Use of engineered wood products, particularly structural glued laminated timber and/or cross-laminated timber (CLT) , is indispensable for recent large-scale wooden buildings. Durability of adhesion of these materials is quite important for assurance of reliable mechanical properties throughout their service life. Therefore, only some highly reliable adhesives are permitted for use. Resorcinol resin adhesive has been used for a long time as a load-bearing structural wood adhesive. In addition,

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... ew structural adhesives such as the aqueous polymer-isocyanate adhesive developed in Japan and onecomponent polyurethane adhesives for structural use developed in Europe have recently been initiated for use in structural glued laminated timber and CLT. These isocyanate-based resin adhesives are different from resorcinol resin in terms of their chemical structure and physical performance. Therefore, the requirement of bond qualities of structural wood adhesives has been reconsidered, and standards have also been maintained in each country. Here the present standards for structural wood adhesives and evaluation methods for their bond performance are reviewed. : engineered wood products, structural wood adhesives, JAS, JIS, polyurethane adhesives. 近年の大規模木造建築物には,大断面の構造用集成材や Cross-Laminated Timber(CLT)の ような構造用木質材料の使用が不可欠である。構造用木質材料の強度性能を設計通り発揮させる ためには,接着が適正に行われていることが前提となり,使用する接着剤も耐久性への信頼が高 いものに限られる。構造用木材接着剤としては,長い間レゾルシノール系樹脂接着剤などが使わ れてきたが,近年水性高分子−イソシアネート系接着剤や,最近欧米では1液ポリウレタン接着 剤も使われ始めている。これらイソシアネート基の反応をベースとした接着剤は,レゾルシノー ル系接着剤とは化学構造や物性が異なる。したがって,構造用木材接着剤の要求性能や評価法に ついて再検討する必要があり,規格も各国で整備されつつある。そこで本稿では,現行の構造用 木材接着剤に要求される接着性能に関する規格とその評価法について概説する。 *1