Abstract
Due to the revision of the AIJ standard for reinforced concrete structures in 1999, 90-degree bending was defined as a 90-degree hook which assures the horizontal anchorage length to be the same as the other hooks. From this revision, AIJ JASS 5 was also revised, and it was revealed that approximately 20% of the existing column-beam joints failed to comply with the new provisions. This paper describes the validity of limiting value from the results of analysis of the reasons for these failures. On the other hand, the author proposes trials and a solution plan for the re-bar anchorage provision of beam and nonstructural element.
