What materials are in a Double-decked briges?

Double-decked bridges typically consist of various materials including steel, concrete, and sometimes reinforced composites. The superstructure often utilizes steel beams or trusses for strength, while concrete is commonly used for the deck and supports. Additional materials may include asphalt for road surfaces and protective coatings to prevent corrosion. The choice of materials depends on factors like load requirements, environmental conditions, and design specifications.