To achieve the fire resistant wooden structure, we have proposed the wooden structural members(column and beam) composed of three layers,"load-bearing part, self-charring-stop layer, and surface layer". A high-density wood or a high heat capacity material for a self-charring-stop layer is sandwiched between a load-bearing part and a surface layer. Since these materials absorb heat from surface layer, self-extinguishment can be expected. In this paper, we performed a series of experimentations for the wooden structural members consist of three layers, made of Japanese cedar. It is well known that a Japanese cedar is one of the lowest fire resistant timber materials among the woods. The test specimens are composed of Japanese cedar for load-bearing part and surface layer, and mortar for self-charring-stop layer. Mortar pieces are arranged mutually with cedar in the self-charring-stop layer. One-hour fire resistant tests under loading for 3 column specimens and 3 beam ones show good self-charring-stop behaviors, we were convinced the effect of installing mortar pieces in the wooden structural members.
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