전단보강근이 배근된 외부 보기둥 접합부에 정착된 헤드 철근의 스트럿-타이 모델

Strut-And-Tie Model for Headed Bar Anchored in Exterior Beam-Column Joint with Transverse Reinforcement

This study presents a strut-and-tie model for the development of headed bars in an exterior beam-column joint with transverse reinforcements. The tensile force of a headed bar is considered to be developed by head bearing together with bond along a bonded length as a partial embedment length. The model requires construction of struts with biaxially compressed nodal zones for head bearing and fan-shaped stress fields against neighboring nodal zones for bond stresses along the bonded length. Due to the existence of transverse reinforcements, the fan-shaped stress fields are divided into direct and indirect fan-shaped stress fields. A required development length and head size of a headed bar can be optimally designed by adjusting a proportion between a bond contribution and bearing contribution.