Development of Wood Structural Elements for Fire Resistant Buildings

Abstract

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 presents a research work relative to the development of fire resistant wood structural elements for buildings in cities. 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. 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. These wood structural elements have already been applied in six projects, where large-size wooden buildings were constructed in urban areas in Japan.