### Minimum Cost for Reinforced Concrete Rectangular Beams with Parabolic Haunches

#### Abstract

Objective of this research is to present a mathematical model for optimal design of rectangular cross-section beams with parabolic haunches under the criterion of minimum cost taking into account the concrete cost and reinforcing steel cost, and considering the equations of the code (ACI 318S-19). This model presents the equations for two types of loads: uniformly distributed load and concentrated load located anywhere on the beam. Two examples have been developed by the proposed model for both cases. The results show that the prismatic beams for the two cases have a total cost, a total volume and total weight greater with respect to the non-prismatic beams. Then, the non-prismatic beams are more economic, have less volume and also have less weight with respect to prismatic beams.

#### Keywords

Optimal design, parabolic haunches, minimum cost, rectangular cross-section beams, uniformly distributed load and concentrated load