Confining reinforcement for high strength concrete columns.
Date of Issue2004
School of Civil and Environmental Engineering
A comprehensive parametric study of reinforced high-strength concrete (HSC) columns is undertaken to verify the current ACI 318 and NZS 3101 code provisions of confining reinforcement in the potential plastic hinge regions of HSC columns. A full range of parameters that have significant influences on the available strength and curvature ductility factor in the potential plastic hinges of the columns during cyclic flexure are examined. These include the concrete compressive strength fc′ , the axial load level Pe/fc′ Ag, the yield strength of transverse reinforcement fyh, the volume ratio of the transverse reinforcement, the area ratio of the longitudinal reinforcement to the gross section area ρt, and the ratio of Ag/Ac. Previously derived stress-strain relationships for compressed HSC confined by various quantities, yield strengths, and arrangements of transverse reinforcement are used in cyclic moment-curvature analyses of a range of reinforced HSC columns to derive design equations. The proposed design equations are able to determine the quantities of transverse reinforcement required for the specified curvature ductility demands of HSC columns. The accuracy of the proposed design equations was checked by comparing with experimental data reported in previous literature, and a satisfactory correlation was found.
ACI structural journal
© 2004 American Concrete Institute. This paper was published in ACI structural journal and is made available as an electronic reprint (preprint) with permission of American Concrete Institute. The paper can be found at the following official URL: [http://www.concrete.org/PUBS/JOURNALS/OLJDetails.asp?Home=SJ&ID=13091]. One print or electronic copy may be made for personal use only. Systematic or multiple reproduction, distribution to multiple locations via electronic or other means, duplication of any material in this paper for a fee or for commercial purposes, or modification of the content of the paper is prohibited and is subject to penalties under law.