중심축하중을 받는 고강도 철근콘크리트 기둥의 내력평가

Abstract

As the social demand is increasing in high-rise building, high-strength concrete(HSC) is issued. HSC has a lot of merits in strength. But, HSC shows brittle failure mode which has to be enhanced in ductility. So, the ductility can be improved by confinement of transverse tie, which is affected by amount, spacing, strength and configuration of lateral reinforcement and compressive strength of concrete. More experimental results in wide range of test parameters for HSC columns have to be accumulated to evaluate performance of HSC columns. Furthermore, the HSC column is overestimated as a current design code is almost based on the test results of normal strength concrete(NSC). Thus, code provisions for both design of HSC columns and confinement effect of HSC columns are demanded. An experimental study was conducted to investigate the behavior of reinforced concrete columns confined with various configuration of reinforcement. A total of 30 specimens were tested under monotonically increasing concentric compression. The test parameters included were the volumetric ratio of transverse reinforcement(ph = 0.49~2.65), tie configuration(S-type, SO-type, SR-type) and concrete compressive strength (23.4, 43.7, 70.3MPa). Test results indicate that behavior of reinforced concrete columns is influenced on the tie configuration and concrete compressive strength with almost equal volumetric ratio of transverse reinforcement and approximately equal tie spacing, and on the volumetric ratio of transverse reinforcement.