It is only that the part of the workers required for the reinforcement works, carpentry formwork and concrete pouring that were originally constructed on the site have been transferred to the precast component processing plant.

frame columns and shear walls); For the project under drawing review, it shall be adjusted that there is no vertical stress component to be submitted for review; For the projects that have passed the drawing review, it is also recommended to make design changes and cancel the use of precast form for vertical load-bearing components.

In fact, it is not necessary.

There are the following factors restricting the development of assembly-type in China: First, the assembly-type technology at home and abroad is not mature, and there are no skilled operators in this field.

At present, some local governments are pushing for precast buildings, and require how many indicators the assembly rate and prefabrication rate should reach within a few rings.

The reason is clear to everyone: at present, the connection of the vertically assembled stress system is not mature, which is mainly manifested by the lack of effective detection means for the density of the grouting material at the joint of the grout-anchor link, and the grouting quality is mixed in the market After hearing this news, the peers in the industry all agreed: A: For the cast type, I have been worried about the seismic problem.

It can not be mass produced, and the reuse rate is low, so it is impossible to reduce its marginal cost.

According to the field survey, precast buildings cost more labor hours than cast-in-place structures, and the construction period is longer.

Everyone likes good things, and everyone likes bad things just to cheat the government.

Some people think that the labor consumption of precast buildings is significantly reduced by 30%~50% compared with that of traditional cast-in-place buildings, so they draw the conclusion that the labor consumption has obvious advantages.

If the capacity of PC plant is insufficient, the construction site may have to wait in line, thus delaying the construction period.

The only advantage of precast buildings is to reduce wet operation on site, and water and electricity may not be saved.

Ha ha.

The energy consumption of on-site casting and factory prefabrication is the same! But the promotion of assembly is under the banner of energy conservation and environmental protection! However, the first problem to be solved for the structure is safety.

Only adjusting measures to local conditions and letting the market choose is the most correct path.

And these joints also affect the mechanical properties of the structure.

Secondly, there is no standardization of domestic building components, and various specifications are ever-changing, which means personalized customization.

F: The energy consumption of concrete is mainly cement.

If the quality of the cast-in-place structure is not good, it will also cause water seepage of the external wall, but after all, it is an integral cast-in-place structure, while the precast building has a large number of joints due to the assembly of PC components.

Third, due to the lack of craftsmanship, migrant workers have become accustomed to rough manufacturing, and can not adapt to and meet the precision requirements required by precast buildings.

If the inspection method can’t keep up with it, no matter how good the laboratory system is, it won’t know what it will be.

H: The people who went to the site should not be optimistic.

Fourth, the assembly building leaves a huge quality hazard, such as water seepage from the exterior wall.

If only feasibility study is done, you may only see its advantages and ignore its disadvantages.

The biggest problem of precast concrete structures is the problem of on-site inspection methods.

It was analyzed that compared with cast-in-place structure, precast buildings reduce the loss of water, electricity and formwork by 20%~40%, and precast buildings have obvious advantages in four sections and one environmental protection.

After investigation and research, the author found that precast buildings have no much advantages over cast-in-place structures.

The components and components of precast buildings can be processed in advance in the factory, but the installation of PC components costs more labor hours.

J: It feels like we are all assembling for the purpose of assembling now! In fact, the precast type of infilled wall is more reliable.

The construction industry also needs to have realistic feasibility to transform the construction and production modes, transform and upgrade.

I: The inspection of the grouting compactness may be a problem.

C: At present, it seems that on-site control is indeed a problem D.

Some people think that precast buildings use less time than traditional cast-in-place buildings, which is just one thing.

Trapezoid Rubber Magnetic Chamfer

If the joints are not properly treated or cut corners, although there may be no problems within one or two years after the completion of the project, there will be water seepage after three years, and the cost of future maintenance is quite high.

If a technology or process does not improve productivity, has no cost advantage, or even significantly increases costs, and its quality cannot be guaranteed, then it has no promotion value.

For any technology, both feasibility study and unfeasibility study should be done.

G: There are still many differences between the laboratory and the site control.

E: Many frames in Japan are cast, and the connection method is basically similar to ours (or we use it for modification), so it is not a technology, but a management problem.

B: I agree with xxx very much that assembly should not be a new topic, nor should there be too strong policy support and strong promotion measures.

So why are foreign precast buildings so successful? Because the foreign assembly technology is relatively mature and the parts are standardized.

▲ Click the blue words above to follow the PKPM official official account! Article source: According to unreliable information, xx Municipal Construction Committee requires that when all projects of xx are submitted for drawing review, precast buildings shall not use vertical load-bearing components (i.e.

Mao Hongbin always said in his WeChat: precast building may be a good thing, but not all good things are feasible.

Fifthly, due to the nonstandard components, PC factories need many kinds of “molds”, PCs need maintenance period, PC finished products need to be stacked on site, how much space does a PC factory need to meet production and needs? Now, the precast buildings are being built in developed cities, and the land in developed cities is very expensive, so the cost of building a PC factory is very high.
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In addition, the number of PC installers on the site is new, which was not originally available.

Each splice is actually a weak point.

I don’t know how the seismic performance is? Do you have any friends who have done this research.

The self-consciousness and self-discipline of construction personnel cannot be tested in China’s construction projects.

In fact, the total labor consumption of precast buildings will not decrease, and may still increase.

Its quality depends too much on the on-site operation.