Reinforced concrete slab-type members for building assembly, referred to as wall panels or siding, are processed in prefabricated plants (fields) or construction sites. The use of precast concrete wall panels to construct prefabricated slab construction can improve the degree of industrialization and mechanization, reduce on-site wet work, save on-site labor, overcome seasonal impacts, and shorten the construction period.
Classification According to the function of use, it is divided into two categories: interior wall panel and exterior wall panel.
1 interior wall panel. There are three kinds of horizontal wall panels, vertical wall panels and partition wall panels. The horizontal wall panel and the vertical wall panel are load-bearing wall panels, and the partition wall panels are non-load-bearing wall panels. The interior wall panel should have the function of sound insulation and fire prevention. Interior wall panels are generally made of a single material (common concrete, Portland concrete or light aggregate concrete), both solid and hollow.
2 exterior wall panels. There are three kinds of front wall panels, gable panels and wall panels. The front exterior wall panel is a self-supporting wall panel, and the gable panel and the wall panel are load-bearing wall panels. In addition to the function of sound insulation and fire prevention, the exterior wall board should also have the functions of heat insulation, impermeability, freeze-thaw resistance, anti-carbonization and meet the requirements of architectural art decoration. The outer wall board can be made of light aggregate material. It can also be made of composite materials (structural layer, thermal insulation layer and veneer layer).
The production process is to process precast concrete walls in the prepared mold, which can be divided into cleaning template, coating release agent, in-mold reinforcement, pouring concrete, vibration molding, curing, demoulding, inspection, finished product stacking and transportation, etc. Process. The method has two types of flat mold production and vertical mold production. According to the production process, it is divided into four types: pedestal method, flat-die unit flow method, flat-die transfer flow method, and grouped vertical mold or paired vertical mold method.
1 seat method. Wall panels are formed and cured in a fixed location. All materials and equipment required for the process of reinforcement, forming, curing and demoulding are supplied to the wall forming.
2 flat mold unit flow method. Wall panels are manufactured at several stations. When one or more processes are completed at one station, the wallboard is transported to the next station using lifting transport equipment. Since there is no fixed dwell time for each process, there is no fixed production tact.
3 flat die transfer flow method. The production process is divided into several processes, each of which is sequentially performed on a fixed station on the production line, and the processed wallboard is sequentially moved forward on the production line at a certain time tempo.
4 group vertical mold or paired vertical mold method. The wall panels are produced in groups or in pairs in a vertical position. The heat is cured by the external molding equipment and the cavity is heated. This method requires a short time, a small footprint, and high production efficiency, but can only produce wallboard of a single material.
The exterior wall veneering process can be divided into decorative concrete, finished finishing layer and post-finishing layer.
1 decorative concrete. The concrete outer wall panel is cast into a surface layer with various molding lines and embossed patterns or the surface after demolding is subjected to a specific treatment to form a decorative surface layer. From the method, it is divided into two kinds of natural concrete finishes and secondary post-finish finishes, and no additional finish layer is needed.
2 Finishing finish in the filling. The decorative layer of special decorative treatment before or after concrete filling is carried out simultaneously with the prefabrication process, so that the two are combined into one.
After 3, do the finishing layer. After the concrete siding is made, the surface finish layer is made.
Outlook Since the construction of the first concrete wall panels house in Beijing in 1958, the precast concrete wallboard industry has developed rapidly. The use of precast concrete wall panels to construct fully assembled and assembled monolithic slabs has become one of the ways for China to develop into industrialization. As the level of industrialization of buildings continues to increase, exterior wall panel finishes should be decorated with concrete or filled finishes to speed up the project.