Shear & Torsion

[2095] EVALUATION ON SHEAR FAILURE MECHANISMS OF A RC COLUMN WITH CUT-OFF BARS BASED ON E-DEFENSE EXCITATION

Zhongqi SHI¹, Kenji KOSA², Tatsuo SASAKI³ (1.九州工業大学大学院工学府 2.九州工業大学建設社会工学科 3.大日本コンサルタント技術統括部)

Keywords:cut-off LG bars, E-Defense, failure mechanisms, RC column

Experimental test on a RC column with cut-off LG bars was performed. In this study, the damage condition and the failure mechanisms were summarized and evaluated in details. It was found that due to flexural yield of several LG bars at upper cut-off position, the horizontal cracks developed through until about half of the section firstly at the just point of upper cut-off position. The cracks then extended downwards into diagonal shear cracks. Thus, with greater angle (60°) to vertical axis compared to standard 45° assumption in specification, shear resistance was reduced greatly, because of smaller concrete area and less hoops to resist shear. As a result, severe shear failure occurred to the range below the just point of the upper cut-off position.