Eccentricity-Based Optimization Procedure for Strength Design of RC Sections under Compression and In-Plane Bending Moment
Publication: Journal of Structural Engineering
Volume 140, Issue 1
Abstract
The strength design of reinforced concrete (RC) rectangular sections for combined compression and in-plane bending with two levels of reinforcement is indeterminate: three unknowns are to be solved, but with only two equilibrium equations; an additional condition is necessary to solve the problem. The additional condition leads to the finding of a minimum reinforcement-concrete ratio. This paper proposes a new approach based on the equivalent eccentricity of the applied compressive load. Different domains are reported, each of which is associated with given values of eccentricity and axial load. Analytical expressions for the domain boundaries are established, and a simple procedure is described to outline the conditions corresponding to the optimal reinforcement. The main advantage of this procedure is its simplicity, which allows manual computations. Some examples employing reinforcement sizing diagrams illustrate the validity of this approach.
Get full access to this article
View all available purchase options and get full access to this article.
Acknowledgments
Part of the present work was financed by the Spanish Ministry of Education. The second author is a Spanish government Ph.D. fellow (FPU grant AP 2010-3707). This support is gratefully acknowledged.
References
Aschheim, M., Hernández-Montes, E., and Gil-Martín, L. M. (2007). “Optimal domains for strength design of rectangular sections for axial load and moment according to Eurocode 2.” Eng. Struct., 29(8), 1752–1760.
Barros, A. F. M., Barros, M. H. F. M., and Ferreira, C. C. (2012). “Optimal design of rectangular RC sections for ultimate bending strength.” Struct. Multidisciplin. Optim., 45(6), 845–860.
Barros, M. H. F. M., Martins, R. A. F., and Barros, A. F. M. (2005). “Cost optimization of singly and doubly reinforced concrete beams with EC2-2001.” Struct. Multidisciplin. Optim., 30(3), 236–242.
Camp, C. V., Pezeshk, S., and Hansson, H. (2003). “Flexural design of reinforced concrete frames using a genetic algorithm.” J. Struct. Eng., 105–115.
Comité Européen de Normalisation (CEN) Eurocode 2. (2001). “Design of concrete structures—Part 1-1: General rules and rules for buildings.” EN 1992-1-1, CEN European Committee for Standardization, Brussels.
Gil-Martín, L. M., López-Martín, D., Hernández-Montes, E., and Aschheim, M. (2012). “Dimensionamiento en rotura a flexión de secciones de hormigón armado. Un planteamiento compacto.” Informes de la Construcción, 64, 497–505.
Hernández-Montes, E., Aschheim, M., and Gil-Martín, L. M. (2004). “Impact of optimal longitudinal reinforcement on the curvature ductility capacity of reinforced concrete column sections.” Mag. Concr. Res., 56(9), 499–512.
Hernández-Montes, E., Gil-Martín, L. M., and Aschheim, M. (2005). “Design of concrete members subjected to uniaxial bending and compression using reinforcement sizing diagrams.” ACI Struct. J., 102(1), 150–158.
Hernández-Montes, E., Gil-Martín, L. M., Pasadas-Fernández, M., and Aschheim, M. (2008). “Theorem of optimal reinforcement for reinforced concrete cross sections.” Struct. Multidisciplin. Optim., 36(5), 509–521.
Lee, C., and Ahn, J. (2003). “Flexural design of reinforced concrete frames by genetic algorithm.” J. Struct. Eng., 762–774.
López-Martín, D., Gil-Martín, L. M., Hernández-Montes, E., and Aschheim, M. (2011). “Dominios de deformación referidos a la excentricidad de cálculo para el diseño óptimo de secciones rectangulares solicitadas a flexo-compresión.” 1st Intl. Cong. Mech. Models Struct. Eng., Godel Impresiones Digitales, Granada, Spain, 93–106.
Nawy, E. G. (2003). Reinforced concrete: A fundamental approach. 5th Ed., Prentice-Hall, Upper Saddle River, NJ.
Information & Authors
Information
Published In
Journal of Structural Engineering
Volume 140 • Issue 1 • January 2014
Copyright
© 2013 American Society of Civil Engineers.
History
Received: Jul 3, 2012
Accepted: Dec 17, 2012
Published online: Dec 19, 2012
Published in print: Jan 1, 2014
Discussion open until: Feb 23, 2014
Authors
Metrics & Citations
Metrics
Citations
Download citation
If you have the appropriate software installed, you can download article citation data to the citation manager of your choice. Simply select your manager software from the list below and click Download.