The use of timber–concrete composite (TCC) bridges in the United States dates back to approximately 1924 when the first bridge was constructed. Since then a large number of bridges have been built, of which more than 1,400 remain in service. The oldest bridges still in service are now more than 84 years old and predominately consist of two different TCC systems. The first system is a slab-type system that includes a longitudinal nail-laminated deck composite with a concrete deck top layer. The second system is a stringer system that includes either sawn timber or glulam stringers supporting a concrete deck top layer. The records indicate that most of the TCC highway bridges were constructed during the period of 1930–1960. The study presented in this paper discusses the experience and per-formance of these bridge systems in the US. The analysis is based on a review of the relevant literature and databases complemented with field inspections conducted within various research projects. Along with this review, a historical overview of the codes and guidelines available for the design of TCC bridges in the US is also included. The analysis undertaken showed that TCC bridges are an effective and durable design alternative for highway bridges once they have shown a high performance level, in some situations after more than 80 years in service with a low maintenance level.
The report describes a new structural system in wood that is the first significant challenger to concrete and steel structures since their inception in tall building design more than a century ago. The introduction of these ideas is fundamentally driven by the need to find safe, carbon-neutral and sustainable alternatives to the incumbent structural materials of the urban world. The market for these ideas is quite simply enormous. The proposed solutions have significant capacity to revolutionize the building industry to address the major challenges of climate change, urbanization, sustainable development and world housing needs.
An experimental study was conducted to elucidate the effects of thermal penetration on delamination and the potential changes in failure mode of CLT. The first test series studied thermal penetration depths at various heat fluxes. The second test series consisted of single lap shear tests at homogeneous elevated temperatures followed by a...
Project contact is Pierre Blanchet at Université Laval
It is reasonable to believe that a second generation of structural products will appear, bringing new properties and promoting the use of biobased materials in the construction of tall buildings. Among the possible development options, Corruven's Vcore and H-core products could offer second-generation material developments. The proposed project will be a product design project. A specification will be established and it will identify possible properties in the CLT structural multilayer product. Prototypes will be produced and tested to characterize them. An environmental characterization under development of the products will also be realized by applying the streamlined LCA method as proposed by Heidari et al. (2017). The optimized product will be fully characterized according to the application potential in the building (mechanical, fire, acoustic).
A conversion of out-of-plane wave components into in-plane wave components at a junction may lead to increasing values of the flanking sound reduction index. The transformed components may contribute to sound radiation, if a reverse transformation occurs at a second junction...
Project contact is Angelique Pilon at the University of British Columbia
The pilot uses whole-building life cycle assessments (WBLCA) to identify major contributors to embodied carbon impacts. More importantly, the project conducts a critical analysis of the procedural requirements, information gaps, systemic barriers and other challenges for project teams seeking to use LCA as an effective tool in reducing their environmental impacts. The second phase of the Embodied Carbon Pilot project builds on the experiences and learning of Phase 1 while addressing a more common and replicable building typology. The first year, we used mass timber buildings at the University of British Columbia for the pilot LCAs and developed a protocol/strategy for adapting project information into the appropriate bill-of-materials (BOM) format for input into LCA tools, while identifying procedural challenges and barriers and variations of different material take-off methodologies and LCA tools. This second year, we will target mid-rise, multi-unit residential buildings (MURBs), a common and growing building type throughout British Columbia. Mid-rise MURBS are between 4 and 8 stories and typically use wood as one of the primary construction materials: stick-frame construction for projects under 6-stories or an increasing number of mass timber projects.
Project contacts are Xinfeng Xie at Michigan Technological University, and Xiping Wang at the Forest Products Laboratory
Two major outcomes are expected. First is the establishment of a technical basis for developing allowable bending strength and stiffness of hardwood CLT panels. Second is the development of models for predicting the mechanical properties of CLT products made of low-grade hardwood lumber.