繊維複合した軽量気泡コンクリートの破壊靭性およびAEスペクトラム解析

概要

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The fiber reinforced Autoclaved Lightweight Concretes (ALC) produced by using the wood fibers and the alkaline-resistance glass fiber were evaluated the fracture toughness by notched 3-points bending test. In addition, the spectrum of acoustic emission (AE) events detected during deformation were analyzed and were classified. The classified spectrum types were correlated with the fracture mechanism. Most of fibers were pulled-out during fracture. Toughness of fiber reinforced ALC, therefore, depends upon fiber length and bonding strength between fiber and matrix. It is considered that bonding strength of wood fiber is larger than that of alkaline-resistance glass fiber. Reinforced ALC using wood fiber of 3 mm length is tougher than one using alkaline-resistance glass fiber of 10 mm length. AE spectrum were classified into three types by the frequency component. First spectrum group (type I) which had low energy occurred from the early stage of loading. Type I is caused by the microcrack formation in the matrix. Second group (type II) and third group (type III) which had a very wide distribution of energy occurred from non-linear behavior. Type II is caused by the coalescence among microcracks or by the crack propagation. Type III which is peculiar to fiber reinforced ALC is caused by the debonding and the friction around fiber.
社団法人日本建築学会の論文
1987-11-30