E04B—GENERAL BUILDING CONSTRUCTIONS; WALLS, e.g. PARTITIONS; ROOFS; FLOORS; CEILINGS; INSULATION OR OTHER PROTECTION OF BUILDINGS
E04B1/00—Constructions in general; Structures which are not restricted either to walls, e.g. partitions, or floors or ceilings or roofs
E04B1/18—Structures comprising elongated load-supporting parts, e.g. columns, girders, skeletons
E04B1/30—Structures comprising elongated load-supporting parts, e.g. columns, girders, skeletons the supporting parts being composed of two or more materials; Composite steel and concrete constructions