Wooden constructions are on the rise again – encouraged by a strong trend towards sustainable and resource efficient buildings. Load-bearing timber-glass composite elements – a novel concept to use the in-plane loadbearing potential of glass – could contribute to a more efficient use of materials in façades. The current study relates to...
The thermal refurbishment of the building stock is one of the most fundamental challenges of sustainable urban development. Particularly the use of natural and local materials gets an increasing relevance, regarding the embodied energy. The focus of this work is the development of systematised solutions for thermal refurbishment with...
Project contact is Erica Fischer, Oregon State University
Summary
Previous large-scale fire testing of mass timber buildings has occurred on a single floor of a building. The data collected from these experiments were used to demonstrate the fire performance of cross-laminated timber (CLT) buildings and to change the International Building Code (IBC) prescriptive fire protection design provisions for mass timber buildings. The scope of the tests was limited to compartment fires with varying levels of encapsulation. However, multi-story mass timber buildings are being constructed in the United States and fire science experts understand that fire threats can move beyond compartment fires and into travelling (moving fires) and vertical fire spread. In addition, many buildings are being proposed outside of the scope of the IBC prescriptive fire protection design approach (i.e. open floor plans), thereby requiring the employment of performance-based structural fire engineering. Performance-based structural fire engineering requires quantifying fire demands within the structure and calculating the resistance of the structure throughout the fire to provide safety to the occupants during egress, safety to fire fighters during and after the fire, and to ensure the building will not collapse introducing a threat of fire spread and damage to the surrounding buildings. To date, engineers are employing performance-based structural fire engineering on mass timber buildings; however, engineers are typically forced to make simplifications, be very conservative, and/or frequently use unproven assumptions. These simplifications and assumptions need to be tested experimentally to ensure that engineers are providing adequate levels of safety. Some of these assumptions include exterior wall and façade details that can prevent vertical fire spread, and detailing by engineers that considers the effects of charring during the decay phase of the fire.
The PIs have an opportunity to perform large-scale fire tests on a multi-story mass timber building in Corvallis, OR. Future large-scale fire tests will utilize a portion of the 10-story building being tested as a part of the Natural Hazards Engineering Research Infrastructure (NHERI) Tall Wood project (http://nheritallwood.mines.edu/). After the seismic testing of the 10-story building, the top four stories will be demolished and not utilized. Therefore, the research team will transport these floors to Corvallis to be re-assembled at the Corvallis Fire Training Center. In this preliminary stage, a multi-disciplinary team will perform computer simulation modeling of the fire tests, fully develop the scope of the tests and create a detailed experimental plan for the large-scale fire tests. The tests will be designed with considerations for the ability to address the following questions. These questions are consistent with future research needs that were identified by the Forest Products Laboratory [5] and the recent National Fire Protection Association (NFPA) Fire Safety in Tall Timber Buildings Workshop.
(1) How does the façade detailing of a mass timber building influence the vertical fire spread behavior?
(2) How can engineers better design mass timber buildings to enhance the safety for firefighters?
(3) How do glulam beam-to-column connections perform in real fires?
(4) What engineering solutions can be implemented within mass timber buildings to account for the behavior of the mass timber during the decay phase of the fire in the case that suppression is not available?
(5) How can engineers better design mass timber buildings to enhance the safety for fire fighters during the firefight and during overhaul/investigation?
The considerable increase in the architectural demands for highly transparent and load-bearing structures have recently resulted in the development of an innovative hybrid structure. This article provides a review of design parameters for Timber-Glass composite facades. The design/architectural question, which arose in the project, was how...
The project included product development and materials research. The aim was to produce a wooden façade system with an attractive modern appearance and good constructive design with the help of modern woodworking technology. Important requirements to consider were that the system should have a contemporary, attractive expression and that the façade system should provide a product with high quality ambitions in terms of environmental impact. It should also be flexible and easy to use for architects and designers who want to create unique façades. The main focus in this study was about the visible wood surface appearance where the intention was to create a varied surface with interesting innovative designs, with a method that make it possible to always create new patterns. Two different façade cladding systems were developed by combining woodcraft tradition, new research, digital design tools and industrial processes in the wood construction industry. Prototypes with patterned surfaces on both individual boards joined together and on a system based on multi-layer solid wood panels were tested.
Structural solutions involving the mechanical interaction of timber and glass load-bearing members showed a progressive increase in the last decade. Among others, a multipurpose hybrid facade element composed of Cross-Laminated Timber (CLT) members and glass panels interacting by frictional contact mechanisms only was proposed ion the framework of the VETROLIGNUM project. While demonstrating enhanced load-bearing and deformation capacity performances under seismic loads, facade elements are known to represent a building component with multiple performance parameters to satisfy. These include energy efficiency, durability, lightening comfort and optimal thermal performance. In this paper, a special focus is dedicated to the thermal performance assessment of CLT-glass facade modules under ordinary operational conditions. Based on the thermal-chamber analysis of small-scale prototypes, reliable Finite Element numerical models are developed and applied to full-scale VETROLIGNUM solution. Sensitivity analyses are hence carried out to explore the actual thermal performance of these novel hybrid systems.
Canadian Conference on Building Science and Technology
Research Status
Complete
Summary
On tall wood buildings, mass timber elements including CLT, NLT, glulam, and other engineered
components absolutely need to be protected from excessive wetting during construction. This requirement precludes the use of many conventional cladding systems unless the building is fully hoarded during construction.
The building enclosure and façade of UBC Tallwood House consists of an innovative prefabricated steel stud rainscreen curtain-wall assembly that is pre-insulated, pre-clad, and has factory installed windows. Design of connections and air and water sealing of panel joints and interfaces was carefully considered given the tall wood structure they were designed to protect. While steel studs were utilized in the panelized structure, feasible curtain-wall designs were also developed and prototyped for wood-framing, CLT, and precast concrete as part of the project.
Looking ahead, there will continue to be innovation in design and construction of fast and durable facades for taller wood buildings. New prefabricated panel designs incorporating CLT panels and connection technologies from unitized curtainwall systems are already being developed for the “next tallest” wood buildings in North America.
Up to now, structural sealant glazing façades have been extensively applied. They are at the cutting edge of technology and meet the highest standards. The objective of several research projects was to develop stiffening glass fronts, which replace expensive frameworks or wind bracings behind the large glass windows. Thus, potential applications...
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