고강도 철근콘크리트 띠철근 기둥의 구속효과

Abstract

An experimental study was conducted to investigate the effectiveness of transverse reinforcement in reinforced concrete tied columns subjected to monotonically increasing axial compression. Eighteen large-scale columns (260x260x1200 mm) were tested. Effects of main variables such as the concrete compressive strength, the tie configuration, the transverse reinforcement ratio, the tie spacing, and the spalling of the concrete cover were considered High-strength concrete columns under concentric axial loads show extremely brittle behavior unless the columns are confined with transverse reinforcement that can provide sufficiently high lateral confinement pressure. There is a consistent decrease in deformability of column specimen with increasing concrete strength. Test results were compared with the previous confinement model such as modified Kent-Park, Sheikh-Uzumeri, Mander, and Saatcioglu-Razvi model. The comparison indicates that many previous models for confined concrete overestimate or underestimate the ductility of confined concrete.