2.
Wood formwork is used for column formwork blanking, which has serious waste of resources, poor recycling performance, low strength, easy pulp wrapping, formwork expansion, difficult to control, and complex operation of workers; 3.
Compared with the traditional cast-in-situ construction mode, the construction characteristics of prefabricated buildings determine that the consumption of lifting machinery is relatively high and the labor consumption is relatively small.
When the concrete is poured on site, it needs to be sent to the site by the commercial mixing station for pouring.
Among them, the use cost of machines and tools on the construction site is higher, mainly due to the higher accuracy requirements of the assembly construction for the hoisting machinery, and the use intensity and number of shifts of this kind of hoisting machinery are higher than those of the general tower crane turnover equipment in traditional buildings.
1.
Reasons for the increment of prefabricated construction: the on-site construction content of prefabricated buildings is mainly the hoisting of prefabricated components.
Do not use split bolts and do not need later plugging 4 The components are fixed on site with inclined support, with high strength, high-strength grouting material is used at the connection position of the components, the grouting integrity is firm, the reinforcement is connected with sleeve, and the grouting strength is high.
This part of the cost is one of the main sources of incremental cost of component production.
Reasons for the increase of component transportation cost: the transportation cost of prefabricated components refers to various expenses incurred in the process of transporting prefabricated components from the factory to the construction site.
Labor cost: due to the flow production of prefabricated components and parts in the factory, most of the work is replaced by mechanical equipment, and the labor cost is reduced compared with the traditional construction method.
Mold cost: at present, the design standardization of some parts has not been fully realized.
If the component supply chain is perfect, the production demand of prefabrication factory is strong, and the scale effect is obvious, the unit cost of fixed assets depreciation amortized into components will be lower, which will lower the component price; On the contrary, it will push up the component price.
3.
In addition, the low reuse rate of molds, the higher the mold cost.
The use of split bolts causes holes on the wall and it is difficult to block in the later stage; 4.
This part of the cost is not available in the traditional cast-in-situ construction method.
Prefabricated component factories are generally located in the suburbs far away from the city, with low land cost and close to the sand and stone mining land.
The formwork adopts steel formwork with high strength, which can be used for many times and produced in batch, which greatly saves wood formwork resources; 3.
1.
The prefabricated structure is mainly produced in batch in the prefabrication plant, and the reinforcement binding and blanking are carried out in the factory, with concentrated human and material resources and high safety factor; 2.
This part of fixed assets will be depreciated in a certain way (if it is leasing, the rent will be included in the component production cost).
Component storage and management fee: after component prefabrication and production, a large area of stacking yard is required for storage and management.
The reason for the cost increment in the component production stage: the cost in the production stage of prefabricated components mainly includes: labor cost, material cost, mold cost, production line depreciation cost, component storage and management cost, water cost, electricity cost, etc.
The following table takes a single storey residential project with an area of 1000 M2 as an example.
1.2 the manpower is compared with 30 reinforcement workers, 3 signal workers, 10 reinforcement blanking workers, 10 formwork workers, 10 formwork blanking workers, 10 concrete pouring workers and 10 formwork removal; A total of 73 people, 15 on-site hoisting, 3 signal workers, 10 inclined support installation, 5 grouting, 2 reinforcement workers at the cast-in-situ position, 2 formwork and 3 concrete cast-in-situ; A total of 40 people compared with the traditional cast-in-situ floor and laminated floor 2.1 comparison of advantages and disadvantages of process 1 Wooden formwork is used to support the windowsill floor.
There are too many formwork materials, large amount of labor and too much material transportation; 2.
The transportation cost is mainly related to the transportation distance and transportation mode: for the transportation of prefabricated components, especially on important urban trunk roads, not only the volume size of components, but also the time period of traffic congestion should be considered.
Today, I’ll share with you a small summary of the rise in construction and installation costs compared with the traditional cast-in-place: the rising proportion of the cost of prefabricated buildings is related to the specific prefabricated design scheme, prefabrication rate and assembly rate, which can not be generalized, but the overall construction and installation cost has a growth rate of about 10-15% compared with the traditional cast-in-place.
Construction comparison and comparison of traditional cast-in-situ wall column beam and fabricated wall column beam 1.1 comparison of advantages and disadvantages of process 1 The reinforcement needs to be bound and cut on site, which is very cumbersome.
The component installation cost of the prefabricated building construction site mainly includes: component vertical transportation cost, installation labor cost, machine use cost, etc.
The construction cost of prefabricated building site is mainly composed of component installation cost, measure cost, etc.
There are a large number of workers and a long time interval, which is easy to produce construction cold joints, the concrete is solidified on site, and the strength cannot be guaranteed.
So, where is the growth of the construction and installation cost of assembly? What is the crux? The increment of construction and installation cost of prefabricated buildings is mainly reflected in three aspects: component production, component transportation, component construction and installation.
However, this may increase the transportation distance, highway charges and vehicle fuel charges, and increase the transportation cost.
There are many workers and tools, so it is inconvenient to carry upstairs and downstairs; 2.
The labor consumption in the construction process of prefabricated building site is less, but the professional and technical level of management personnel and construction personnel is relatively high, which increases the training cost of staff.
Material cost: compared with the traditional cast-in-situ construction mode, the on-site loss of material consumption is reduced and the material is saved.
Depreciation cost of production line: fixed assets such as the workshop of component factory and the production line machinery and equipment of production components have a large investment in the early stage.
The measure cost of on-site construction of prefabricated buildings is basically the same as that of traditional buildings, and the use cost of on-site formwork and scaffold will be reduced.
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The more kinds of prefabricated components are produced, the more complex the structure is, the more molds need to be used.
The splicing of the formwork is not firm and it is easy to run slurry, but the bottom of the floor slab is not smooth, there are butt joints, the camber is not easy to control, and the concrete removal after formwork pouring is laborious and manual..
