E04B—GENERAL BUILDING CONSTRUCTIONS; WALLS, e.g. PARTITIONS; ROOFS; FLOORS; CEILINGS; INSULATION OR OTHER PROTECTION OF BUILDINGS
E04B2/00—Walls, e.g. partitions, for buildings; Wall construction with regard to insulation; Connections specially adapted to walls
E04B2/02—Walls, e.g. partitions, for buildings; Wall construction with regard to insulation; Connections specially adapted to walls built-up from layers of building elements
E04B2/42—Walls having cavities between, as well as in, the elements; Walls of elements each consisting of two or more parts, kept in distance by means of spacers, at least one of the parts having cavities
E—FIXED CONSTRUCTIONS
E04—BUILDING
E04C—STRUCTURAL ELEMENTS; BUILDING MATERIALS
E04C3/00—Structural elongated elements designed for load-supporting
E04C3/02—Joists; Girders, trusses, or trusslike structures, e.g. prefabricated; Lintels; Transoms; Braces
E04C3/20—Joists; Girders, trusses, or trusslike structures, e.g. prefabricated; Lintels; Transoms; Braces of concrete or other stone-like material, e.g. with reinforcements or tensioning members
E04C3/22—Joists; Girders, trusses, or trusslike structures, e.g. prefabricated; Lintels; Transoms; Braces of concrete or other stone-like material, e.g. with reinforcements or tensioning members built-up by elements jointed in line