The main objective of this study is to evaluate the heat release rate and fire growth contribution due to heat delamination characteristics of CLT manufactured with four types of adhesives used for face bonding, when exposed to a constant radiant heat flux. The evaluation is performed using the principles of ISO 5660-1 “Reaction-to-fire tests - Heat release, smoke production and mass loss rate – Part 1: Heat release rate (cone calorimeter method)”. The American version of this test method is ASTM E1354 « Standard Test Method for Heat and Visible Smoke Release Rates for Materials and Products Using an Oxygen Consumption Calorimeter ».
The long-term objective is to determine which currently accepted test methods allow for the most suitable evaluation of heat delamination characteristics of adhesives used in structural engineered wood products, based on their actual end-use applications (e.g. bending, compression, combined stress, cross-plies, etc.).
Timber-concrete composite slabs are more and more in use: the combination of timber and concrete combines the advantages of both materials and offer a valid solution for the increasing demand for sustainable construction. The connection between timber and concrete is the crucial element, yet its potential regarding material and time expenses is not exploited. This paper presents the novel connection system micro-notches, an interlocking concept between timber and concrete with indentations in the millimetre range. Micro-notches provide a continuous shear transfer without additional steel fasteners such as screws or dowels. The paper presents the development of the micro-notch concept in an extensive experimental program supplemented with analytical and numerical models, a calculation model, and practice-relevant guidelines. The results of the investigations show that micro-notches feature an approximately rigid composite action between timber and concrete and a sufficient shear strength for the use in office and residential buildings.
Building tall in wood is not a new phenomenon. In fact, Canada has a history of constructing tall wood buildings out of heavy timber and brick elements, reaching up to nine storeys. In the early 20th century, with the increase in reinforced concrete and structural steel research and construction, and with growing concerns over fire and durability, the structural use of wood fell out of common use in tall buildings. This trend is beginning to reverse, however. In the last few decades, the world has seen a resurgence of mass timber products and systems that are paving the way for tall wood buildings. This triggered an initiative by Natural Resources Canada (NRCan) to support tall wood building demonstration projects to enhance Canada’s position as a global leader in wood building construction, by showcasing the application and performance of advanced wood technologies. The Technical Guide for the Design and Construction of Tall Wood Buildings in Canada has been prepared to assist architects, engineers, code consultants, developers, building owners, and Authorities Having Jurisdiction (AHJ) in understanding the unique issues to be addressed when developing and constructing tall wood buildings.
Across B.C. and Canada, communities are under pressure to create better-performing buildings that meet stringent code requirements while reducing construction waste. Meanwhile, consumers are demanding high-quality structures that are delivered quickly and at a reasonable price. Modern methods of construction that include prefabrication can help construction professionals create buildings that meet all these criteria.
Furthermore, prefabrication provides steady employment and is good for the economy. The market opportunities are present across Canada and in the U.S., but prefabrication is not being used to its potential due to several barriers:
Negative perception of quality
Fear of innovation
Lack of information and understanding
Unclear economic benefits
Limited industry capacity
Planning and regulatory complications
A concerted effort to address these barriers includes:
Improving products through research and development
Researching, documenting, and promoting best practices
Developing guidance documents so prefabrication is easier to incorporate
Providing national-level leadership and resources to promote innovation
Successfully implementing these recommendations will require a broad and deep national perspective, an understanding of all stages and aspects of wood construction, and the vision and skills to bring together diverse experts and stakeholders.
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