OPTIMUM DESIGN OF PRESTRESSED HOLLOW CORE SLAB VIA GENETIC ALGORITHM

Resumo

The search for more efficient solutions in reinforced concrete buildings is necessary, in view of the industrialization process of the civil construction sector. Within this scenario, the use of hollow core slabs becomes an interesting process, in view of the speed of execution and the possibility of overcoming larger spans. This paper presents a formulation for the design optimization problem of prestressed reinforced concrete hollow core slabs. The procedure was implemented with Matlab, following design guidelines from the ABNT (Brazilian Association of Technical Standards), according to the standards NBR 6118:2014, NBR 14861:2011 and NBR 9062:2017 and using the guide toolbox to build a Graphical interface. The optimization problem was solved using the genetic algorithm feature native to Matlab, considering the minimization of manufacturing cost of the slab as the objective function. Numerical examples show improvements of the final design, with smaller free spans presenting the serviceability limit state (SLS) as the preponderant design restriction, while the design of larger spans is governed by the tensile forces on the upper surface of the slab during prestressing.