Presentation given at the NASCC Conference in Orlando, Florida in April 2016

1. FUN IS IN THE DETAILS
PDH Code

2. N28A / N28B
33328/34268
Thurs/Fri

3. Terri Meyer Boake
BES B.Arch M.Arch LEED AP
Professor
School of Architecture
University of Waterloo | Canada
www.tboake.com
tboake@uwaterloo.ca

4. What is AESS?
• Architecturally Exposed Structural Steel is steel that has been
purposefully left exposed
• It must fulfill structural functions
• 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
• Proper application of the Category System will assist to make
a smoother design and construction experience

5. AESS: Primary Factors of influence
• Distance. Visibility.
• Connections mostly bolted
or welded
• Tolerances required at
fabrication and erection
• Access to detail to perform
required finish
• Interior or exterior setting
• Paint finish, corrosion
resistance, fire protection
• Degree of expression
• Size and shape of
structural elements

6. Connection types are important differentiators

7. Viewing distance is noted as the
differentiating factor between the high and
low end AESS Categories.
Grinding
permitted $$
No
Grinding!!

8. Definitions
• Member refers to the discrete sections of steel, such as wide-
flange (Universal) sections, hollow structural sections (HSS),
angles, channels, rods or cables.
• Element references the larger agglomerated pieces of a
building. This includes trusses, beams and columns as they
extend from one external connection point to the other. A small
or uncomplicated element may be constituted simply by one
steel member. In many AESS projects the additional
complexity will require the assemblage of larger elements from
a number of members.

9. Connection Types
Connections are of three basic types by virtue of their location
and purpose:
• Internal connections are those by which the members are
joined to create a larger element. These are most normally the
result of shop fabrication.
• External connections connect elements to each other. These
are most often completed on site. This includes, for example,
the connection of a truss to its supporting column or a beam to
a truss.
• Splices are to be found when elements are too large to ship in
one piece. These are often completed on site, either on the
ground prior to lifting or in the air as erection proceeds.

10. Expressed or discreet
• Connections located within an AESS element tend to be done
in ways that suppress the evidence of the connection.
• Connections between AESS elements will choose the level
and nature of the expression of the connection.
• Splices are special connections that discreetly happen within
sections of elements where the act of connecting is intended
to be hidden.
• Splices often arise as a result of the inability to transport
oversized members, hence requiring the element to be
fabricated in smaller sections that are aggregated on site.
• For more on splicing go to The Splice is Right - N87 Friday
8:00 a.m. – 9:30 a.m. // Tampa

11. Shop or site?
• Welded connections will have the best results if fabricated in
the shop
– Climate controlled environment
– Ease of access for welding operations
– Crane assist for abilities to turn and manipulate the pieces
• Bolted connections are best suited to site situations
– Quick to do
– Shortest time on the crane
– Weather independent
– Less requirements for scaffolding and temporary shoring

12. Bolted Connections
• Preferred by fabricators for site erection
• Often used when a more technical look is desired
• Simple alignment and tolerance tightening can create
quite beautiful looking connections
• Choose between regular hex head or TC (tension
control) bolts
• Ensure that all of the bolt heads are placed uniformly
in the connection

15. Stuckeman Family Building | State College, PA

16. Seattle Public Library | Seattle, WACanadian Museum for Human Rights | Winnipeg, Canada

20. Pritzker Pavilion | Chicago, IL

23. Arboretum | Penn State University

24. Seattle Public Library | Seattle, WA
Rem Koolhaas

25. Bank of America Pavilion | Boston, MA

27. Canadian War Museum | Ottawa, Canada

29. Lillis School of Business | Eugene, OR

32. National Airport | Washington, DC

35. Rose Center for Space | New York, NY

38. Federation Square | Melbourne, Australia

40. Weld Remediation
• This is the BIGGEST question!
• The AESS level determines whether or not you are permitted
to grind welds
• AESS 1 and 2 – no weld grinding permitted due to use and
distance factors
• AESS 3 and 4 – grinding permitted, but…
– THINK CAREFULLY ABOUT THE DETAILS TO DECIDE IF IT IS
ACTUALLY NECESSARY
– Neatly done welds can often be left “as is”
– DISTANCE TO VIEW can solve many potential grinding needs
– Grinding should be essential to the creation of smooth curves and not
considered routine
– Grinding requires the construction of safe working platforms and ease
of access on site

41. Kings Cross Station | London, UK

47. Roy Thomson Hall | Toronto, Canada

49. Seattle Museum of Flight | Seattle, WA

56. Pedestrian Bridge | Auckland, NZ

57. International Airport | Beijing, China

60. Perth Stadium | Perth, Australia

62. Abilities Center | Whitby, Canada

67. Edmonton City Hall | Canada

69. Intermodal Terminal | Milwaukee, WI

71. Torre Diagonale 00 | Barcelona

73. Making Splices
• Usually done between sections of larger elements
• Usually the result of transportation limitations
• Usually intended to be as unobtrusive as possible
• Downplay the connection
• Three normal ways when dealing with HSS:
– COMPLETELY REMEDIATED SPLICE BY WELDING TO
THE POINT OF INVISIBILITY
– HIDDEN CONNECTION USING BOLTS AND A COVER
PLATE
– DISCREET CONNECTION WITH EXPOSED BOLTS

78. World Financial Center Entry Pavilion | New York City, NY

92. Seattle Public Library | Seattle, WA

94. Olympic Park Station | Sydney, Australia

96. Office Building at Potsdamer Platz | Berlin, Germany

98. Masdar City | Abu Dhabi, UAE

100. Theatre | Melbourne, Australia

102. 100 Eleventh Avenue | New York, NY

104. End Connectors – Pin Connections
• Becoming a standardized detail
• Used where rotation is desired during the
erection process
• Transfers only vertical and horizontal forces
• Not moment resisting

105. Pompidou Center | Paris, France

107. Bullring Shopping Center | Barcelona, Spain

108. Heathrow Airport | London

110. Barajas Airport | Madrid, Spain

114. Ottawa International Airport | Ottawa, Canada

115. Cutty Sark Museum | London, UK

117. Neo Bankside Housing | London

118. Calgary International Airport | Calgary, Canada

121. Contemporary Cast Connections
• Used to simplify connections
• Able to locate physical (welded) connections away from areas
of high stress
• Used for special connections
• Used for standard connections
• Can be one-of large pieces formed with expendable molds (i.e.
Structural)
• Can be smaller die cast pieces made in great quantity (i.e.
glazing attachments)
• Can be solid or hollow depending on size and purpose
• Generally either NODES or END CONNECTORS

122. Image: Courtesy CastConnex

125. Brisbane International Airport | Brisbane, Australia

129. Berlin 1936 Olympic Stadium Retrofit

132. Hauptbahnhof Station | Berlin, Germany

134. Image: Courtesy Walters Inc.

137. QRC | Toronto, Canada

138. Castings designed by CastConnex

139. Transbay Center | San Francisco
Image: Courtesy CastConnex

140. Image: Courtesy CastConnex

143. Splice moved away
from point of load
transfer.

144. Image: Courtesy CastConnex

145. How to Create a Corner
• When the “corners” on an HSS tube are too rounded for the
desired aesthetic, and crispness is desired
• Usually the point when custom fabrication of the members
using plate steel is required
• Major decision on the corner will impact cost”!
– $ - Inset corner allows fillet welding
– $$ - butt corner with unremediated welds
– $$$ - butt corner with fully ground welds

146. Siemens Crystal | London, UK

148. Newseum | Washington, DC

152. Puente de Luz | Toronto

154. Arganzuela Bridge | Madrid, Spain

157. Cannon Street Station | London, UK

163. ABC Museum | Madrid, Spain

165. Tensile Connections
• Dealing with an entirely different language due to the
slenderness of the members
• Connections for rods versus cables
• Mediating the overall size of the small diameter members as
they connect to larger structural types
• Predominantly either:
– End connections (PINS) that use clevises
– Center points of cross bracing

166. Pompidou Center | Paris, France

170. Reichstag | Berlin, Germany

172. Kurilpa Bridge | Brisbane, Australia

175. Jubilee Bridge | London

177. Sony Center | Berlin, Germany

179. International Airport | Porto, Portugal

181. www.facebook.com/aess4u
For more info and great
examples to inspire your
design work, connect with
me on Facebook!

182. http://www.aisc.org/content.aspx?id=40912
Have a look at our recent
AISC Documentary
“ARCHITECTURALLY EXPOSED”
Get continuing education credits!

183. Terri Meyer Boake
BES B.Arch M.Arch LEED AP
Professor
School of Architecture
University of Waterloo | Canada
www.tboake.com
tboake@uwaterloo.ca

184. N28A / N28B
33328/34268
Thurs/Fri