14-04-2017, 05:50 PM
17-04-2017, 04:06 PM
Prefabrication is the practice of assembling components of a structure in a factory or other manufacturing site and transporting complete assemblies or subassemblies to the construction site where the structure is to be located. The term is used to distinguish this process from the more conventional construction practice of transporting the basic materials to the construction site where the entire assembly is carried out.
The term prefabrication also applies to the manufacture of elements other than structures at a fixed site. It is often used when manufacturing a section of a machine or any moving structure moves from the main manufacturing site to another location, and the section is supplied assembled and ready to fit. Generally, it is not used to refer to electrical or electronic components of a machine, or mechanical parts such as pumps, gearboxes and compressors that are normally supplied as separate elements, but to sections of the machine body that in the past were made with The whole machine. The prefabricated parts of the machine body may be referred to as "subassemblies" to distinguish them from the other components.
Process and theory
An example of housing construction illustrates the prefabrication process. The conventional method of building a house is to transport bricks, wood, cement, sand, steel and building aggregates, etc. To the site, and build the house on site from these materials. In prefabricated construction, only foundations are constructed in this way, while sections of walls, floors and ceilings are prefabricated (assembled) in a factory (possibly with window frames and doors included), transported to the site, raised in their Place by a crane and screwed.
Prefabrication is used in the manufacture of ships, aircraft and all types of vehicles and machines, where the sections previously assembled at the final point of manufacture are assembled in another place before being delivered for final assembly.
The theory behind the method is that time and cost are saved if similar construction tasks can be grouped together, and assembly line techniques can be employed in prefabrication in a place where skilled labour exists, while congestion at the site Of assembly, which is wasting time, can be reduced. The method finds application particularly where the structure is composed of units or repetitive forms, or where multiple copies of the same basic structure are being constructed. Prefabrication avoids the need to transport so many skilled workers to the construction site, and other restrictive conditions such as lack of power, lack of water, exposure to adverse weather conditions or a hazardous environment are avoided. Against these advantages we must weigh the cost of transporting prefabricated sections and lifting them in position as they will normally be larger, more fragile and more difficult to handle than the materials and components from which they are made.
The term prefabrication also applies to the manufacture of elements other than structures at a fixed site. It is often used when manufacturing a section of a machine or any moving structure moves from the main manufacturing site to another location, and the section is supplied assembled and ready to fit. Generally, it is not used to refer to electrical or electronic components of a machine, or mechanical parts such as pumps, gearboxes and compressors that are normally supplied as separate elements, but to sections of the machine body that in the past were made with The whole machine. The prefabricated parts of the machine body may be referred to as "subassemblies" to distinguish them from the other components.
Process and theory
An example of housing construction illustrates the prefabrication process. The conventional method of building a house is to transport bricks, wood, cement, sand, steel and building aggregates, etc. To the site, and build the house on site from these materials. In prefabricated construction, only foundations are constructed in this way, while sections of walls, floors and ceilings are prefabricated (assembled) in a factory (possibly with window frames and doors included), transported to the site, raised in their Place by a crane and screwed.
Prefabrication is used in the manufacture of ships, aircraft and all types of vehicles and machines, where the sections previously assembled at the final point of manufacture are assembled in another place before being delivered for final assembly.
The theory behind the method is that time and cost are saved if similar construction tasks can be grouped together, and assembly line techniques can be employed in prefabrication in a place where skilled labour exists, while congestion at the site Of assembly, which is wasting time, can be reduced. The method finds application particularly where the structure is composed of units or repetitive forms, or where multiple copies of the same basic structure are being constructed. Prefabrication avoids the need to transport so many skilled workers to the construction site, and other restrictive conditions such as lack of power, lack of water, exposure to adverse weather conditions or a hazardous environment are avoided. Against these advantages we must weigh the cost of transporting prefabricated sections and lifting them in position as they will normally be larger, more fragile and more difficult to handle than the materials and components from which they are made.