|
Title |
Repeated Loading Test of Shear-Critical Reinforced Concrete Beams with Headed Shear Reinforcement
|
|
Keywords |
헤디드 바 ; 전단 ; 정착 ; 다발 스터럽 ; 반복하중 |
|
Abstract |
The repeated loading responses of four shear-critical reinforced concrete beams, with two different shear span-to-depth ratios, were studied. One series of beams was reinforced using pairs of bundled stirrups with 9O' standard hooks, having free end extensions of 6db. The companion beams contained shear reinforcement made with larger diameter headed bars anchored with 5Omm diameter circular heads. A single headed bar had the same area as a pair of bundled stirrups and hence the two series were comparable. The test results indicate that beams containing headed bar stirrups have a superior performance to companion beams containing bundled standard strrups, with improved ductility, larger energy absorption and enhanced post-peak load carrying capability. Due to splitting of the concrete cover and local crushing, the hooks of the standard stirrups opened, resulting in loss of anchorage. In contrast, the headed bar stirrups did not lose their anchorage and hence were able to develop strain hardening and also served to delay buckling of the flexural compression steel. Excellent load-deflection predictions were obtained by reducing the tension stiffening to account for repeated load effects.
|