Title:
Ductility of Doubly Reinforced Concrete Beam Sections
Author(s):
R. Park and Dai Ruitong
Publication:
Structural Journal
Volume:
85
Issue:
2
Appears on pages(s):
217-225
Keywords:
beams (supports); building codes; compression; ductility; earthquake resistant structures; moment-curvature relationship; reinforced concrete; reinforcing steels; strength; structural analysis; structural design; Structural Research
DOI:
10.14359/2760
Date:
3/1/1988
Abstract:
The available ductility of doubly reinforced concrete beam sections with a range of tension and compression steel ratios and strengths of steel and concrete are derived. The concrete is treated as unconfined. Comparisons are made of the available curvature ductility factors of rectangular sections containing the longitudinal steel ratios permitted by the provision of the design codes of the American Concrete Institute and New Zealand. The seismic design provisions of those codes for the longitudinal steel ratios in the potential plastic hinge region of beams are shown to result in a wide range of available curvature ductilities. It is concluded that the maximum tension steel ratios currently permitted for seismic design are too high, particularly for high-strength steel reinforcement. Recommendations are made for tension steel ratios to be used in design.