Hirokazu Ohashi, Shinya Igarashi and Tsutomu Nagaoka
As forestry contributes to the reduction of greenhouse gases by CO2 fixation, in recent years, use of wood in buildings has attracted all over the world more attention. However…
Abstract
Purpose
As forestry contributes to the reduction of greenhouse gases by CO2 fixation, in recent years, use of wood in buildings has attracted all over the world more attention. However, construction of large wood structures is almost inexistent within urban areas in Japan. This is due to the Japanese law on fire protection of wood buildings in cities, which is considered very strict with severe requirements. This paper aims to present a research work relative to the development of one-hour fire-resistant wood structural elements for buildings in cities. The developed elements are composed of three layers made of laminated timber.
Design/methodology/approach
These wood structural elements, made of glued laminated timber with self-charring-stop, have sufficient fire resistance during and after a fire and comply with the strict Japanese standard for wood structural elements, which stipulates that such elements have to withstand the whole dead-load of concerned buildings after fire. To comply with such requirements, new elements of glued laminated timber with self-charring-stop layer were developed, and their performance was confirmed. Several fire-resistant tests conducted on columns, beams, column-beam joints, connections between beams and walls and beams with holes were carried out.
Findings
All tests proved that the elements have sufficient fire resistance. No damage was found out at the load-bearing part of the elements after testing. As the developed elements have two layers protecting the load-bearing part, the temperature in the load-bearing part could be retained below 260°C (carbonization temperature) and provide the elements with a sufficient fire resistance for 1 h.
Practical implications
These wood structural elements have already been applied in six projects, where large-size wooden buildings were constructed in urban areas in Japan.
Originality/value
The proposed structural elements use a novel technique. Every wooden element is composed of three layers made of glued laminated timber. The elements have a typical performance of self-charring-stop after fire without need for water of firefighters. More technologies related to these elements, including column-beam joints and beams with holes and effect of crack, were also developed to design and construct safe wooden buildings.
Details
Keywords
H. Binner, H.T. Law, N. Sinnadurai, G. Jones and P.E. Ongley
Following the discussion at our recent Annual General Meeting, a questionnaire was sent out to all members. Almost half of them replied despite the fact that the time allowed for…
Abstract
Following the discussion at our recent Annual General Meeting, a questionnaire was sent out to all members. Almost half of them replied despite the fact that the time allowed for returning the questionnaire had been kept very short. Some members even provided detailed comments.