what are precast concrete panels?
Prefabricated panels made of concrete or reinforced concrete are installed on the surface of the structure to cast the form without removing the template.
Prefabricated buildings (fields) or construction sites are made of reinforced concrete slab-form members for construction and assembly, referred to as wall panels or wall panels. The use of prefabricated concrete wall panels for the construction of prefabricated large-scale buildings can increase the degree of industrialized and mechanized construction, reduce on-site wet operations, save on-site labor, overcome seasonal effects, and shorten the construction period.
Classification According to the use of functions, it is divided into two categories: interior wall panels and exterior wall panels.
1 Interior wall board.
There are three kinds of horizontal wall panels, vertical wall panels and partition boards. The horizontal wall panels and vertical wall panels are load-bearing wall panels, and the partition wall boards are non-load-bearing wall panels. The interior wall panels should have the function of sound insulation and fire prevention. Interior wall panels are generally made from a single material (ordinary concrete, Portland concrete, or lightweight aggregate concrete), both solid and hollow.
2 exterior wall panels.
There are three kinds of facade panels, gable panels and curtain panels. The front external wall panels are self-supporting wall panels, and the gable panels and concrete wall panels are load-bearing wall panels. In addition to the sound insulation and fire prevention functions, the exterior wall panels should also have the functions of heat insulation, impermeability, freeze-thaw resistance, and anti-carbonation, and meet the requirements of architectural art decoration. The exterior wall panels can be made of light aggregate materials. Into, it can also be made of composite materials (structure layer, insulation layer and finish layer).
The production process can be used to process precast concrete wallboards in already-manufactured molds, which can be divided into cleaning templates, coating separators, in-mold reinforcements, concrete injection, vibration molding, maintenance, mold removal, inspection, product stacking and transportation, etc. Process. There are two methods: flat die production and vertical die production. According to the production process, it can be divided into four types: pedestal method, flat-mold flow method, flat-mode transport flow method, and grouped vertical model or paired vertical model method.
1. pedestal law.
Wallboard is shaped and maintained at a fixed location. All materials and equipment needed for the reinforcement, molding, curing, and removal of the mold are supplied to the wall molding section.
2. flat die flow method.
Wallboard is manufactured at several stations. After one or several processes are completed at one station, the wallboard is transported to the next station by means of lifting and transport equipment. Since there is no fixed residence time for each process, there is no fixed production cycle.
3 flat mode transmission water method.
The production process is divided into a number of processes, each of which is performed sequentially on a fixed station on the production line, and the processed wall plates are sequentially moved forward on the production line in accordance with a certain period of time.
4 sets of vertical mold or paired vertical mold method. Wallboards are produced in groups or pairs in vertical positions. The thermal curing is performed by means of vibration molding through an out-of-mold apparatus and thermal passage through the cavity. This method requires a short time, small footprint and high production efficiency, but it can only produce wall panels of a single material.
The exterior wall veneer technology can be divided into three types: decorative concrete, finish finish and finish finish.
1 decorative concrete.
The concrete exterior wall board is poured into a surface layer with various modeling lines and embossed patterns, or the demoulding surface is subjected to a specific treatment to prepare a decorative surface layer. From the method, it can be divided into two types of natural concrete finishes and secondary post-processing finishes. No need to make another finish.
2 Finish the finishing layer in the pouring.
The decorative layer is treated with special decoration before or after the concrete is poured or poured, and the prefabrication process is performed at the same time, so that the two are integrated into one.
3 Post-done finishing layer. Made of concrete exterior wall panels after the surface finish layer.
Looking back to China Since the first prefabricated concrete wallboard house was built in Beijing in 1958, the prefabricated concrete wallboard industry has developed rapidly. The use of prefabricated concrete wall panels to construct fully assembled and assembled monolithic buildings has become one of the ways for China to develop industrialized buildings. With the continuous improvement of the level of industrialization of the building, the exterior wall panel finishes should use the process of decorating the concrete or finishing the finish in the pouring process to speed up the project.