The picture does not show the information completely. It should be displayed as 2C 18+ 1C 16, 2C 16+2C 14, 3C 16. It means two 18 plus 16 tertiary steels, two 1 6 plus two 14 tertiary steels and three 16 tertiary steels.
According to the positions marked on the beam 2C 18+ 1C 16, 2C 16+2C 14, 3C 16, it can be seen that these are all in-situ marks of the beam. It can be understood as local detailed annotation.
Steel structure
It is a structure composed of steel and one of the main types of building structures. The structure is mainly composed of steel beams, steel columns, steel trusses and other components made of section steel and steel plates. The rust removal and rust prevention processes such as silanization, pure manganese phosphating, washing and drying, and zinc plating are adopted. Welding, bolts or rivets are usually used to connect components or parts. Because of its light weight and simple construction, it is widely used in large factories, stadiums, super high-rise buildings and other fields. Steel structures rust easily. In general, steel structures should be derusted, galvanized or painted, and maintained regularly.