Title: Behavior of Square Columns with Interlocking Pattern Ties under Axial Compression
Author(s): Vemuri V. Rangarao, Kolluru V. L. Subramaniam, and S. Suriya Prakash
Publication: Structural Journal
Appears on pages(s): 209-222
Keywords: columns; confinement; ductility; interlocked; ties; uniaxial compression
An innovative transverse reinforcement (TR) system for square reinforced concrete (RC) columns is proposed in this study. It consists of an interlocking pattern (SIP) formed by inclined ties for improving the confinement of the concrete core in the column. Specific improvements of the SIP system over the conventional ties (SC) include more uniform confinement along the axis of the column and better lateral restraint to longitudinal bars. The development and assembly of the SIP system are presented. The performance of short RC columns with an identical volumetric ratio of SC and SIP ties is investigated experimentally. Columns with the SIP tie system exhibit improvements in load capacity and ductility. In comparison with SC ties, higher deformations and larger strain energy are measured from the columns reinforced with SIP ties. The columns with SIP ties had significantly smaller visible damage when
compared to the columns with SC ties. Experimentally measured axial strains in concrete and longitudinal reinforcing bars are also lower in the columns with SIP ties. A numerical evaluation indicates a higher average effective confinement pressure on concrete and lower damage in the cover for columns with the SIP system.