Evaluating method of axial load carrying capacity of reinforced concrete columns failing in shear considering reinforcing details

本研究的最终目的是防止大地震条件下R/C老建筑的煎饼式倒塌。为此，本文研究了受弯破坏柱的轴向承载能力。研究范围扩展到剪力破坏柱、残余变形下的轴向承载力和配筋细部的影响。对10个方形截面的R/C试件进行了试验。两种类型的试件仅采用不同的加固细节。h系列机箍为135度钩。p系列的箍有90度的钩状细节。另一个主要变量是加载方法；即单调中心轴向加载、恒定横向漂移下的偏心轴向加载和恒定轴向加载下的正常反向轴向加载。主要结论如下。(1)高轴向载荷的试件在轴向变形远未达到中心轴向载荷下试件的轴向-轴向变形关系时，已失去预定轴向载荷。另一方面，低轴向载荷的试件在其轴向变形达到具有中心轴向载荷的试件的轴向-轴向变形关系时，失去了预定轴向载荷。(2)配筋细部正常（h系列）与配筋细部差（p系列）试件的行为差异不大。

Final objective of this study is to prevent pancake type collapse of R/C old buildings during sever earth quake. For this purpose axial load carrying capacity of columns failing in flexure have been studied. In this study the scope was extended to shear failing columns, axial load capacity under residual deformation and effects of reinforcing details. Ten R/C specimens with square sections were tested. Two types of specimens were made with varying only reinforcing details. The hoop of H-series had 135 degrees hook. And the hoop of P-series had 90 degree hook details. Another main variable was loading methods ; i.e.monotonic centric axial loading, eccentric axial loading under constant lateral drift and normal reversed lateral loading under constant axial load. Main conclusions were as follows. (1)Specimens with high axial load lost scheduled axial load far before it's axial deformation reached axial load-axial deformation relation of specimen with centric axial load. On the other hand, Specimens with low axial load lost scheduled axial load when its axial deformation reached axial load-axial deformation relation of specimen with centric axial load. (2)There was little difference of behavior between specimens with normal reinforcing details (H-series) and those with poor reinforcing details (P-series).