Optimal design for continuous composite slabs via metaheuristic algorithms

With the increase in greenhouse gas emissions from the construction sector, pursuing more sustainable solutions has become essential. The use of composite steel-concrete slabs can considerably reduce environmental impacts due to their rapid construction and the elimination of the need for shoring. This study aims to present the optimization problem formulation for composite steel-concrete slabs, considering continuity between slabs and the addition of positive and negative reinforcement. The design constraints adhered to the provisions of Brazilian standards for composite steel and concrete structures, while Particle Swarm Optimization and Grey Wolf Optimization algorithms were employed to solve the optimization problem. A comparative analysis was conducted with solutions provided by a formwork manufacturer to assess the effectiveness of the proposed solutions and the gains achieved through the application of the formulation. The optimization algorithms yielded similar optimal solutions in most analyses, with a slight advantage for Grey Wolf Optimization in cases where distinct solutions were obtained. The manufacturer's solutions exhibited a total CO2 emission up to 54% higher than the optimal solutions. The constraints governing the optimization problem were the formation of a plastic hinge due to a negative bending moment and failure due to longitudinal shear.