We developed a one-hour fire-proof glulam made of Japanese cedar and got the authorization as abuilding material from the Minister of Land, Infrastructure and Transportation. We also succeeded to give one-hour fire performance to cross laminated timber (CLT) using the same concept. The both structures consist of three parts which are load-bearing part, fire-die-out part and surface part. Therefore, we challenged two-hours fire-resistive glulam using the same concept. We used not only drill but also CO2 laser as an incising for lamina of fire-die-out parts and impregnated the fire retardant evenly for diffusion. The main reason to use drill is that the handling of CO2 laser is not so easy for glulam manufacturer. Comparisons of fire-performance between fire-die-out parts whose lamina were incised by drill and CO2 laser, and finger jointed load-bearing part made of Japanese cedar and larch were also achieved using the same glulam whose fire-die-out part is 90 mm in total thickness. The fire test was achieved in a furnace in accordance with a standard heating curve by ISO 834-1. Though this glulam failed two-hours fire performance by a little char and discoloration, we could know the difference in incising method and density of load-bearing part.
The charring behavior of timber structural elements, such as the charring rate of timber elements and delamination of glue-laminated timber, affects the structural stability of timber buildings. The charring rate of timber elements varies depending on the severity of fire exposure. However, charring rates have been ordinarily investigated in fire tests under the standard fire exposure defined by ISO 834. It is important to accumulate and analyze data on the charring behavior of timber elements under actual fire exposure. The aim of this study was to clarify the charring behavior of glue-laminated timber structural elements exposed to actual fire in full-scale fire tests of three-story timber school buildings. Charred and uncharred areas of the timber structural elements were carefully observed and investigated after the fire tests. The charring rates of timber elements in full-scale fire tests ranged from 0.6 mm/min to 1.3mm/min. The charring rates were greater than the nominal charring rates reported in past studies because of preheating and severe fire exposure.
The combustibility of timber is one of the factors that restrict the use of structural elements of wood in buildings in Brazil. This paper describes an experimental investigation of the charring rate of wood species. The charring rate is one of the key parameters for the design of load bearing timber structures. The purpose of this study is...
Vertical gypsum fire separation walls that have fire-resistive ratings evaluated in accordance with a recognized standard are permitted for use in building construction. When approved doors are inserted in such walls, the details must be presented for consideration as an “alternative solution”.
This guide is based on observations of two CAN/ULC S101 (ULC, 2007) tests on gypsum fire separation walls with S104 (ULC, 2010) approved closure penetrations. The guidance is intended to direct the designer’s attention to potential issues that might impact the performance of a closure penetration in a gypsum separation wall that use a thick wood-based sheathing (i.e. combustible) for carrying the weight of the fire door assembly. General guidance is provided on sizing the sheathing and the need for protecting the sheathing from fire, yet permitting the assembly to accommodate building movements in-service.
The purpose of this guide is to recommend considerations when designing the interface between a fire door (closure penetration) in proprietary gypsum separation walls. These considerations form only part of the alternative solution that will need to be presented to the AHJ for approval.
Although details are provided in Appendix VI to illustrate a possible solution, it is the responsibility of the designer to understand how the design is expected to perform. The guide discusses three scenarios to assist the designer in formulating an appropriate solution. These are performance under an extreme fire; performance under a limited fire; and performance under normal (non-fire) service conditions that may include high wind or high seismic event.
A large-scale fire test was conducted on a compartment constructed from cross laminated timber (CLT). The internal faces of the compartment were lined with non-combustible board, with the exception of one wall and the ceiling where the CLT was exposed directly to the fire inside the compartment. Extinction of the fire occurred without intervention. During the fire test, measurements were made of incident radiant heat flux, gas phase temperature, and in-depth temperature in the CLT. In addition, gas flow velocities and gas phase temperatures at the opening were measured, as well as incident heat fluxes at the facade due to flames and the plume leaving the opening. The fuel load was chosen to be sufficient to attain flashover, to achieve steadystate burning conditions of the exposed CLT, but to minimize the probability of uncertain behaviors induced by the specific characteristics of the CLT. Ventilation conditions were chosen to approximate maximum temperatures within a compartment. Wood cribs were used as fuel and, following decay of the cribs, selfextinction of the exposed CLT rapidly occurred. In parallel with the large-scale test, a small scale study focusing on CLT self-extinction was conducted. This study was used: to establish the range of incident heat fluxes for which self-extinction of the CLT can occur; the duration of exposure after which steady-state burning occurred; and the duration of exposure at which debonding of the CLT could occur. The large-scale test is described, and the results from both the small and large-scale tests are compared. It is found that selfextinction occurred in the large-scale compartment within the range of critical heat fluxes obtained from the small scale tests.
An experimental study of the influence of an exposed combustible ceiling on compartment fire dynamics has been performed. The fire dynamics in compartments with combustible cross-laminated timber ceilings vs non-combustible reinforced concrete ceilings in otherwise identical compartments with three different ventilation factors were investigated. The experimental results are compared against predictions from two theoretical models for compartment fire dynamics: (a) the parametric fire model given in EN 1991-1-2, and (b) a model developed at Technische Universität Braunschweig, which are the parametric fire models currently used in Germany. It is confirmed that the introduction of a combustible timber ceiling leads to higher temperatures within the enclosure, both under fuel-controlled and ventilation-controlled scenarios. It is also demonstrated that the theoretical models considered in this article require refinement in order to adequately represent all relevant scenarios when combustible ceilings are present. A refinement of the German model, by adding the fuel from the combustible ceiling to the occupancy fuel load, was shown to not adequately capture the response for the ventilation-controlled fires.
This InfoNote summarizes recent research and work in progress. A significant amount of fire research has been conducted on mass timber over the last 10 years in Canada. This has supported the successful design and construction of numerous low-, mid-and even high-rise wood buildings. This has also fostered the introduction of new provisions into the National Building Code of Canada which has made wood and mass timber construction more accessible. However, the fire performance of these systems remains a concern for many potential occupants or owners of these buildings, not to mention building officials and fire departments. Research at FPInnovations continues to support designers and builders in the use of mass timber assemblies by ensuring fire safe designs.