異形鉄筋のコンクリート内の定着性状に及ぼす拘束の効果に関する実験的研究

摘要

Vertical wall reinforcing bars of a boxed wall precast concrete structure in Japan must be anchored straight in the foundation beam. Sometimes, the beam width may not be sufficient to develop anchorage strength in the concrete although the AIJ(Architectural Institute of Japan)Standard for Structural Calculation of Reinforced Concrete Structure requires minimum concrete volume for the development of deformed bars. A series of pull-out tests were carried out to investigate structural performance of anchored bars using various prototype specimens. The purpose of the test series was to study the effect of various parameters and to clarify the failure mechanism. A new series of tests were carried out using high strength deformed bars and varying the foundation beam widths. The anchored bars were pulled out from the base beam exhibiting the relationship between maximum bond stresses and flexural stresses with in the beam.%鉄筋コンクリート構造における鉄筋の定着は鉄筋径に対して十分なコンクリートの体積があることを前提にして，その設計方法がRC規準に規定されている。また壁式鉄筋コンクリート造設計·計算規準·同解説においてはRC規準に解説している必要定着長実験式で，スラブや直交壁の拘束の有無の係数を代入する，定着長の標準設計式を規定している。