cisc architecturally exposed structural steel

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011CISC’s new AESS docs:

The little matrix that could

OAA Convention – Toronto, Ontario, 19 May 2011

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011The New CISC Architecturally Exposed

Structural Steel Documents

Sylvie BoulangerCanadian Institute of Steel Construction

Terri Meyer BoakeUniversity of Waterloo

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011What is AESS?

• Architecturally Exposed Structural Steel is steel that has been purposefully left exposed

• It is normally part of the Architectural aesthetic of the space

• It usually requires detailing, finish and handling that requires more attention and care than regular structural steel

• It adds to the cost of the contract

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011Where did AESS come from?

• Early iron structures were typically left ‘exposed’

• Much exposed iron (cast or wrought) could be found in bridges

• Architectural uses were associated with highly glazed structures

• Part of structural rationalist design of the mid 1800s

• Key in High Tech architecture of the 70s

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011Structural Rationalism

Connections were “enhanced” to add to the overall texture and aesthetic to make it more in keeping with traditional architecture of the period.

Biblioteque Nationale, Paris: Henri Labrouste

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STRUCTURALLYEXPOSED STEEL BRIDGES

The Iron BridgeCoalbrookdaleUK

1779

Engineering

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011Portman Bridge, Vancouver

Later bridges were simplified to reflect “load paths” – “decoration” lost

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011

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011Amgen Helix Bridge Engineering or Architecture?

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011Architecture wanted more!

Foster, Sainsbury Centre, 1977

The High Tech Movement

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011Contemporary AESS

Chicago O’Hare was the first AESS Airport

Detailing and workmanship expectations rose.

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011BCE Place,Toronto - CalatravaAND ROSE!!!

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011How good is “Good Enough”?

• AESS was being used on very high profile projects

• AESS was also being specified for mid to lower end projects

• Not all projects had/have the budget to pay for the sort of detailing of “A Calatrava”

• There was no agreed language or specification that could assist in the communication of expectations between the Architect, Engineer and Fabricator

Wisconsin Art Museum, Calatrava

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011Problems Specifying AESS

• In spite of the increasing use of AESS the only steel spec in existence was for standard structural steel

• Miscellaneous Metals did not address the structural requirements of AESS

• AESS could be priced out of sight on projects if excessive requirements were added “out of ignorance”

• All AESS did not need to be equally crafted…• Not to say that it should not be properly crafted, but

not all situations or projects either needed or could afford the same level of detailing

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“God is in the details”

What are they doing?

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They are grinding the surfaces …

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... for a structure that willbe visible close-up, but for passengers that are just standing by, waiting for an airport taxi.

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Baltimore Washington International Airport

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The welded connections on this truss are basic, not particularly refined.

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011Why?

Because it doesn’t matter, given the thickness of the coating …

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… and the distance.

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Dallas Opryland

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Pretty smooth welded connections!

A steel fabricator’s main office!

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011A reaction to the AISC documents of 2003

CISC felt the need to create a tiered/differentiated system to prevent the “over specification” of finish quality.

Unnecessary high standards in finishes could put projects out of reasonable price range.

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011AESS Questions

• When?– It all started with ....

• Why?– To improve communication

• How?– Initiatives, committee, roundtables

• What?– Category Matrix / A Spec, a Code, a Guide

• Who?– Architect | Engineer | Fabricator

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To findcommonground

Why?

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I want nice connections!

Architect

architect engineer fabricator

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011AESS Custody Battle!

Exposed steel is “owned” by the Architect, the Engineer and by the Fabricator! Success requires cooperation.

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011AESS: Factors of influence

• Distance. Visibility.• Connections mostly

bolted or welded• Tolerances required at

fabrication and erection

• Interior or exterior setting

• Paint finish, corrosion resistance, fire protection

• Access to detail to perform required finish

• Degree of expression• Size and shape of

structural elements

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structural elementsFORM

FINISH

FIT

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011The importance of form …

Vision realised

Tortured landscape

Canadian War Museum, Ottawa

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Ram’s Horn SculptureCalgary

Wind mitigation device!

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Montreal airport

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011How?

• Initiatives– AISC Guide (2003)– Ontario early doc (2003)– Quebec involvment (2004)– National interest (2005)

• National committee– A President, a Secretary,

Fabricators from every region, Regional staff, Guests

• Roundtables– Montreal– Toronto– Vancouver

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011National committee agreed that …

• Not all AESS need be created equal.– Adopted the “Category Approach”

• Distance should play a factor.– 6 m (20 ft) rule

• Finish would play a factor.– finish OF the steel surface– finish ON the steel surface

• Connection types are important differentiators.– bolted vs welded

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Zurich airport

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Telus Atrium, BC

The new documents refer to new sections like elliptical tubes

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Mountain Equipment CoopMontreal

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Le Café des Éclusiers

Le Café des ÉclusiersVieux Port de Montréal

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011Not all AESS need be created equal.

Bankers Hall Sculpture, Calgary

University of Guelph, Science Building

Exhibition Conference Center

Ricoh Center, Arena

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011Exquisite/expensive detailing

Needs to be close enough to be seen, and even touched, to be warranted

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011Distance should play a factor

AESS Structure of CIBC Concourse Skylight

Can anyone really see this?

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011Distance should play a factor

Edmonton City Hall, Alberta

MUST this be filled?

MUST this be realigned?

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011Distance should play a factor (360o)

CDP, Montreal

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011Coating, protection system should play a factor

Hi-gloss

Medium gloss

Thicker intumescent

Thick intumescent

Galvanized

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011Connection types are important differentiators

Canadian War Museum, Ottawa Waiward Steel Offices, Edmonton

BCE Place, Toronto

Bankers Hall, Calgary

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011Bolts vs Welds

The choice is there….

And the AESS is very different…

Palais des Congrès de Montréal

Lougheed Skytrain Station, Vancouver

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011Round Tables made us realise that …

• The Category Matrix was a winner.• The Sample Spec should be part of the Structural

Steel Division (not a separate one).• The Sample Spec should be part of the Engineer’s

spec, NOT the Architect’s!• Approximate cost premiums should be provided as a

very rough guideline.• These documents should provide a means for good

communication between the Architect, Engineer and Fabricator/Detailer/Erector.

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011What?

Subdivision of Specification for Structural Steel

Appendix I of the CISC Code of Standard Practice

CISC Guide for specifying AESS

Category Matrix

740 Bel-Air, Montreal

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structural elements

SPEC+

CODE

GUIDE

GUIDE

MATRIX

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011Approximating Cost Premiums

• Discussions/roundtables made it apparent that Architects and Engineers wanted cost premiums provided

• Cost premiums could begin to differentiate the AESS Categories

• Fabricators wanted no part of having them included• As a compromise a “range” of extra cost has been

included• The range is very wide and should only be used as a

starting point for contractual discussions between the Architect, Engineer, Fabricator and Client

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Categories go from lowest at the right to highest at the left.

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Viewing distance is noted as the differentiating factor between the high and low end AESS Categories.

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Characteristics are listed from the most common/least expensive at the top to the more specialized at the bottom.

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Estimated cost premiums over Standard Structural Steel are noted at the bottom.

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Roof trussesfor arenas, retailwarehouses,canopiesCost premium: Low(20-60%)

AESS 1

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011AESS 1 – Basic Elements

Semiahmoo Library, Surrey, B.C.

Ricoh Center, Arena

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0111.1 Surface preparation to SSPC-SP 6

photo: Dry-Tec website - www.drytec.ca

AESS 1

SP 15

SP 3 : Power Tool Cleaning

SSPC-SP 6 for complete removalof visible oil, mill scale, rust, paint.

SP 6 : Commercial Blast Cleaning

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0111.1 Surface preparation to SSPC-SP 6

Dry-Tec

AESS 1

Shot blast cleaning with the use of abrasives

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0111.2 Sharp edges ground smooth

photo: AISC AESS Guide

AESS 1

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0111.3 Continuous weld appearance

AESS 1

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011Not to cover welds

AESS 1

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TC Bolts

Hex bolts by default

The side on which the bolt heads should appear can be specified …. not the rotation!

1.4 Standard structural bolts

AESS 1

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TC Bolts


AESS 1

Court 1, Jarry Park, Montreal

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TC Bolts

Or TC bolts


AESS 1

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TC Bolts

Weld spatter prevents a quality/smooth finish as the imperfections will translate through the coatings.

1.5 Remove weld spatter

AESS 1

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Retail and arch. bldgs viewed ata distanceCost premium: Low to Moderate(40-100%)

AESS 2

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011AESS 2 – Feature Elements (>6m)

Les Ailes, Montreal Dorval Airport, Montreal

National Works Yard, Vancouver

Lillis Business School, Oregon

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AESS 2

2.1 Visual Samples (optional)

1. 3-D rendering;2. Physical sample of surface preparation and welds;3. First off inspection; First element fabricated for use

in finished structure 4. Mockups; Scaled or full-scale. Mockups are to

demonstrate aesthetic effects as well as qualities of materials and execution:a. May have finished surface b. Architect’s approval of mockups required;c. Retained until project is completed; d. Approved full-scale mockups may be part of work.

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0113-D rendering

• Ottawa airport

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011First off inspection at Toronto Airport

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011Approved first off inspection assembly

One of the “wishbones” is the full scale first off inspected assembly. Can you tell which one?

Pearson International Airport, Toronto

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AESS 2

2.2 One-half standard fabrication tolerances

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AESS 2

2.3 Fabrication marks not apparent

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AESS 2

2.4 Welds uniform and smoothZurich airport

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0112.4 Welds uniform and smooth

Brown Center, Baltimore, MD.

Cannon Street, London

National Works Yard, Vancouver

3 very different welded conditions, yet all are appropriate to the project

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Airports, shoppingcentres, hospitals, lobbiesCost premium: Moderate(60-150%)

AESS 3

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011AESS 3 – Feature Elements (<6m)

Edmonton International Airport OHare International Airport

Ottawa International Airport

Palais des Congrès de Montréal

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3.1 Mill marks removed

AESS 3

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0113.1 Mill marks removed

AESS 3

Example of mill mark show through.

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0113.2 Butt and plug welds ground smooth and filled

Right side shows groove weld ground smooth.photo: AISC AESS Guide

AESS 3

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011Plug welds ground smooth and filled if visible

Niagara Casino

AESS 3

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0113.3 HSS weld seam oriented for reduced visibility

AESS 3

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0113.4 Cross sectional abutting surface aligned

3.5 Joint gap tolerances minimized

AESS 3


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0113.5 Joint gap tolerances minimised

Lake City Way Skytrain Station, Vancouver

Regan International Airport, Washington, DC

Pritzker Pavilion, Chicago

Required to accommodate complexity and alignment

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0113.5 Joint gap tolerances minimised

Regan International Airport, Washington, DC

Pritzker Pavilion, Chicago

Required to accommodate complexity and alignment

Art Gallery of Alberta, Edmonton

AESS 3

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3.6 All welded connections (optional)

AESS 3

Requires skilled field welder.

Millennium Park, Chicago

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AESS 3

Discrete bolts can be proposed as unobtrusive.

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AESS 3

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011Unobtrusive connections

Even where design governs, there are alternates to field welding

Seattle Public Library

AESS 3

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011Hidden connections

Where site welding might be problematic, make parties aware that bolted connections may be effectively “hidden”

Media Tower, Dundas Square, Toronto

AESS 3

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011

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011Hidden connections

This hidden connection must also be weatherproof

Media Tower, Dundas Square, Toronto

AESS 3

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Showcase or dominantelements, sculpturesCost premium: High(150-250%)

AESS 4

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011AESS 4 - Showcase or dominant elements

BCE Place, TorontoCDP, Montreal

Wells Fargo Bridge, Salt Lake City

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0114.1 HSS seam not apparent

AESS 4

CDP Building, Montreal

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0114.2 Welds contoured and blended

Very expensivephoto: AISC AESS Guide

AESS 4

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0114.3 Surfaces filled and sanded

AESS 4

Niagara CasinoSt-Pierre Passage, Montreal

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0114.3 Surfaces filled and sanded

AESS 4

Rose Center New York City Polshek

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0114.4 Weld show-through minimized


AESS 4

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This section is for those who have unusual requirements or are confident enough to create their own set of requirements

AESS C

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011Status of the New AESS Documents

• Completed and available for download at www.cisc-icca.ca/aess are:– Matrix– Sample Spec– Code of Standard Practice– References– AESS Guide

http://www.cisc-icca.ca/aess

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011Re-used / Sustainable Steel

• An increasing number of projects are making use of re-used steel to be sustainable

• Some of these projects choose to leave the steel exposed to “celebrate” its re-use

• A Custom spec will be required for such projects as the demounting, transportation, re-erection of the steel will be unique and vary by project

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011Angus Technopole

• Project used an old steam locomotive shed

• Repurposed for offices and a grocery store

• Most of the steel was left in its original condition to show off the reuse

• Other was “cleaned up and repainted, leaving the original rivets exposed.

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Rivets

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011Tohu

Steel beams saved from demolition at the Port of Montreal were reused to support the roof.

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011Re-used steel properties

1. Do you have the old mill certificate?

2. Have you tried to check the steel as “unidentified steel”?

• If yes to either question, proceed to re-use.• If not, perform test for physical and/or

chemical properties. Cost: 500-1000$/test

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011University of

EdmontonTriffo Hall

111

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The 740 Bel-Air : LEED Gold

Joists from previous buildingwere dismantled, storedand reused.

Consortium: ABCP, BeauchampBourbeau, Busby & Assoc.

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011The AESS Guide:

• The illustrated Guide to assist Architects and Engineers in understanding the new specification documents is nearing completion

• This part of the presentation will walk you through the COMPLETED version of the Guide!

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This illustrated guide is designed as a supplement to the new set of AESS Specification Documents created by the CISC National Committee over the period of 2005 to the present time.

So let’s take a walk through the Guide!

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An Elaboration of the Spec and text based documents

Additional value added detailing and decision making information

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Additional value added detailing and decision making information

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The Development of the new AESS Documents Focussed on translating the

PRIMARY FACTORS OF INFLUENCE

Into specifications and codes that could be easily used and incorporated into practice.

~ Distance and Visibility

(if you could not see it up close or touch it, finish

requirements could be softened)

~ Connections mostly bolted or welded

(different aesthetics requiring differing levels of finish)

~ Tolerances required at fabrication and erection

(different as a function of scope and complexity)

~ Access to detail to perform required finish

(greater concern for workmanship may mean altering the

detail or its location to allow access for different types of

tools)

~ Degree of expression

(complexity of structure and connections)

~ Size and shape of structural elements

(W sections and HSS have different detailing requirements

and their use infers a different approach to detailing and

finish)

~ Interior or exterior setting

(weathering issues, need to fire protect, potential for impact

damage)

~ Paint finish, corrosion resistance, fire protection

(depending on the relative thickness of the finish material,

more or less care may be required when preparing the

surface, edges and welding of the steel

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The core idea!FORM, FIT & FINISH

Two “TREES” – both AESS – each quite different from the other – so why would the AESS Specification be even remotely the same????

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011The generation of the overall

approach to the new set of CISC AESS Documents is based upon the key idea of the Category “Matrix”

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THE CATEGORY APPROACH

VIEWING DISTANCE

TYPE OR FUNCTION OF THE BUILDING

RANGE OF COST INCREASE

ALL AESS IS BENCHMARKED AGAINST PRACTICES FOR STANDARD STRUCTURAL STEEL

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AESS1 – BASIC ELEMENTS

is the first step above

Standard Structural Steel.

This type of application would

be suitable for “basic”

elements, which require

enhanced workmanship. This

type of exposed structure

could be found in roof trusses

for arenas, warehouses and

canopies and should only

require a low cost premium in

the range of 20% to 60% due

to its relatively large viewing

distance as well as the lower

profile nature of the

architectural spaces in which it

is used.

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Roof trussesfor arenas, retailwarehouses,canopiesCost premium: Low(20-60%)

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AESS 2 – FEATURE ELEMENTS

includes structure that is

intended to be viewed at a

Distance > 6 m. It is suitable for

“feature” elements that will be

viewed at a distance greater than

six meters. The process requires

basically good fabrication

practices with enhanced

treatment of weld, connection

and fabrication detail, tolerances

for gaps, and copes. This type of

AESS might be found in retail and

architectural applications where

a low to moderate cost premium

in the range of 40% to 100% over

the cost of Standard Structural

Steel would be expected.

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Retail and arch. bldgs viewed ata distanceCost premium: Low to Moderate(40-100%)

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Includes structures that will be

viewed at a distance ≤ 6 m.

The Category would be

suitable for “feature” elements

– where the designer is

comfortable allowing the

viewer to see the art of

metalworking. The welds

should be generally smooth

but visible and some grind

marks would be acceptable.

Tolerances must be tighter

than normal standards.


As this structure is normally viewed closer than six meters it might also frequently be subject to touch by

the public, therefore warranting a smoother and more uniform finish and appearance. This type of

structure could be found in airports, shopping centres, hospitals or lobbies and could be expected to incur

a moderate cost premium that could range from 60% to 150% over Standard Structural Steel.

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Airports, shoppingcentres, hospitals, lobbiesCost premium: Moderate(60-150%)

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AESS 4 – SHOWCASE ELEMENTS

or “dominant” elements is used

where the designer intends that

the form is the only feature

showing in an element. All welds

are ground and filled edges are

ground square and true. All

surfaces are sanded and filled.

Tolerances of these fabricated

forms are more stringent,

generally to half of standard

tolerance for structural steel. All

of the surfaces would be “glove”

smooth. The cost premium of

these elements would be high

and could range from 100% to

250% over the cost of Standard

Structural Steel – completely as a

function of the nature of the

details, complexity of

construction and selected finish.

Brookfield Place

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Showcase or dominantelements, sculpturesCost premium: High(150-250%)

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AESS C – CUSTOM ELEMENTS

was created to allow for a completely

custom selection of any of the

Characteristics or attributes that were

used to define the other Categories. It

would allow complete flexibility in the

design of the steel, but would therefore

require a high level of communication

amongst the Architect, Engineer and

Fabricator. The premium for this type of

AESS could range from 20% to 250%

over regular steel. A wide range may

seem odd for “custom” elements, but the

lower bound of this Category also

includes specialty reused steel for

sustainable purposes, and steel that

might be purposefully less refined in its

Characteristics.

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011Bow Encana

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011Canadian Museum for Human Rights

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THE CHARACTERISTICS OF THE MATRIX

AESS 1 – BASIC ELEMENTS

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AESS C – CUSTOM ELEMENTS

WORKING OUTSIDE OF CANADA

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011WORKING OUTSIDE OF CANADA

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011WORKING OUTSIDE OF CANADA

There even are limits on the kind of workmanship that can be expected for the likes of Herzog and de Meuron and Arup on high profile projects such as the Birds Nest!

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011Beijing International Airport

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What about cleaning and maintenance?

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COATINGS – GENERAL ISSUES

SURFACE PREPARATION

THIS PORTION OF THE GUIDE IS A MAJOR VALUE ADDED PIECE OVER AND ABOVE AN ELABORATION OF THE CHARACTERISTICS OF THE MATRIX AND IS INTENDED TO HELP ARCHITECTS AND ENGINEERS TO UNDERSTAND THE FINE POINTS OF SELECTING THE CATEGORY AS A FUNCTION OF THE “FINISH”.

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EXTERIOR VS INTERIOR FINISHES

PAINT SYSTEMS

• Water, snow and weathering are obvious issues here. Steel must be detailed so that moisture does not get trapped inside, causing the structure to rust out.

• Some details create ledges that will trap snow and meltwater.

• Some arrangements will also collect dirt and provide roosts for pigeons.

• The paint type and finish MUST be known.

• The level of gloss will either mask or reveal minute imperfections.

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SHOP VS SITE PAINTING

PRIMERS

INTUMESCENT COATINGS

• Quality is better with shop painting• Shop painting is less costly• Shop painted steel requires better care and handling

during transportation, site staging and erection• Anticipate that some touch up work will be required

• A BIG caution note here!• Each type of final finish requires a DIFFERENT primer• Incompatible primers must be removed• Especially important with intumescent fire protection.• Some steel does not need a primer – cost and environmental savings!

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011Intumescent coatings

• Acrylic

Com./arch. applications, mostly interior, field applied– water based

• longer to dry, more fragile, but “greener”, for interior

– solvant based• faster, most common use, robust, mostly interior setting

but also exterior

• EpoxyIndustrial applications, ext. or int., shop applied

• very fast to dry, very resistant (also anti-corrosion)

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Intumescent coatings have become a widely used way of expanding the application of exposed steel, but have major ramifications when specifying the level of fit and form on a project!

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011Robert R. McEwen Hospital, Toronto

(Atrium)

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011Tubes (HSS 6”X6”X3/8”)

Minutes 60 90 120 (mils*)

Thermo-Sorb 46 123 217Nullifire S605 127 NR NRNullifire S606 107 292 NRAlbi TF 119 NR 431 AD FireFilm III 130 188 257Sprayfilm III 97 173 280

* 1 mil = 1/1000th of an inch

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011Columns (W10X49)

Minutes 60 120

(mils)

Thermo-Sorb 42 204

Albi TF 55 310

A/D Fire Film III 55 NR

Nullifire S605 59 215

Spray Film WB III 56 177

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Le Casse-Tête

1213, rue Ontario est

Montréal• Rating: 1 hr• Cost of material: $6.50• Labour: $3.82

Sherwin Williams

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468 rue St-Jean, Montreal• Fire rating: 2 hrs• Material: $12.75• Preparation and

application: $14.75

Sherwin Williams

The column is actually cast-iron!

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UQAM Kimberlay Pavillon

145 President Kennedy

Montréal

Fire rating: 2 hours

Material: $15.00 /sqft

Application: $15.00 / sqft

Sherwin Williams

A thicker wall HSSwould have likelyreduced cost!

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CEMENTITIOUS/FIBROUS PROTECTION

GALVANIZING

METALIZING

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011When you need corrosion protection …

• Galvanizing• Metalizing• Paint systems• Intumescent coatings (epoxy)

• Weathering steel• Stainless steel

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THE ARCHITECT SAYS:But it looks so cool! I want it as a FINISH – can you make it

look consistent please??

THE ENGINEER AND FABRICATOR SAY ABOUT GALVANIZED STEEL:It was NEVER meant to be a “FINISH”!It is a corrosion protection system!

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Corporation Corbec

Hot-dip galvanizing is a chemical process, where iron and zinc connect.

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011Differences between heats!

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• Impurities, presence of certain chemicals, especially silicon

• Steel origin from several different heats• Thickness of material: too thin, too different

• Access to all surfaces being dipped• Size of pieces of steel

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011Calgary Water LEEDTM Gold

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ITHQ building in Montreal

Lapointe Magne / AEdifica

Galvanized steel and glass for improved energy efficiency at the new double façade.

ITHQ

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Kuujjuaq Airport, Nunavik

The vertical peripheral steel tubes are used for stabilizing the permafrost.

Fournier, Gersovitz, Moss

All the steel was galvanized (inside and outside).

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Shop

When exterior settingrequires fire-protectionand corrosion resistance

Shop appliedEpoxy basedIntumescentCoating

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Support legs covered with an epoxy intumescent coating.

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Vancouver Convention

Centre

Epoxy coating canalso be used forindoor application.

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WEATHERING STEEL

How do we detail for a material that changes its colour and finish hue over its life; can bleed onto the concrete below; is durable in some respects but can also be scratched?

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Weathering steel contains copper and nickel, is less porous than carbon steels, and creates a protective patina after about 2 years

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• It “needs” wet/dry cycles todevelop the patina• No residues should remainon the steel• Not advisable for a roof• Colour is not completelypredictable but almost always beautiful!

• Weathering steel will stain, mostly in the first two years;

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011John Deere Head officeMoline, IL1964

Weathering steel(Cor-Ten)

outside and inside building

Architect: Eero Saarinen

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ABCP Office - Québec

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Robson

Robson Square Domes aremade of stainless steel

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GENERAL ISSUES FOR CONNECTIONS

MOCK UPS – WHEN AND HOW

THE SELECTION OF CONNECTION TYPES GREATLY IMPACTS THE DETAILING AND THEREFORE THE AESS CATEGORY LEVEL

• Mock ups can be very expensive• Fabricators need to be

compensated to create these• Large mock ups can delay the

project• Remember to examine the mock

up at the same distance as the final piece will be viewed!

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0113-D rendering

Ottawa Airport• A digital rendering from the

Fabricator was more than adequate

• Architectural renderings can be used to discuss finish options as well

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011First off inspection at Toronto Airport

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011Approved first off inspection assembly

One of the “wishbones” is the full scale first off inspected assembly. Can you tell which one?

Pearson International Airport, Toronto

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SELECTING A CONNECTION TYPE

BOLTED CONNECTIONS – WHEN TO USE

• A huge impact on detailing!• Impacts fabrication costs• Impacts erection and

constructability• Impacts timing of the project• Impacts transportation• How big are the pieces• How much can be assembled in

the shop?

• Easier for fabrication• Can be less expensive• Easier for site erection• Still must be accurate in AESS for

proper fit• Makes the steel look more

“technical” – so is this the look that you want?

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WELDED CONNECTIONS

TUBULAR STEEL

• Are typically more expensive• Better results if done in the shop• More difficult to do on site, but

possible• Cleaner appearance• Difficult geometries not as hard

today with new CNC cutting methods

• Quality depends on the Fabricator

• Very popular in AESS• Can be welded or bolted• Very different overall appearance

between welding and bolting• Can be weight savings when using

HSS• When galvanizing the interior of

the tube must be coated• Can be coating/paint savings on

some applications (less surface area)

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CAST CONNECTIONS

• Castings have been used in very special projects with odd geometries

• Special castings will require special testing for strength, particularly if the connection is large

• Castings can ease the difficulty of connection of multiple tubes

• Castings are being mass produced for seismic connections

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CDP Building

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• Stress concentration• Labour intensive (labour $ > 4x material $)• Repetition (the mould is expensive)• Access to a caster and testing• Collaboration from the engineer!• Aesthetic requirement

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DESIGNING FOR CURVES,CUTS AND SPECIALTY ITEMS

BENDING

ELLIPTICAL TUBES

AESS is making use of a number of new technologies and products. This section will expand upon these to make Architects and Engineers more aware of these new possibilities so that they can make a more educated decision when selecting their Fabricator and working with them on detailing the design.

• Steel can be bent• Amount of bend a function of the

shape• Hollow sections are limited as

they can suffer buckling• W sections can also experience

web deformations• “Hard Way” vs “Easy Way” for

bending• Not all Fabricators do bending• Needs to be contracted out• Can increase costs depending on

location of bender

• These are new on the market• More common in Europe• Mostly an aesthetic choice, ratio 2:1• Narrow profile makes them slimmer

when placed in front of glazing• Similar connection issues as tubes

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Mechanical energy

Heat

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Strong axis Weak axis

http://www.youtube.com/watch?v=YYEDet4xF2M&feature=related

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HOLE PUNCHING AND DRILLING

SHEARING, PLASMA CUTTING, TORCH, ETC.

• New machinery can do almost anything!

• Check to see the state of your Fabricator’s shop and equipment

• Modern equipment has improved and automated these processes

• Accuracy is essential for AESS connections and ease of site erection

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Round holes and straight lines are theleast expensive way of creating openings.

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Erection & Challenges

~ Best Practices

~ Transportation Issues

~ Care in Handling

~ Erection Issues

~ Staging and Site Area

Requirements

~ Steel and Wood

~ Steel and Glass

Also included! Sections on:

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CISC ADVANTAGE STEEL MAGAZINEwww.cisc-icca.ca/advantagesteel

Steel and GlassIssue No. 29

Steel and WoodIssue No. 30

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Architect Engineer Fabricator

Who?

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Architect

Engineer

Fabricator

SantiagoCalatrava

WayneBaigent

GUIDE FORSPECIFYING AESS

SAMPLE AESS SPEC FORSTRUCTURAL STEEL

CODE OFSTANDARD PRACTICE

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Architect

Engineer

Fabricator

SantiagoCalatrava

WayneBaigent

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011Design process implications

• Architects and engineers have to talk to decide on AESS Categories.

• AESS Categories need to appear on all contract documents as per Spec.

• We typically expect that there will be 2 Categories specificed per structure– ex. AESS 2 upper portion of atrium, AESS 3 for the lower

portion

• Fabricators to bid on Engineering documents and the Categories specified.

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• Categories specified infer sequencing, cost and constructability issues.

• Higher level of care as provided in Code of Standard Practice.

• AESS Categories to appear on all Shop and Erection drawings.

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011Acknowledgements of committee

• Walter Koppelaar, Walters Inc., Ontario Region - Chairman• Sylvie Boulanger, CISC, Quebec Region - Secretary• Peter Boyle, MBS Steel, Ontario Region• Paul Collins, Collins Industries, Alberta Region• Michel Lafrance, Structal-Heavy Construction, Quebec Region• Graham Langford, Weldfab, Central Region• Rob McCammon, IWL Steel Fabricators, Central Region• Jim McLagan, Canron BC, BC Region• Mike Payne, Waiward Steel, Alberta Region• Rob Third, George Third and Son, BC Region• Harrison Wilson, Ocean Steel, Atlantic Region• Terri Meyer Boake, University of Waterloo - Guest• Suja John, CISC, Ontario Region• Alan Lock, CISC, Atlantic Region• Peter Timler, CISC, Western Region

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011Acknowledgements of roundtables

• Alain Bergeron, ABCP architecture• Terri Meyer Boake, University of Waterloo• Pierre Delisle, Pierre Delisle architecte• Michael Heeney, Bing Thorn Architects• Martin Nielsen, Busby Perkins & Will• Jacques White, Université Laval School of Architecture

• Peter Buchanan, Stantec• Guy Carrier, CIMA+• François Deslauriers, SDKLBB• Jean Lacoursière, Mesar Consultants• Jeff Leibgott, SBSA Structural Consultants• Sol Lorenzo, Genivar• Andrew Metten, Bush Bohlman• Bob Neville, Read Jones Christoffersen• Stéphane Rivest, Bureau d'études spécialisées (BÉS)

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Appendix 1 - CISC Code of Standard Practice

Appendix 2 - The Matrix

Appendix 3 - Sample AESS Section in Structural Steel Specification

The AESS Guide

Now available for download at : www.cisc-icca.ca/aess

The guide will also include, for convenience copies of:

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Coming November 2011!Looks at AESS as well as detailed chapters on- Timber- Glazing- Castings- Curving- Diagrids- Sustainability

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011AESS is all about communication, care …

and the little matrix.

www.cisc-icca.ca/aesswww.aisc.org/aess

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Terri Meyer Boake: [email protected]

Sylvie Boulanger: [email protected]@me.com

Thank you! Merci!

Comments and suggestions are welcome:

mailto:[email protected]



cisc architecturally exposed structural steel

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