Abstract
An exact analysis is carried out utilizing the stress-strain curve for concrete confined by circular hoops and a typical idealized stress-strain curve for steel to develop the moment-curvature relationship for reinforced concrete (RC) circular column sections. Based on that, the flexural rigidity EI of the section is determined at the yield curvature. A computer program is written in Fortran 77 to handle the required computations. The influence of material properties, the effect of steel ratios and the impact of axial loads on the EI estimation were investigated. This study leads to the development of a new equation to estimate the flexural rigidity EI of RC circular columns in which these factors were considered. It is shown that the new equation stems from the actual behaviour of the column. Therefore, it is recommended for general use in the design of slender columns.
Resume
On a effectué une analyse précise en utilisant la courbe contrainte/déformation de béton fretté et une courbe typique idéalisée contrainte/déformation pour l'acier afin de développer la relation courbe/moment de sections de piliers circulaires en béton armé. Sur cette base, on a déterminé la rigidité en flexion EI de la section au point d'inflexion de la courbe. On a établi un programme Fortran 77 pour effectuer les calculs nécessaires. On a examiné l'influence des propriétés du matériau, l'effet des pourcentages d'acier et l'impact des charges axiales sur l'évaluation de la rigidité en flexion. Cette étude conduit à mettre au point une nouvelle équation pour l'évaluation de la rigidité en flexion EI de piliers circulaires en béton armé pour lesquels on considère ces facteurs. On montre que la nouvelle équation est tirée du comportement réel du pilier. On la recommande donc pour une utilisation courante dans le calcul de piliers minces.
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References
ACI Committee 318, ‘Building Code Requirements for Reinforced Concrete (ACI 318-89) and Commentary-(ACI 318R-89)’ (American Concrete Institute, Detroit, 1989).
MacGregor, J. G., Breen, J. E. and Pfrang, E. O., ‘Design of slender concrete columns’,ACI J., Proc. 67 (1970) 6–28.
MacGregor, J. G., Oelhafen, U. H. and Hage, S. E., ‘A Re-Examination of the EI Value for Slender Columns. Reinforced Concrete Columns’: SP-50 (American Concrete Institute, Detroit, 1975).
Ehsani, M. R. and Alameddine, F., ‘Refined stiffness of slender circular reinforced concrete columns’,ACI J., Proc. 84 (1987) 419–427.
Mirza, S. A., ‘Probability-based strength criterion for, reinforced concrete slender columns’,Ibid,84 (1987) 459–466.
Mirza, S. A. and MacGregor, J. G., ‘Slenderness and strength reliability of reinforced concrete columns’,Ibid 86 (1989) 428–438.
Mirza, S. A., ‘Flexural stiffness of rectangular reinforced concrete columns’,Ibid 87 (1990) 425–435.
Zeng, J. M., Duan, L., Wang, F. M. and Chen, W. F., ‘Flexural rigidity of reinforced concrete columns’,Ibid 89 (1992) 150–158.
Kent, D. C. and Park, P., ‘Flexural members with confined concrete’,J. Struct. Div. ASCE,97, ST7 (1971) 1969–1990.
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Resheidat, M., Ghanma, M., Numayr, K. et al. Improved ‘EI’ estimation for reinforced concrete circular columns. Materials and Structures 27, 515–526 (1994). https://doi.org/10.1007/BF02473212
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DOI: https://doi.org/10.1007/BF02473212