View
104
Download
0
Category
Tags:
Preview:
DESCRIPTION
The growing awareness of the environmental benefits of wood combined with advances in wood technology and manufacturing have aligned to make tall wood buildings not only possible but safe and cost effective. While the increasing number of code-approved, light-frame wood construction projects reaching five and even six stories has helped North American building professionals raise their comfort level with wood, a number of forward-looking architects, engineers, and developers are looking beyond six stories. Earn 1.00 HSW credit and 1 GBCI CE hour for LEED Credential Maintenance, visit: http://owl.li/vPEmB
Citation preview
Tall Wood Takes a Stand
Tall wood buildings proven safe and cost effective
Earn 1 AIA/CES HSW learning unit
CEU Publish Date: December 2012
Pho
to c
ourt
esy
of C
ree
Bui
ldin
gs, I
nc.
Best Practices
reThink Wood sponsors this Continuing Education Unit provided by McGraw-Hill Publishers. This course is registered with AIA CES for continuing professional education.
As such, it does not contain content that may be deeded or construed to be an approval or endorsement by the AIA of any materials of constructions or any manner of handling, using, distributing, or dealing in any material or product.
Credit earned on completion of this course will be reported to AIA CES for AIA members. Certificates of completion are available for self-reporting and record-keeping needs.
Questions related to the information presented should be directed to reThinkWood upon completing this program.
AIA Provider Number: K029AIA Course number: K1212CAIA Credit: 1 HSW/SD hour
Copyright Materials
This presentation is protected by U.S. and international copyright laws. Reproduction, distribution, display and use of the presentation without written permission of reThink Wood is prohibited.
© 2014, reThink Wood, www.rethinkwood.com
Learning Objectives
Recognize that mid-rise (six to 12 stories) and tall buildings (up to 30 stories) can be safely, efficiently, and economically built using mass timber construction techniques.
Discuss the different types of design approaches to mass timber construction for tall wood buildings.
Explain the similarities and differences between the structural composite panel and lumber products that allow building professionals to design and construct tall wood buildings.
Distinguish the differences between design approaches to accessing the acceptable structural passive fire protection measures in a mass timber building.
Table of Contents
Section 1
Tall Wood Building Report
Section 2
The Inspiration Behind Tall Wood Buildings
Section 3
What is Mass Timber Construction?
Section 4
Why Use Wood in Tall Structures
TALL WOOD BUILDING REPORTSECTION 1
Why Wood?
Cost-effective Renewable resource with lower manufacturing
greenhouse gas emissions Lowest embodied energy among major building
materials Negative carbon footprint due to wood’s carbon
storage
Photo courtesy of naturallywood.com
How Mass Timber Offers a Safe, Economical, and Environmentally Friendly Alternative for Tall Building Structures
The Case for Tall Wood Buildings
Study by Architect Michael Green of mgb and J. Eric Karsh from Equilibrium Consulting Inc.
Photo courtesy of Cree Buildings, Inc.
Tall Wood Report
We must find solutions for our urban environments that have a lighter climate impact than today’s incumbent major structural materials. The Tall Wood report is a major step in that direction. Indeed, it introduces the first significant challenge to steel and concrete in tall buildings since their adoption more than a century ago.
- Michael Green, Architectmgb
“
”
THE INSPIRATION BEHIND TALL WOOD BUILDINGS
SECTION 2
Environment
Photo courtesy naturallywood.com.
“Architects are realizing that the old ways of doing things will not continue to work; we are ruining the environment. Because of this, we’re now seeing an industrial revolution for wood. Wood is a renewable product that can do much more than we have yet asked of it.”
- Nabih Tahan, AIA,with Cree Buildings, Inc.
Advancements in Mass Timber Building Techniques
Cross laminated timber (CLT)
Laminated veneer lumber (LVL)
Laminated strand lumber (LSL)
Glued laminated timber (Glulam)
Rendering courtesy of mgb
Cross Laminated Timber(CLT)
Engineered wood panel
3, 5 or 7 layers of dimension lumber oriented at right angles to one another then glued to form structural panels
Exceptionally strong, dimensionally stable and rigid
Photo courtesy of naturallywood.com
Laminated Veneer Lumber(LVL)
Thin wood veneers bonded together
Wood grain oriented parallel to the length of the member
Predictable structural performance and dimensional stability
Free from warping and splitting
Photos courtesy of naturallywood.com
Laminated Strand Lumber(LSL)
Engineered structural composite lumber
Thin chips or strands of wood up to 6” in length glued under pressure
Wood grain oriented parallel to the length of the member, then machined to finished sizes
Strong when face- or edge-loaded
Photo courtesy of naturallywood.com
Glue Laminated Timber (Glulam) Composed of individual wood laminations
Bonded together with durable, moisture-resistant adhesives
Grain runs parallel with length of member
Used horizontally as a beam or vertically as a column
Photo courtesy of naturallywood.com
Bridport House
Location: Hackney (London), UK
Architect: Karakusevic Carson Architects
Contractor: Willmott Dixon Group
Timber Engineer: EURBAN
Year of completion: 2011
Developers chose to use wood for Bridport House for several reasons: structural capabilities of CLT, speed of construction, and environmental advantages. When it was completed in 2011, this eight-story structure formed the largest timber-built apartment block in the world.
Photo courtesy of Karakusevic arson Architects
WHAT IS MASS TIMBER CONSTRUCTION?SECTION 3
Mass Timber Construction
Uses large prefabricated wood members such as CLT, LVL and LSL for walls, floors and roof
Glulam for beam and columns applications
Engineered for strength
Photo courtesy of naturallywood.com
CLT Panels
Resists high racking and compressive forces
Cost effective for multi-story and long-span diaphragm applications
Photo courtesy of Land Lease
At 10 stories, Forté in Melbourne, Australia, was the tallest timber apartment in the world when it was completed in 2012.
LifeCycle Tower
Prefabricated hybrid wood / concrete slab system
Central stiffening core for elevator, stairs and shafts
Glulam posts on exterior
Structures up to 30 stories
LifeCycle Tower ONE’s prefabricated hybrid wood / concrete slab system is supported by
a central stiffening core on the interior and by glulam posts on the exterior.
Photo courtesy of Cree Buildings Inc.
Finding the Forest Throughthe Trees (FFTT)
Uses mass timber panels and glulam as primary structural members to achieve potential building heights of up to 30 stories
‘Strong column-weak beam’ balloon-frame approach
Building performs well under wind and seismic loading conditions
Structures up to 30 stories
Quick installation
Rendering courtesy of mgb
WHY USE WOOD IN TALL STRUCTURESSECTION 4
Environmental Benefits
Grows naturally and is renewable
Photos: naturallywood.com
Forté
Location: Melbourne, Australia
Architect / Contractor / Developer: Lend Lease
Year of completion: 2012
Rising 10 stories, Forté is Australia’s first CLT building and first high-rise timber apartment. Lend Lease cites the environmental benefits as their primary reason for building the tall building out of wood. Speed of construction was a huge benefit to the global company – with an estimated cut in construction time of 30 percent.
Photo courtesy of Lend Lease
LCA and Wood
Wood outperforms other materials in terms of embodied energy, air
and water pollution, and greenhouse gas emissions.
Source: Data compiled by the Canadian Wood Council using the
ATHENA EcoCalculator with a data set for Toronto, Canada.
The Carbon Connection
As architects, we have to ask ourselves: Is there a material that minimizes or eliminates carbon in the environment?
-- Michael Green, MAIBC, AIA, MRAIC
Michael Green Architecture
“ “
Prince George Airport
British Columbia
Architect: mgb
Photo: mgb
Cost Competitive
Cost competitive up to 30 stories
Different configuration choice offers flexibility
Installed much quicker leading to faster occupancy
Photo courtesy of Land Lease
Development company Lend Lease estimates that the $11-million
Forté apartment building in Melbourne, Australia was built 30 percent faster because
the materials were prefabricated.
Applewood Pointe at Langton Lake
Location: Roseville, Minnesota
Architect: JSSH Architects
Occupancy: 48 units
The 48-unit four-story wood structure had a one-hour fire rating; it was sited over a three-hour rated pre-cast concrete parking garage, for a total of 123,964 square feet. According to Roger Johnson with JSSH Architects of Minnetonka, Minnesota, wood-frame was the most cost-competitive option, at $80 per square foot complete.
Photo courtesy of Applewood Pointe
Cost Benefits
Emory Point
Location: Atlanta, Georgia
Structural Engineers: Ellinwood + Machado Consulting Structural Engineers
Occupancy: 442 units
Type of construction: One five-story wood-frame building over slab-on grade and three four-story wood-frame buildings over one-story concrete podiums
A number of systems were considered, and wood was the most economical. For the structural frame portion only, the wood design cost approximately $14 per square foot compared to $22 per square foot for a 7-inch post-tensioned concrete slab and frame. The huge wood-frame project was completed in just over a year, which provided additional cost savings.
Photo courtesy of Ellinwood + Machado Structural Engineers
Fire Safety
Two design approaches to access structural passive fire protection measures
1. Encapsulation
2. Charring
Research shows mass timber buildings behave very well in fire
Photo: iStock (stock)
Advances in building science and fire suppression systems have expanded the scope and role for wood structural and finish materials.
CLT Fire Testing Results
American Wood Council test on a load-bearing five-ply CLT wall
Test specimen lasted 3 hours, five minutes & 57 seconds
Well beyond the two-hour goal
Photo: FPInnovations
Shake Table Test – Six Story Wood Building
In 2009, a full size prototype of a six-story wood-frame building successfully passed a seismic ‘shake table’ test conducted in front of 400 international observers in Japan. Subjected to seismic forces greater than those of the 1995 Kobe earthquake, the structure suffered no visible damage.
Photo courtesy of IVALSA
Acoustics
The mass of the wall contributes to its acoustic performance
Additional acoustic benefits with sealants and other types of membranes to provide air tightness used by builders
CLT Handbook, FPInnovations, 2011
Mass timber building systems provide appropriate noise control for both airborne and impact sound transmission.
Photo courtesy of Karakusevic Carson Architects
Building Height Considerations
Mass timber buildings have minimal shrinkage over time
The 10-story Forté project used a conventional platform-based CLT system.
Photo courtesy of Land Lease
Code Approvals
U.S. and Canadian building codes do not explicitly recognize mass timber systems – this does not prohibit their use
2015 edition of the IBC will recognize CLT products when they are manufactured according to the new ANSI/APA standard
CLT walls and floors permitted in all types of combustible construction
LifeCycle Tower ONE
Location: Dornbirn, Australia
Architect / Contractor / Developer: Cree GmbH
Year of completion: 2012
When Cree GmbH developed their LifeCycle Tower system, they knew the best way to sell the concept was to prove its viability. Wood’s environmental and structural benefits were key considerations for LCT ONE.
Photo courtesy of Cree Buildings, Inc.
Responsible Revolution
Tall wood buildings are not only possible, but the design and build concepts are being proven around the world.
Photo courtesy of Cree Buildings, Inc.
Photo courtesy of Karakusevic Carson Architects Rendering courtesy of mgb
Photo by David Lena;courtesy of HMC Architects
For more information on building with wood, visit rethinkwood.com
THANK YOU!
Recommended