(1) Inspection of BWh's prefabricated components factory. BWh factory is a prefabrication factory which produces double skin wallboard, laminated slab and prestressed hollow slab in two workshops.

The prestressed component production line is located in a 100m long workshop, with three long line stands arranged side by side. One end is fixed and the other end is tensioned. The tensioning equipment is located in the concrete structure stand below the ground at the tensioning end. The production process of hollow slab (width about 1200mm) involves three main kinds of equipment: stretching machine, concrete forming machine and hollow slab cutting machine with mould cleaning function and prestressed reinforcement arrangement in the return.

(2) Investigation of the prefabricated components factory of leckenhausen company in Germany. Lekenhausen factory in Germany is a prefabrication factory which adopts the production line and automation equipment of anfman company. In addition to the main double skin wallboards and laminated boards, the prefabrication plant also has balcony boards, stair boards, solid wallboards of different sizes, as well as other boards and wall components.