Otimização de lajes de concreto com nervuras pré-moldadas com armação treliçada

Abstract

Concrete slabs with lattice frames, also known as lattice slabs, are widely used in small to medium-sized structures. Adding to the trend of rationalization of civil construction, which aims to reduce expenditures and wastage, there is a need to develop optimization methods. These methods have the objective of proposing optimal solutions, that is, that they satisfy the requirements in the most economical way possible. To do so, there are models that combine certain properties of the materials and geometry of the section in order to provide a better use of these characteristics in front of the requests and, consequently, a lower final cost. The present study used the nonlinearmethod ofGeneralizedReduced Gradient (GRG), available in the Solver tool of Excel software. Slab lattices formed by two spans were analyzed, considering the connection between them as labeled, continuous or with redistribution of momentum. Also analyzed was the effect causedby the consideration of the Poisson coefficient in the concrete table created in the direction perpendicular to the lattice beams. The results obtained showed satisfactory reductions in the final costs of the square meter of latticework, with order of magnitude between 15% and 25%. Certain patterns were observed in the obtained solutions, like the reduction of the height of the concrete cover, increase in the distance between joists, among others. Therefore, from the applications carried out in this work, it is concluded that the development of optimization models of lattice slabs is feasible. In addition, consideration of the continuity between spans has generated more economical solutions. Finally, as a suggestion of future work, a more in-depth study is recommended regarding the possibility of manufacturing fillers with larger widths.