Optimum reinforcement and sizing of concrete cross sections subjected to flexural and axil loading

Abstract

 Although the cross-section optimization problem has been 
sufficiently studied in the past, a disadvantage persists 
regarding the programming complexity, with the need to use 
methods which are not straightforward for the structural 
engineer in his/her routine work and require excessive 
computing time.
This contribution aims not so much as to obtain the 
dimensions of the section and the required reinforcement, 
which have already been solved, but to provide an automated 
design procedure for calculating the optimum dimensions 
and reinforcement. A simple optimization method has been 
programmed in a MATLAB® routine that is attached in the 
Appendix of this paper. Conventional-strength or high-strength 
concrete may be chosen, the minimum reinforcement area may 
be considered selecting the ACI 318 or Eurocode 2 standards, 
and the neutral axis depth may be constrained in order to 
guarantee a certain cross-sectional ductility.
Therefore, the interest of the proposal is focused on providing 
an automated procedure for optimizing the dimensions and 
reinforcement of a concrete cross-section, together with the 
corresponding calculation routine, in which the structural 
engineer may include certain design conditions.
Three examples are presented and comparisons between the 
results from different methods and standards are drawn.