The top chord assembly and welding steps of the space frame

The top chord assembly and electric welding of steel structure space frame work steps:

1.Put in the longitudinal bars of the upper chord plan space frame to check whether the longitudinal parts and specifications of the top chord ball are appropriate.

2.Put in the transverse bars of the top chord plan space frame to check whether the longitudinal parts and specifications of the top chord ball are appropriate.

3. According to the proper adjustment of the diagonal web member of the three-dimensional small assembly module, the longitudinal and transverse bars of the top chord and the electric welding ball are properly in place. The way to adjust the oblique web members to not only laser cut too long bars, but also to open the angle of view of the transverse bars with inverted chains, so that the rods are properly in place. Ensure the proper size of the top chord grid.

4. Adjust the gaps, and weld the upper chord members after the gap foundation reaches the standard.

5. After the upper chord is fixed, weld the lower chord ball and the transverse bar to make the connection strong.

6. Check space frame specifications and push forward gradually.

The installation of web member and upper chord should be carried out in coordination with each other.

7.After the completion of the installation of the space frame pavement, the project acceptance shall be carried out according to the general specifications of the strips or blocks for the installation of the space frame.

8. The space frame to be hoisted must be hoisted (lifted) after the welding process is finished, the welding appearance quality and the welding ultrasonic flaw detector are reported to reach the standard.

The causes of paint loss during the processing of steel space frame structure

The space frame steel structure is sanded and painted according to the requirements of anti-corrosion. The amount of paint is largely related to the thickness of the dry film, as well as the construction method and coating system.

Paint loss caused by the surface roughness of the workpiece.

When painting the spray-treated surface, the film thickness at the peak of the steel plate should be less than the waves film thickness. In order to meet the anti-corrosion thickness requirements at the peak (to avoid pitting corrosion), the paint "hidden" in the pits of the waves is equivalent to being wasted, which is the "steel plate roughness consumption loss". The following table shows the paint loss caused by different spraying methods (expressed in dry film thickness):

Paint loss caused by uneven film thickness distribution

After the film thickness reaches or exceeds the specified film thickness during the acceptance of the paint film after construction, the technical service representative, the supervisor or the owner will sign as normal, but the part that does not meet the specified film thickness will be required to recoat, so it will inevitably cause "excessive thickness" loss. The specific factors leading to uneven distribution of paint film thickness mainly include: worker proficiency, construction environment, simple or complex construction work piece (flat work piece), and construction method (no air spraying, air spraying, brushing, rolling).

Processing and construction waste

Space frame steel structure processing and construction waste refers to the waste of paint that is lost to the surrounding environment or the ground without reaching the surface of the construction workpiece. If there is no air spraying, the loss of paint is about 10-20%, if there is air spraying, the loss of paint is more than 50%, and the loss of rolling is about 5%. When the brush is well controlled, it is relatively less. Bridge spraying in high wind environment can cause more than 100% waste.

Waste of paint remaining in the container. After the paint is applied, the average loss of the paint remaining on the inner wall of the paint bucket and the rubber tube is about 5%.

In summary, the paint loss coefficient during construction is mainly caused by the loss of surface roughness of the workpiece, the loss of uneven paint film thickness, the waste of construction, and the waste of residual paint in the container.

Is the Steel Structure Sound Proof?

 In the case of steel structure, the first elements must be considered, but there are a lot of, especially sound insulation and noise reduction, we should pay great attention to it, then the application of steel structure can really play the actual effect of sound insulation and noise reduction?

(1) After adding the glass fiber cotton, it can reasonably block the circulation of goods in the middle of the gas. Because the sound can be spread, when a sound is blocked by an object as it travels, it can play a relieving effect, so it can reduce the decibel level.

(2) After adding the glass fiber cotton, it can change the actual effect of the audio in the whole sound transmission process. If you change the frequency problem of the audio, you can reduce it. In addition, it can also change the direction of the audio, so it can be solved between each other 

(3) In view of the steel structure, two walls can be applied to the design proposal, and after that have two walls, can give a voice two solutions on top, so a lower than before, and for the steel structure, it can change the malleability, reasonably reduces the solid state fast propagation in the middle of the building, the decrease in speed means that the quality of the sound is just beginning to diminish.

The above content is my detailed introduction of the application of steel structure can really play the actual effect of sound insulation and noise reduction, I hope can help you.

Do steel structure and steel space frame have to do fire protection?

Whether steel structure and steel space frame are painted with fire-retardant coating should be determined according to the fire risk category. The "Code for Fire Protection Design of Buildings" explicitly stipulates that Category D and E are not necessary to be painted, but Category C and above must be. Steel as a building material has some unavoidable defects in fire protection. Its mechanical properties, such as yield point, tensile strength and elastic modulus will drop sharply due to the increase in temperature. Therefore, it is very necessary to make steel space frame and steel structures for fire protection. Steel structures and stainless steel space frame usually lose load-bearing capacity at a temperature of 450 to 650°C, and then they occur great deformation that would result in the bend of columns and beams. This excessive deformation will make the steel unusable. Generally, the fire protection limit of unprotected steel structure is about 15 minutes. The length of this time is also related to the speed at which the component absorbs heat. To make steel structure materials overcome the shortcomings of fire protection in practical applications, it is necessary to carry out fire protection treatment. The purpose is to increase the fire protection to the limit specified in the design code. There are various methods to prevent the deformation and collapse of the steel structure in the fire. The key is to adopt different methods according to different situations, such as using heat insulation and fireproof materials to prevent frame from direct burning, reducing the speed of heat transfer to delay the time of temperature rise and strength weakening. But no matter what method is adopted, the principle is the same.

How to reasonably reduce the engineering construction and processing cost of space frame structure

How to reduce the engineering construction and processing cost of space frame structure？ Let’s take a look.

First, we can pay attention to the size of the entire project. Although the space is fixed, we can reduce the size of the entire project by reducing the amount of coverage. Once the entire size is reduced, then the price of our project is definitely lowered accordingly, which we believe everyone can understand.

Second, if the size of the grid cannot be changed, then we can focus on its design. There are generally three different design schemes, and the material costs used are different, such as the triangular vertebral design. Compared with the quadrangular pyramid design, the material cost is much more.

Third, in addition to choosing a relatively simple design with less materials, we can also save in the materials of the entire product, such as thinning the inner wall of the stainless steel pipe to make the material of the entire steel pipe If it is reduced, a considerable amount of expenditure can be saved.

No matter what method of price reduction is, it’s all based on engineering safety.

Hoisting steps of steel space frame structure

     The connection point of the steel space frame structure is a key step to connect the components of the junction and transmit the load. The development of an effective connection point design plan is crucial to the safety factor of the steel space frame structure, the production and installation, the construction schedule and the project budget. Immediate hazard. The connection points of the space frame are divided into internal connection points and rubber bearing connection points. The design plan and structure should comply with the requirements of effective support, reliable force transmission, simple structure, and convenient manufacturing and installation. Frame connection points are divided into several categories, each of which is electric welded thick steel plate connection point, electric welded hollow ball connection point, anchor bolt ball connection point, immediate intersecting connection point and welded pipe connection point.

The lifting steps of the steel space frame:

     1. Side-by-side high and low-span roof hoisting: be sure to install the high-span first and then the low-span, which is beneficial to the flatness of the high- and low-span steel beams.

     2. Side-by-side installation of large span and small span: be sure to install the large span first, and then install the small span. To

     3. Installations with larger side-by-side rooms and fewer rooms: first hoist the larger room, and then hoist the smaller room. To

     4. Hoisting of prefabricated components under most engineering construction conditions, the longitudinal prefabricated components are hoisted first, and then the plan view prefabricated components are hoisted, that is, the comprehensive installation method is selected for lifting. The layout of the hoisting machine and the line of operation of the space frame: the installation of the space frame should integrate the structural characteristics of the project, site conditions, and the working half of the crane on the spot, and carry out the layout of the hoisting machinery and equipment and the line of operation beforehand. The overall planning of the crane makes full use of the high efficiency of the crane to ensure the orderly development of the lifting.