The Missing Effects Of Yield strength And Arrangement Of Transverse Rebars On The Modeling Parameters Of RC Columns In Current Standards

Document Type : Research Article

Authors

Abstract

The nonlinear force-displacement curve of RC columns are presented in the current standards for seismic rehabilitation of existing buildings (such as ASCE41) by two displacement-based values of “a” and “b” that correspond to the loss of lateral and axial capacities, respectively. The ASCE41 presents the values of these two parameters as a function of the volumetric ratio of transverse reinforcement. A confinement index is proposed in this paper that accounts for the yield strength and arrangement of the transverse reinforcements as well. This index was used to predict the parameters “a” of 38 tested RC columns and the parameters “b” of 13 other columns. A table is proposed that gives the values of these two parameters based on the values of the proposed confinement index of the columns. It is shown that the proposed confinement index and table predicts more accurate values of the parameters “a” and “b”. Based on the results, maximum difference ratio to experimental values is reduced from 4.7 to 3.6 in comparison with those of update to ASCE41-06 while satisfying its specifications and regulations.

Keywords

References

[1]Elwood, K. J. et al. (2009), Update to ASCE/SEI 41 Concrete Provisions., Peer report.
[2]Sheikh, S. A. and Uzumeri, S. M. (1982). Analytical Model For Concrete Confinement In Tied Columns.,ASCE Journal Of Structural Engineering 108:5, 2703–2723.
[3]Mander, B. J., Priestley J. N. M. And Park R. (1988). Theoretical Stress-Strain Model For Confined Concrete.,ASCE Journal Of Structural Engineering, 144:8, 1804-1826.
[4]Eurocode 8 (1995), Design Provisions for Earthquake Resistance of Structures., commission of the European communities.
[5]Muguruma, H., Watanabe, F., and Komuro, T.,(1989). Applicability of High Strength Concrete to Reinforced Concrete Ductile Column., Transactions of the Japan Concrete Institute, 11, 309-316.
[6]FEMA 273, (1997), NEHRP guidelines for the Seismic rehabilitation of buildings, Federal emergency management agency.
[7]FEMA 356, (2000), Prestandard and commentary for the Seismic rehabilitation of buildings, Federal emergency management agency.
[8]ASCE/SEI 41-06, (2007), Seismic rehabilitation of existing buildings., American Society of Civil Engineers.
Amirkabir Journal of Civil Engineering
Volume 44, Issue 2 - Serial Number 2
February 2012
Pages 83-93

Files

Share

How to cite

Statistics