 2005-8 254 x 254 250 x 2509-12 305 x 305 300 x 30013-40 356 x 406 400 x 400

F RAM I NG SCH E M AT ICS 2

STUDIO GUIDE 7

KEY1 Composite slab

(a) concrete(b) steel deck(c) reinforcement

2 Primary beam3 Secondary beam4 Shear studs5 Column

Composite beam

Primary and secondary beams incomposite steel frames are rigidlyconnected to the floor slab usingshear studs. This allows the floorslab, and the beams beneath, to actcompositely. Beam depths aretherefore less than in equivalentnon-composite frames.

Floor slabs generally compriseprofiled steel floor deck with in-situconcrete cast over the deck. The deck acts as permanentshuttering and spans in a directiontransverse to the secondary beams.

View perpendicular to span of floor deck View parallel to span of floor deck

1a

1c4

2

1b

1a

1c

4

2 or 3

1b

1a

1c

1

1b

2

5

34

FRAMING SCHEMATICS

Composite slab spans up to 3.6 m

2

Slimdek®

Slimdek® comprises an ASB steelsection contained within the depthof the slab. It supports deep profiledfloor decking. Ties runperpendicular to the beams.

The major advantage of Slimdek®

construction is that the beams arecontained within the floor depth.This reduces the overall height ofthe floor structure, and can improveservice integration.

Asymmetric beams (ASB) are hotrolled sections where the bottomflange is wider than the top flange.Spans of up to 9 m are possible.Some ASB sections have beenproportioned so that they canachieve up to 60 minutes fireresistance without applied fireprotection.

2 F RAM I NG SCH E M AT ICS

Detail

8 STUDIO GUIDE

1c

1a

2

4

3

2

1b

1a

1b

KEY1 Floor slab

(a) Concrete(b) Deep deck (c) Reinforcement

2 ASB3 Tie between frames4 Column

Slimdek® is a trademark of Corus.

Approximate structural sizingPRIMARY BEAMSMaximum span 9 mBeam depth Span/30

Columns

FLOORS UC SHS1 152 x 152 150 x 1502-4 203 x 203 200 x 2005-8 254 x 254 250 x 2509-12 305 x 305 300 x 300

Composite slab spans up to 9 m

KEY1 Profiled cladding2 Insulation3 Liner sheet4 Spacer5 Purlin6 Side rail7 Portal frame

(a) roof beam(b) column

Portal frameSteel portal frames are capable ofspanning large distances. They areused in the construction of factoriesand warehouses, and other low-risebuildings that require wide spans.Wall and roof bracing is normallyprovided in selected bays, often atthe end of buildings. Additionalvertical column or beam sectionsmay be introduced at the gables(wind posts) to support cladding onend walls.

Roof beams (rafters) and columnsare usually fabricated from hotrolled steel sections, while purlinsand cladding rails are usually inlight steel sections. Liner trays maybe used as an alternative to claddingrails.

Cladding materials include built-upcladding systems (as shown),composite cladding panels, andmasonry.

Typical light steel cladding details are provided in Section 4.

Small single storey industrialbuildings can also be constructedusing light steel sections for thecolumns and rafters

STUDIO GUIDE 9

1

1

2 3

6

7b

4

5

3

2

7a

PURLINS Maximum span 4.5 – 7.5 mPurlin depth Span/35

LINER SHEETSTypical maximum span 3 mLiner depth 20 mm

PROFILED CLADDINGTypical maximum span 3 mProfile depth 35 – 40 m

Approximate structural sizingROOF BEAMS (RAFTERS)Typical span 20-50 mBeam depth Span/60

COLUMNSColumn depth 1.25 x roof beamWidth as UB sections

F RAM I NG SCH E M AT ICS 2

Light steel rafters span up to 18 m

TrussesSteel trusses are highly efficientstructural forms, able to spanconsiderable distances. They arevisually light and services can passthrough them.

Trusses may be fabricated from avariety of steel sections including:circular, square and rectangularhollow sections, angles, flats, rodsand cold-formed profiles. Circularhollow sections are often used forexposed architectural steelwork,and specialist machinery has beendeveloped to cut the complex tube-to-tube connections that ariseat nodes where multiple tubesintersect. Columns are generallyUniversal Column sections (UCs),or Square or Circular HollowSections (RHS or CHS).

Trusses may have flat cross-sections (one chord normallyabove the other), triangular cross-sections, or occasionally mayhave rectangular cross-sections toaccommodate walkways orbuilding services.

The components (members) areusually fully welded, however longmembers can be fabricated inseveral sections. Trusses arenormally connected to columnsusing bolts. Where trusses areconnected to RHS or CHS sectionsand it is not possible to installconventional nuts onto the end ofbolts inside the section,conventional bolts may be used inspecially threaded holes.Alternatively, proprietary bolts maybe used that incorporate anexpanding sleeve.

Approximate structural sizing

ROOF BEAMSDepth Span/15Typical maximum length 60 m

FLOOR BEAMSDepth Span/12Typical maximum length 10 – 25 m

Space framesSpace frames are essentially threedimensional trusses able to span intwo directions. They may be flat foruse as roofs, walls or inclined walls,or may be curved to formcontinuous barrel type roofgeometries. Flat frames used asroofs sometimes have slightcambers to direct water toappropriate roof outlets. Space frames allow for easy servicedistribution within their depth andcan provide light elegant structuralsolutions.

SPACE FRAMESDepth Span/40Clear span 100 m

2 F RAM I NG SCH E M AT ICS

10 STUDIO GUIDE

1

2

3

3 3

1

1

2

1Pitched Truss

Flat Truss

3

Frank Gehry

Curved roof, Berlin

KEY1 Chord 2 Lattice 3 Column

Type:

Cellular beamsPerforations lighten sections and provide routes forbuilding services.

Long span structures

STUDIO GUIDE 11

Usual maximum span 15 mBeam depth Span/22

The merit of each of the above systems depends onspan, cost, degree of service integration, futureadaptability etc.

Haunched beamsRigid connections reduce overall beam depth.

Usual maximum span 18 mBeam depth Span/30

Fabricated beamsFabricated beams are usually used where long spansare required. The section is fabricated from threeplates welded together to form an I-section. It ispossible to design these sections with web openingsto allow for service integration.

Usual maximum span 15 mBeam depth Span/20

Composite trussesTrusses connected to floor slab using welded shearstuds. Trusses may use tee, angle or hollow sections.

Usual maximum span 30 mBeam depth Span/15

Stub girdersShort beam sections are welded to the top of beamsand support the floor slab. Services may passthrough voids.

Usual maximum span 20 mBeam depth Span/15

Tapered beamsTapered sections provide service zone adjacent tocolumns.

Usual maximum span 25 mBeam depth Span/20

These systems incorporate facility for integration of large building services.

F RAM I NG SCH E M AT ICS 2

Alternative tapered beam profiles:

Light steel framesLight steel construction uses cold-formed steel channel sections(C-sections) that are much thinner(typically 1.6 to 3.2 mm thick) thanhot rolled sections. Light steelsections are produced fromgalvanized steel. Sections normallyrange between 75 and 300 mm deep,and are available from variousmanufacturers.

Light steel frames normally combinemany different section sizes andincorporate steel floor joists, beams,columns, stud walls (load bearing)and partitions (non-load bearing).Connections are made using self-drilling, self-tapping screws,welds or bolts.The frame isassembled on site, usually from aseries of panels.

Acoustic and fire resistance criteriaare important in separating wallsand floors. Floor beams may beused in conjunction with compositeslabs. Open roof structures may becreated using attic type trusses orpurlins spanning between flankwalls.

FLOOR JOISTS (SINGLE C)Maximum span 5 mSpacing 450 or 600 mmJoist depth Span/25Thickness 1.6 – 2.4 mm

BEAMS (DOUBLE C)Maximum span 6 mBeam depth Span/18Thickness 2.4 – 3.2 mm

STUDS (SINGLE C, 2 STOREY BUILDING)Spacing 450 or 600 mmDepth 75 – 100 mmThickness 1.6 – 2.4 mm

COLUMNS (DOUBLE C, 3-STOREY BUILDING)Spacing 4 – 6 mDepth 150 – 250 mmThickness 2.4 – 3.2 mm

KEY1 Floor joist2 Stud 3 Bracing4 Curved rafter

12 STUDIO GUIDE

Approximate structural sizing

1

2

3

4

2 F RAM I NG SCH E M AT ICS

Modular construction, sometimescalled volumetric construction,allows buildings or substantialparts of buildings, to be constructedin a factory environment. Wall, floorand ceiling frames can bemanufactured efficiently using lightsteel sections. Wall frames typicallycomprise vertical steel studs withtop and bottom tracks, and eitherbracing or sheathing boards toprevent racking. Floor and wallcassettes comprise horizontal joistsconnected together at both of theirends with a channel or similarsection. Alternatively they may beconstructed in-situ from individualmembers.

Two types of module are commonlyused: modules with columns thattransfer forces as point loads, andmodules with load bearing wallsthat transfer vertical forces alongtheir length in a similar fashion toconventional load bearingconstruction.

The size of modules is usuallydetermined by transport and liftingcriteria. Hotel rooms, student study-bedrooms and bathrooms arenormally built as single modules,whilst larger spaces, such aspayment areas, shops at fillingstations and fast food restaurantsare generally constructed fromseveral open sided modulesinstalled side by side.

Other important applications ofmodular construction includeprefabricated plant rooms andtoilets.

Structural sizes are similar to thosegiven for light steel frames in theprevious section.

Hybrid modular constructioninvolves the use of modules withpanels or conventionallyconstructed building elements.Houses, for example, may beconstructed with modules for thoseareas that require complex fitting-out such as kitchens,bathrooms and staircases, whilst theremaining areas (sometimes termedbaggy space) are constructed usingpanels or built in-situ.

STUDIO GUIDE 13

Modular construction

Yorkon

Murray Grove (rear elevation)

Yorkon

Murray Grove under construction

F RAM I NG SCH E M AT ICS 2

Fin plate beam-to-column connectionFin plate connections are fabricated by welding a singleplate to the column. Beams are normally attached usingtwo or more bolts. Where necessary, adjustment can beprovided using slotted holes (for instance horizontallyslotted holes in the web of the section attached to the finplate).

End plate beam-to-column connectionEndplate connections have a single plate welded to theend of the beam, which is bolted to the column usingtwo or more bolts arranged in pairs. Where necessary, adjustment can be provided by slottedholes and shims between the endplate and the section towhich is attached.

When connections are made to hollow section columns,it is not possible to install conventional nuts onto theends of bolts inside the section. Specially threaded holesusing the ‘Flowdrill’* method or proprietary bolts thatincorporate an expanding sleeve may be used.

*’Flowdrill’ is a trademark of Flowdrill BV.

Haunched beam-to-column connectionHaunched connections are used where there is a need toachieve high moment transfer. The haunch locallyincreases the effective depth of the section. Beams areattached using multiple pairs of bolts through anendplate. Little adjustment is possible. Haunchedconnections are common in portal frames.

KEY1 Fin Plate welded to column2 Bolts3 Column4 Beam

KEY1 End plate welded to beam2 Bolts3 Column4 Beam

KEY1 Haunched beam end2 Bolts3 Endplate4 Column5 Beam

14 STUDIO GUIDE

1

1

1

1

1

1

1 2

2

2

2

2

2

4

4

3

3

3

3

3

3

4

4

4

4

5

5

4

3

CONNECTIONS3

End plate beam-to-beam connectionThe end plate beam-to-beam connection is similar to thebeam-to-column endplate connection. However becausethe top flanges of the beams support floors or roofstructure directly, the top flange at the end of theincoming beam has to be notched. An alternative detailis to provide a projecting welded bracket or fin-plate onthe supporting beam. Adjustment is similar to the beam-to-column detail.

Pinned tube connectionThe ends of tubes can be profiled and welded, or can bebolted using simple fin-plates. Single fin-plates may bewelded to each of the members or, where eccentricitiesneed to be minimised, a single finplate on one membermay be designed to locate between a pair of fin-plates onthe other (as shown). Attachment is normally madeusing either bolts or pins.

Column base connectionThere are a variety of ways of connecting columnbaseplates to concrete ground structures. One commonmethod involves casting bolts, via bolt pockets, into theconcrete. Bolts are able to move slightly within thepockets to provide horizontal adjustment of thebaseplate before grouting the gaps around the bolts.Vertical adjustment is by shims or packs insertedbetween the baseplate and the top surface of theconcrete.

KEY1 End plate welded to

supported beam2 Bolts3 Supported beam4 Supporting beam

KEY1 Fin-plate2 Bolt or pin3 Tubular section

KEY1 Bolt pockets cast in concrete2 Base-plate3 Column

11

2

2

3

3

3

3

4

3

1

1

2

4

3

3

3

1

1

STUDIO GUIDE 15

Arup A

ssociates

Mast base and pin, Commonwealth Games Stadium, Manchester

CON N ECT ION S 3

3 CON N ECT ION S

Quicon™ connectionThe Quicon™ connection uses a special connectorcomponent that eliminates the need for onsite bolting. Itcan be used for beam to column or beam to beamconnections. The supporting member, either a beam orcolumn, is fitted with a fabricated tee piece usingordinary structural bolts. The tee piece is fabricated withkey-hole shaped slots. The special connector is bolted tothe supported beam prior to erection.

Using this type of connection improves the speed oferection, which results in reduced construction costs.Safety on-site is also improved, as site operatives spendless time aloft and do not need to carry equipment withthem.

KEY1 Tee piece2 Connector bolts3 Special connectors4 Column5 Supported beam

KEY1 Steel beam2 Concrete wall3 Bracket welded to beam4 Reinforcement bracket clamp*5 Connecting rod6 Shims on grout bed7 Shear connector*8 Local additional reinforcement

*Option, do not omit both 4&7

16 STUDIO GUIDE

Steel-to-concrete connectionMany building and refurbishment projects requirestructural connections between steelwork and concreteconstruction. For example, a multi-storey building witha steel frame may rely on a concrete core for stability;this requires fixings to be made between the steelworkand the concrete.

For new construction, connections are usually madeusing a steel bracket, which can be cast into the concreteelement prior to erection of the steelwork. Care shouldbe taken to ensure that the connection can be madequickly and safely during erection and sufficientadjustment is provided to meet erection tolerances.

In refurbishment work, connections to existing concretestructures can present particular difficulties. Post-drilledexpanding anchors or resin anchors are commonly used,but these must be positioned so that they do not clashwith reinforcing bars. This may mean that slotted holesare required in the fixing bracket or the fixing bracketmust be fabricated after suitable locations for the postdrill anchors are determining on site.

4

4

3

1

1

6

7

35

6

2

7

5

8

Beam to Column

Beam to Beam

KEY1 Tee piece2 Connector bolts3 Special connectors4 Supporting beam5 Supported beam

1 Tee piece2 Connector bolts

21

1 Keyhole slot2 Special connector

21

Special ConnectorFabricated Tee Piece

3

12

3

2

5

1

4

54

Strongback systemStrongback cladding systems have a sub-frame thatsupports thin cladding panels. Units are normallystorey height and up to 6 – 9 m wide. They are fixedeither to the edge of the floor slab or to the floor edgebeams or to columns. The supporting frame is usuallyconstructed from either hot rolled or light steelsections. Cladding materials include stone, coated steeland stainless steel.

Panels are normally fixed to the building at four points(two points at the top of the panel and two at thebottom). They may be either hung from the topconnections or may bear on the bottom connections.Connections carrying the self-weight of the panel aretermed structural. Other connections act as windrestraints and prevent swaying, or overturning of thepanel, depending upon whether the panel is top hungor bottom supported. Provision is made at the fixingsfor building movements and tolerances.

Since panels can be relatively large, it is possible to cladbuildings rapidly by using storey-high units.

KEY1 Strongback2 Cladding3 Connection to building

a) Structural connectionb) Wind restraint

4 Floor slab5 Edge beam

Detail (bottom supported panel)

1 2

3b

3a

3b

3a

1

5

4

5

4

2

STUDIO GUIDE 17

CLADDING SCHEMATICS4

Integral panelsIntegral cladding panels are generally made fromconcrete, and are able to support their own weight andresist wind loads without additional framing. As a resultthey tend to be heavier than strongback panels (typicallyaround 300kg/m2). Panels are normally storey heightand between 3 and 9 m wide.

They may be clad in other materials such as stone orceramic tiling. Panels may be top hung or bottomsupported and, like strongback panels, are normallyfixed to the building at four points (two points at the topof the panel and two at the bottom). Panels typicallybear on the slab edge using ‘boots’ (projecting concretenibs) or bolted-on brackets.

Two structural connections are normally made at thepoints of bearing, with two wind restraint connections atthe opposite edge (refer to strongback description fordefinitions). Bolted on brackets take up less, spacewhich is particularly advantageous in buildings withoutraised floors where boots can be difficult toaccommodate.

4 CL ADDI NG SCH E M AT ICS

18 STUDIO GUIDE

Detail (top hung panel)

2a

4

1

3

2b

KEY1 Panel2 Connection to building

a) Structural connectionb) Wind restraint

3 Floor slab4 Edge beam

2b

3

4

2b

1

2a

2a

Stick systemStick cladding systems comprise a series of verticalmembers (mullions) and horizontal members (transoms)that form a grid. This grid is used to restrain either solidpanels or glass using rubber gaskets, and is normallyfixed to the floor edges by specially designed brackets,which provide wind restraint (refer strongbackdescription for definitions). The self-weight of thecladding is normally taken to the ground through themullions.

Stick systems are amongst the lightest forms of cladding(typically 50 kg/m2). Mullion spacings are normally inthe range 1.2 – 2 m, although wider spacings arepossible. Transom spacings are normally determined bypanel requirements and the architectural treatment of thefaçade.

Stick systems can be ‘unitised’ whereby horizontal andvertical members are prefabricated into units, which arecraned onto the façade. Special edge members havebeen developed for these systems.

STUDIO GUIDE 19

KEY1 Glazed panel2 Mullion3 Transom4 Fixing bracket5 Floor slab6 Edge beam

3

2

5

4

5

62

1

Detail (Top hung panel)

Rautaruukki O

yj

Kone Building

CL ADDI NG SCH E M AT ICS 4

BrickMulti-storey frames may be clad in brickwork or stoneusing a range of proprietary systems based on speciallydesigned brackets and restraint devices.

The most common method of attaching brickwork tosteel frames is by the use of shelf angles fitted either tothe slab edge, or to plates welded onto the edge beams.The shelf angles are usually made from stainless steel.The method of attachment of the shelf angle allows forvertical adjustment to suit the brick coursing. Brickworkis constructed on these shelf angles and attached to thecolumns and to inner concrete block walls using brickties. Windposts are sometimes incorporated to giveimproved stability, particularly in tall buildings subjectto high wind pressures, or where large size panels areused. An expansion joint is used at the top of the panelsto take up relative movements between the buildingframe and the brickwork.

20 STUDIO GUIDE

KEY1 External brickwork2 Internal brickwork3 Shelf angle4 Windpost5 Column6 Edge beam7 Floor slab

1

1

4

1

2

3

4

5

3

6

2

6

7

4 CL ADDI NG SCH E M AT ICS

CL ADDI NG SCH E M AT ICS 4

Light steel cladding

Built-up system with liner sheetThese systems comprise two separate cladding sheets:an external sheet, which is coloured and highlyprofiled, and a more lightly profiled inner liner sheet.The sheets are separated by spacer rails and insulation.The liner sheet and spacers are fixed to cladding railsthat span between columns. The external sheet is fixedto the spacer. The normal method of attachment is byself-drilling, self-tapping screws.

Built-up system with liner traysLiner trays span between columns and replace the linersheet, cladding rails and spacer rails. Insulation is setwithin the liner trays and the external cladding sheet isfixed directly onto the outer flanges of the tray.

Composite panel systemComposite panels have a sandwich constructioncomprising two steel sheets bonded either side of aninsulating core of foam, mineral fibre or similarmaterial. The bonded panel produces good stiffness,and both profiled and smooth surfaces are available.Panels may be fixed using a variety of techniquesincluding self-drilling, self-tapping screws, and secret-fixing brackets located within the panel joints.

STUDIO GUIDE 21

The use of sophisticated bolted glazing systems, whereglass panels are attached directly to structural steelworkwithout using any intermediate framing, has grownsignificantly in recent years. Bolts attach the glass tobrackets on the steel through pre-drilled holes in theglass panes. The bolts provide point support instead ofthe continuous edge support given by conventionalframes.

Vertical glazing panels, up to 2 m x 2 m, can generally besupported using four corner fixings, whilst larger panels,up to 2 m x 4 m, typically require 6 fixings. Horizontaland inclined glazing may require more frequentsupports.

Various types of bolted fixing have been developed.These include simple bolts, where the head is proud ofthe surface of the glass, and countersunk designs that arerecessed into the glass. Articulated fixings are often usedin conjunction with large panes on tall or long span, steelstructures. As the glass panels and the supportingstructure bend under the combined effects of self weightand applied loads, articulated bolts allow some rotationof the fixing.

22 STUDIO GUIDE

Bolted glazing systems

Glazed entrance hall, NatWest Tower, London

Architect: E

. Norten

Structural Engineer: M

. Eekout/O

ctatube Space Structures.

Adjustment

Shims

Serratedfaces forverticaladjustment

Adjustment

Buro H

appold

Spider fixing detail

4 CL ADDI NG SCH E M AT ICS

Moda in Casa, Mexico City

There are four common methods offire protecting structural steelwork;intumescent coatings, board basedsystems, sprayed materials andconcrete encasement or filling.

Intumescent CoatingsIntumescent coatings may be brushedor sprayed onto steelwork rather likepaint. The materials expand whensubjected to fire and form aninsulating foam. Intumescentcoatings can achieve up to 120 minutes fire resistance, and areused mostly on exposed steelwork.

Board SystemsBoard based systems are used to formrectangular encasements around steelmembers, such as internal beams andcolumns. Paint or other finishes canbe applied directly to the boards. The level of fire resistance achieveddepends on the type and thethicknesses of the boards used and onthe method of attachment.

Sprayed MaterialsSprayed fire protection systems areusually based on cementitiousmaterials and are applied directlyonto the surface of steelwork. Theyare generally low cost, but cannotreceive finishes owing to their coarseuneven texture. Sprayed materialstend to be used where steelwork isconcealed or where appearance isunimportant. Fire resistance issimilar to that of board basedmaterials.

Concrete Filled Structural HollowSectionsStructural Hollow Sections (SHS) canbe fire protected by filling withreinforced concrete. Concrete filledstructural hollow sections can achieve120 minutes fire resistance.

Slimdek®

The Slimdek® system has inherent fireresistance as the ASB section isencased in concrete with only thebottom flange exposed to fire.Without fire protection Slimdek® canachieve 60 minutes fire resistance.

Periods of fire resistance in excess of120 minutes can be achieved if thebottom flange is fire protected.

Multi-storey frames requiring 30-60minutes can have 40% of the floorbeams unprotected by following therecommendations of a special designguide.

Protection thicknessesThe section factor of a particular steelsection is its surface area per unitlength divided by its volume per unitlength (A/V). This parameter defineshow quickly a steel section will heatup when subjected to fire. The sectionfactor for a member with boxprotection is lower than that for amember with profile protection, andhence box protected steelwork heatsup more slowly and requires lessprotection.

Typical spray or board thicknesses fora column in a multi-storey buildingare as set out in Table 1, below.

Table 1: Typical spray or board thicknessesbased on 254UC x 89 kg/m column in amulti-storey building.

Fire Profile Box resistance protection protection(minutes) (mm) (mm)

30 10 1260 18 1590 24 20120 30 25

Intumescent coatings

Board based system

Sprayed materials

Concrete filling

STUDIO GUIDE 23

FIRE PROTECTION5

Cladding

Colorcoat in buildings: A guide to architectural practice. British Steel Strip Products, 1990

OGDEN R G Interfaces: Curtain wall connections to steelframes. SCI P101, 1992

GORGOLEWSKI M T The design of twin-skin metalcladding. How to meet the new requirements of Part L of theBuilding Regulations. SCI P311, 2002

GORGOLEWSKI M T Metal cladding: U-valuecalculations. Assessing thermal performance of built-up metalroof and wall cladding systems using rail and bracket spacers.SCI P312, 2002.

Composite Construction

LAWSON R M Design for openings in the webs ofcomposite beams. SCI P068, 1987

OWENS G W Design of fabricated composite beams inbuildings. SCI P059, 1989

COUCHMAN G H et al. Composite slabs and beams usingsteel decking: Best practice for design and construction. SCI P300, 2000

Light Steel

LAWSON R M et al. Building design using cold formedsteel sections: Structural design to BS 5950-5: 1998.SCI P276, 2002

CLOUGH R H and OGDEN R G Building design usingcold formed steel sections: Acoustic insulation. SCI P128, 1993

LAWSON R M Building design using cold formed steelsections: Fire protection. SCI P129, 1993

The Steel Construction Institute Case studies on light steelframing – First series. SCI P176A, 1997

The Steel Construction Institute Case studies on light steelframing – Second series. SCI P176B, 2000

LAWSON R M et al. Modular construction using light steelframing: An architect’s guide. SCI P272, 1999

GORGOLEWSKI M T et al. Building design using coldformed steel sections: Light steel framing in residentialconstruction. SCI P301, 2001

Long Span Structures

LAWSON R M and RACKHAM J W Design of haunchedcomposite beams in buildings. SCI P060, 1989

NEAL S and JOHNSON R Design of composite trusses. SCI P083, 1992

BRETT P and RUSHTON J Parallel beam approach – A design guide. SCI P074, 1991

MacDERMOTT-SMITH M Design in steel 1 – The parallelbeam approach. British Steel Sections

LAWSON R M and McCONNEL R Design of stubgirders. SCI P118, 1992

Slimflor

MULLETT D M and LAWSON R M Slim floorconstruction using deep decking. SCI P127, 1993

MULLETT D M Slim floor design and construction. SCI P110, 1992

Corus Construction Centre Slimdek manual. Corus UK Ltd, 2001

McKENNA P D and LAWSON R M Service integrationin Slimdek. SCI P273, 2000

LAWSON R M et al. Design of asymetric Slimflor beamsusing deep decking. SCI P175, 1997

Fire

Fire resistant design of structural steelwork: Informationsheets. Corus Group

Fire protection for structural steel in buildings. Associationfor Specialist Fire Protection, Steel Construction Instituteand Fire Test Study Group, 3rd Edition – 2002

LAWSON R M and NEWMAN G M Fire resistant designof steel structures – A handbook to BS 5950 Part 8. SCI P080, 1990

HAM S J et al. Structural fire safety: A handbook forarchitects and engineers. SCI P197, 1999

NEWMAN G M et al. Design of steel framed buildingswithout applied fire protection. SCI P186, 1999

NEWMAN G M et al. Fire safe design: A new approach tomulti storey steel framed buildings. SCI P288, 2000

24 STUDIO GUIDE

FURTHER READING6

Design and production: www.greenandtempest.co.uk

6000-2/03

ISBN 1 85942 138 5

Publication Number SCI P167

© The Steel Construction Institute 2003