The temperature force causes the cracking of the outer wall, resulting in water leakage.

The second is the inner wall panel.

Our large venues are basically dominated by steel structure.

The third is the problem of exterior wall panel, which is the most complex problem and the biggest obstacle to the development of our steel structure in the field of civil construction.

I combed it and found that there are 12 indicators for the exterior wall panel: ① meet the stress; ② Anti cracking; ③ Water leakage prevention; ④ Insulation; ⑤ Fire prevention; ⑥ Sound insulation; ⑦ Cold proof bridge; ⑧ Door and window composite; ⑨ External finish composite; ⑩ Easy to manufacture; ⑪ Facilitate construction; ⑫ Cost control.

The interlayer displacement of any concrete shear wall structure is easy to reach one thousandth, but if the steel structure reaches one fifth, the steel consumption will be greatly increased.

▲ PK Ⅲ plate saves steel consumption, adopts 1570 grade stress relief steel wire, and its tensile strength is 4.2 times that of grade III steel, which is less than that of other laminated plates and has good crack resistance.

In recent years, both the Ministry of housing and urban rural development and the State Council have proposed to vigorously promote precast buildings, which of course includes steel structure.

At the same time, PK Ⅲ plate long line production platform has high standardization degree and high manufacturing efficiency.

The production efficiency is higher than that of concrete truss laminated plate, and the investment of equipment is also relatively low.

The internal wall panel adopts light internal wall large panel to solve the problem of wall panel cracking..

The steel itself is easy to deform.

At present, the development of steel structure is actually promoted by the development of PC industry.

We personally believe that PC actually promotes steel structure.

There are many small beam and small column nodes, and the cost is irregular.

The maximum area of a single board can reach 20 square meters, the weight is only 1.7 tons, the single board area is large, the board is thin, the weight is light, there is no empty board, and the support is less, which makes the construction efficiency high.

The thermal insulation of the outer wall is essential, and the thermal insulation often conflicts with fire prevention.

The steel structure in the field of public buildings has developed very well.

The efficiency is not matched.

I have been thinking about a question.

At present, the state vigorously promotes precast buildings, which includes steel structure.

We can’t afford thousands of yuan per square meter.

For example, if the outer wall panel needs to resist gravity, it is also necessary to calculate the wind load and material internal force.

Compared with the shear wall structure, it can not form a price advantage.

Why do people like brick houses and concrete houses? Because the wallboard can store heat, it can adjust the heat balance of the room.

5m2.

The first is the floor problem.

It contains the painstaking efforts of academician Zhou Xuhong, Professor Wu Fangbo and other technical leaders.

The most important thing is the temperature force.

The upper pole of the truss on the PK Ⅲ plate is made of steel pipe filled with mortar to form a large compression area.

Source: Shandong wansida Construction Technology Co., Ltd.

It is easy to catch fire when pasted with thermal insulation.

The composite of doors, windows and external finishes should also be convenient for manufacturing and construction.

As long as it deforms, the inner wall of the brick The internal walls of the bridge slab will crack, which is a pain point for our steel structure to enter civil use.

Among them, the three plate problem is prominent, that is, the floor slab, inner wall plate and outer wall plate.

1m, with a length of 2.1 ~ 9.0m, which acts together with the cast-in-place layer to form a laminated plate.

Although our floor is very thin, it has strong stiffness.

The advantage of steel structure is long-span space structure.

Usually, it is controlled to more than one third of the concrete shear wall structure, which is one third of the concrete shear wall structure.

Magnet Recess Former

The thickness of the baseplate is 35mm40mm and the standard width is 0.5m1 0m1.

Our steel structure construction is particularly fast, while the cast-in-situ slab construction is particularly slow, which leads to the problem of mismatch of construction efficiency.

When all these are met, this is a good wall.

For the third board problem, we have developed many new products to solve it.

It is like pulling the same car with cattle and horses.

We also need to consider the cost performance.

Therefore, to be a successful exterior wall, these twelve indicators are indispensable.

The steel structure is relatively flexible, which leads to the crack problem of various strips and blocks.

Many of these twelve indicators are interrelated.

The problem of the “three plates” is how to enter the field of civil housing.

Finally, the cattle are dragged to death and the horses are tired to death.

Why did PC develop by leaps and bounds in two or three years, while we have promoted steel structure for 20 years, but we feel very hard and tired.

Our latest PK Ⅲ slab is composed of C40 and C50 concrete baseplates, 1570 grade stress relief steel wire and concrete-filled steel tubular truss.

At present, the state is also strictly requiring building energy conservation.

▲ structural diagram of PK III type plate ▲ the construction of pkiii type laminated plate in office building has no support system, and the construction process of ordinary reinforced truss laminated plate is full of scaffolds.

Most of our civil houses are small bays with a width of three or four meters, which makes our components very small.

Firstly, PK prestressed concrete composite slab is used to solve the above floor problems.

Now there are more and more bridges with steel structure.

Of course, there are also factors causing the cracking of the plate itself.

At present, we have achieved a maximum length of 12M, which can effectively reduce the application of secondary beams and greatly improve the construction efficiency.

This technology has been used for 15 years.

Author: Zhang Bo, Zhang Shuhui, we have done a lot of steel structure and PC projects.

In the past, many steel structure buildings used more cast-in-situ slabs, and I also did so, because profiled steel plates were expensive, not willing to use, and the cost was high.

Now, steel structure and PC can be said to be a combination of soldiers, and will work together to promote the development of precast buildings in China.

Once the water leakage enters, it is difficult to discharge, and there will be freezing and thawing problems in the north.

The second is the problem of interior wall panel.

Compared with the common concrete truss laminated plate, only one end of the beard reinforcement is left, which does not interfere with the end beam, and the installation is convenient and very convenient.

Solution to the “third board” problem.

It operates efficiently from reinforcement blanking, concrete distribution, slab lifting, transportation and cleaning.

They can’t run fast.

The temperature difference of the outer wall, especially the smooth surface, can reach 50 degrees every day.