What are the main applications of I-beams in construction?

I-beams form the skeleton of high-rise buildings (columns, floor joists), with W-shapes preferred for their load-bearing efficiency. In bridges, they span gaps as girders, supporting roadways over rivers or valleys. Industrial facilities use I-beams for crane rails and mezzanine floors, while warehouses employ them in racking systems. Their high strength-to-weight ratio reduces material use-e.g., a 10-story building uses 30% less steel with I-beams than with square bars. Galvanized I-beams are used outdoors (e.g., stadiums) to resist corrosion, while fire-resistant coated I-beams protect against high temperatures in commercial buildings.