Title:
Curvature Ductility of RC Beams Under Low and High Strain Rates
Author(s):
Mohammad S. Al-Haddad
Publication:
Structural Journal
Volume:
92
Issue:
5
Appears on pages(s):
526-534
Keywords:
beams (supports); building codes; concretes; ductility; earthquake resistant structures; moment-curvature relationship; reinforced concrete; reinforcing steels; strain hardening; stress-strain relationships; structural design; Structural Research
DOI:
10.14359/903
Date:
11/1/1995
Abstract:
The paper presents a parametric study of the curvature ductility capacity of reinforced concrete (RC) sections. The study considers the actual properties of reinforcing steel under both low and high strain rates of loading. It employs the mean value of the yield strength of reinforcing steel rather than the code-specified value for the best estimate of the ductility capacity of a RC section. The maximum value of tension steel ratio permissible to insure a specified ductility for singly and doubly reinforced sections is calculated under low and high strain rates of loading. The ductility capacities of the sections reinforced by the maximum longitudinal steel ratio permitted by the ACI Code for conventional and seismic design and for moment redistribution also are calculated. The results indicate that using the code-specified yield strength of the reinforcing steel leads to an overestimation of the ductility capacity of RC sections. ACI provisions of limiting the maximum longitudinal steel ratios insure sufficient ductility only for maximum ratio allowed for negative moment redistribution, but not for those specified for conventional and seismic designs.