Substituição de pontes de madeira por pontes de concreto armado: dimensionamento de longarina e aplicação de normas ABNT

Abstract

Bridges are essential for territorial integration and the transportation of goods, especially in regions with limited road infrastructure. In the state of Mato Grosso, the predominance of timber bridges compromises both safety and logistical efficiency. In this context, reinforced concrete emerges as a more durable and suitable alternative. This study presents the design of a reinforced concrete bridge girder as a solution for replacing timber bridges on rural roads. Addressing the accelerated degradation of wooden structures, the use of concrete girders was proposed to ensure greater durability and safety. The objective was to develop a comprehensive calculation procedure based on ABNT NBR 6118 (2024) and ABNT NBR 7187 (2021). The methodology involved identifying permanent and variable loads, applying an impact factor, modeling in Ftool, and producing technical drawings in AutoCAD. The results indicated a required longitudinal reinforcement area of 96.48 cm² (12 bars of Ø 32 mm), with stirrups of Ø 6.3 mm spaced at 9 cm and 30 cm, meeting ultimate and fatigue limit state criteria. It is concluded that the proposed procedure is replicable and provides technical reliability for similar projects.