What are types of girders?

Girders are structural elements that support loads in bridges, buildings, and other constructions. Common types of girders include I-beams, which have a cross-section resembling the letter "I," providing high strength with less material; box girders, which are hollow and offer good resistance to torsion; and plate girders, constructed from steel plates welded together, allowing for custom sizing and strength. Additionally, there are curved girders used in arch bridges and composite girders that combine materials like steel and concrete for enhanced performance.