破面解析に基づく高さの確率密度関数を用いた新旧コンクリート界面における機械的性質の新しい評価指標

摘要

コンクリート構造物には打継ぎをはじめ耐震補強や劣化補修などで，新旧コンクリート間に界面が生じる。そのような界面では，一体化しているコンクリートとは異なり，界面ごく近くで破壊が進展し，構造性能が格段に低下する1）,2）。性能低下を抑制できるようにするためには実験を繰り返すだけでなく，基礎的な検討，とりわけ界面の破壊機構解明が効果的な場合が多い。%This study discusses an effective parameter for the mechanical properties of new-to-old concrete interface of concrete specimens. The authors employed probability density function (PDF) of the height of fractured surface and the standard deviation from it for discussion, which is the main feature of this study. The conclusions are as follows.rn1. The fractured surface of newto-old concrete interface is able to be modeled to a specific shape (such as a square pyramid or a square pillar) by evaluating the PDF of the height of the fractured surface and finding the same PDF of the specific shape. Modeling the real fractured surface to such a simplified surface body to a dowel has a potential to clarify the mechanical properties of the interface.rn2. The standard deviation (Sd) calculated from the PDF of the fractured surface and some parameters employed in the previous studies (such as roughness parameters and fractal dimensions) have a close relation. The Sd value of the specimen is a better parameter than the ones used in the previous studies for evaluating the mechanical properties of newto-old concrete interface.