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.
Cross-laminated timber (CLT), a new generation of engineered wood product developed initially in Europe, has been gaining increased popularity in residential and non-residential applications in several countries. Many impressive low- and mid-rise buildings built around the world using CLT showcase the many advantages this product has to offer to the construction sector. In this Chapter, we put forward an introduction to CLT as a product and CLT construction in general, along with different examples of buildings and other structures made with CLT panels. CLT is now available in North America and several projects already built in Canada and the United States, using CLT, are presented in this Chapter. An assessment of market opportunity for CLT based on the latest construction statistics for the United States is also presented.
This Chapter provides general information about the manufacturing of CLT that may be of interest to the design community. The information contained in this Chapter may also provide guidance to CLT manufacturers in the development of their plant operating specification document. Typical steps of the CLT manufacturing process are described, and key process variables affecting adhesive bond quality of CLT products are discussed. The manufacturing, qualification, and quality assurance requirements in accordance with the American National Standard for Performance-Rated Cross-Laminated Timber, ANSI/APA PRG 320, are discussed.
Cross-laminated timber (CLT) construction is a relatively new process. There is therefore very little specific technical documentation for the erection of structures designed and built with CLT panels. Current CLT manufacturers provide recommendations on lifting systems for the installation of prefabricated wood assemblies. However, technical documents currently available mostly come from Europe or Canada and may appear incomplete to some design professionals and builders/contractors in the United States. This Chapter presents a variety of lifting systems that can be used in the construction of structures using CLT panels. We discuss the basic theory required or suggested for proper lifting techniques. In addition, we introduce various tools and accessories that are frequently required for CLT construction, as well as good building practices to help contractors build safe and efficient CLT panel structures. Finally, we discuss issues related to the transportation of CLT assemblies from factory to building site. Regulatory aspects of transportation are also discussed. It is importat to note that the lifting, handling, and installation of CLT panels involve multiple interest groups including design professionals, contractors/erectors and CLT manufacturers, each with different areas of interest and expertise. Therefore, the information presented in this Chapter is broad in scope and may or may not be relevant to each interest group.
The U.S. edition of the CLT Handbook is a 572-page guide and is the definitive handbook on cross-laminated timber (CLT), covering manufacturing, structural design, connections, fire and environmental performance and the lifting and handling of CLT elements.
Firstly, the two-dimensional construction product cross-laminated timber (BSP or XLAM) is described as having regard to its manufacture and its properties. This is followed by the basic principles, the description of the structural behavior, and the fire performance with associated modeling assumptions and characteristic material values according to the safety concept of the Eurocodes...