Estudo comparativo de lajes mistas visando um orçamento final mais vantajoso

Abstract

This paper presents a comparative analysis of different configurations of composite steel concrete slabs, aiming to identify the most cost effective structural solution from a technical and economic perspective. The research focused on alternatives using MF75 steel-deck profiles, varying the thickness of the metal sheets, the total slab depth, and the need for additional reinforcement, while always meeting the required fire-resistance and structural-performance standards. To achieve this, three distinct design scenarios were modeled, followed by a detailed material takeoff and cost estimates based on standardized inputs from the SINAPI, TCPO, and SBC cost databases. The analyses considered a 120 square meter slab with a three-meter span, designed to support the live loads of a commercial building. The first scenario, featuring a thinner metal sheet and a thicker concrete topping, resulted in an intermediate cost per square meter. The second, with a thicker sheet and a smaller concrete volume, produced the highest cost per square meter. The third scenario, which incorporated additional reinforcement for both positive and negative bending moments, achieved the lowest total cost per square meter while maintaining excellent technical performance. The results show that selecting the optimal composite slab configuration requires weighing not only technical and code requirements but also the balance between material consumption and overall cost to ensure safe and efficient structural performance.