In a process before being finished in a sawing factory after felled in forest, we clarified the actual situation of the carbon income and expenditure with edge materials and the fuel, and calculated the carbon balance of the house made by Nagano’s local wood. In this report, we carried out the actual survey and a hearing investigation in the laminated lumber factory and, calculated carbon balance of Japanese larch finger joint wood and glued laminated timber of eastern Nagano prefecture.
Structure-borne sound transmission across a cross-junction of double solid timber walls with a solid timber floor was analyzed in a recent research project. Both, the double walls as well as floor slab, were of so-called Cross Laminated Timber (CLT). The floor slab was continuous across the junction for structural reasons and thus, formed a sound bridge between the elements of the double wall. To gain a better understanding of the contributions of sound transmission between the wall and floor elements from the different possible paths, a thorough analysis was conducted. Hereby, direct sound transmission through, and radiation efficiencies of, the CLT elements were measured in a direct sound transmission facility; as well as, structure-borne sound transmission between CLT elements was measured on a junction mock-up. The experimental data was used as in-put data and for validation of the engineering model of EN 12354/ISO 15712 for the prediction of flanking sound insulation in buildings. The test procedures, analysis and results of this research project are presented here.
Over the past several years, a number of tall wood projects have been completed around the world, demonstrating successful applications of mass timber technologies. A survey of ten tall wood building projects in several countries was undertaken to present some common lessons learned from the experiences of four key stakeholder groups involved in the projects.
The survey was focused on the experiences of each project’s Developer/Owner, Design Team, Authorities Having Jurisdiction (AHJ), and Construction Team. It also examined the topics of project insurance, project financing and building operations and performance.
As urban densification occurs in U.S. regions of high seismicity, there is a natural demand for seismically resilient tall buildings that are reliable, economically viable, and can be rapidly constructed. In urban regions on the west coast of the U.S., specifically the Pacific Northwest, there is significant interest in utilizing CLT in 8-20 story residential and commercial buildings due to its appeal as a potential locally sourced, sustainable and economically competitive building material. In this study, results from a multi-disciplinary discussion on the feasibility and challenges in enabling tall CLT building for the U.S. market were summarized. A three-tiered seismic performance expectations that can be implemented for tall CLT buildings was proposed to encourage the adoption of the system at a practical level. A road map for building tall CLT building in the U.S. was developed, together with three innovative conceptual CLT systems that can help reaching resiliency goals. This study is part of an on-going multi-institution research project funded by National Science Foundation.
This study explores the use of Cross Laminated Timber (CLT) in a 10-story residential building as an alternative building method to concrete and steel construction. The study is not meant to be exhaustive, rather a preliminary investigation to test the economic viability of utilizing this new material to increase density, walkability and sustainable responsiveness in our built environment.
Based on international precedent, CLT is an applicable material for low-rise, as well as mid-rise to high-rise construction and has a lighter environmental footprint than traditional concrete and steel construction systems. Cross-laminated timber is a large format solid wood panel building system originating from central Europe. As a construction system it is similar to precast concrete in which large prefabricated panels are lifted by crane and installed using either a balloon frame or platform frame system. The advantages to using CLT are many, but the main benefits include: shorter construction times, fewer skilled laborers, better tolerances and quality, safer work environment, utilization of regional, sustainable materials, and reduction of carbon footprint of buildings. As a new, unproven material in the Pacific Northwest, this study investigates the cost competitiveness of CLT versus traditional materials for “low high-rise” buildings.
Hybrid construction systems proved to be valid structural solutions for the implementation of multi-storey buildings, especially if they require only the assembly of prefabricated and modular building elements. The structures here considered are designed to make different materials - firstly steel and timber - structurally collaborate, in order to develop a construction system with marked performance and architectonic flexibility features. Such systems can make the most of the heavily industrialized construction technology typical of steel systems, as well as of the advantages offered by CLT panels -lightness and structural stability- in which the timber element is recognized as an eco-friendly and eco-compatible material. Furthermore, in a sustainable urban development prospective, the use of cross-laminated timber panels, in short CLT, is recommended because wood is one of the fewest materials which has the capacity to isolate and store CO2 for a long period of time.
hygIRC 1D and 2D are hygrothermal simulation models developed at NRC Construction. hygIRC 1D is a one-dimensional version of hygIRC 2D. The objective of the task described in this report was to compare the results derived from the use the hygrothermal simulation models hygIRC 1D and hygIRC 2D to the results of a laboratory experiment (conducted as part of Task 5) to measure the drying rate of a specific wall assembly when subjected to nominally steady state conditions in an environmental chamber. The intended outcome was to duplicate the laboratory results as closely as possible as a means of benchmarking the simulation models both of which were subsequently used as part of the parametric simulation task (Task 6).
The thesis examines the hygrothermal performance of six types of high thermal resistance (High RSI) wall assemblies during environmental exposure and an air leakage (exfiltration) simulation test. These walls were installed in the Building Engineering Group's test facility (BEG Hut) located at the University of Waterloo. The High-RSI wood-frame walls were assessed by analyzing condensation, mould, and decay risks using the moisture content, temperature, relative humidity and heat flux data collected during the field test. These field-measured data were also used to calibrate one-dimensional WUFI® simulation models for each of the High-RSI assembly for use in future durability assessments using a range of North American climates. Methods were investigated to improve the predictive capacity of these simulation models as well as to increase their utility as a research tool. The design, construction and instrumentation details of the High-RSI study were also documented.