Main Factors of Steel Structure Damage and Its Reinforcing Technical Measures

 The main factors of steel structure damage are:

(1) Insufficient bearing capacity of the structure caused by load changes, extended service, and changes in codes and regulations;

(2) The component is deformed, twisted, disabled, dented, etc. due to various accidents, resulting in weakening of the section of the component, warping of the rod, cracking of the connection, etc.;

(3) Deformation, cracking and warping of components or connections caused by temperature difference;

(4) The cross-section of steel structural members is weakened due to corrosion caused by chemical corrosion and electrochemical corrosion;

(5) Others include mistakes in design, production, and construction, and illegal use and operation during the service period.

There are mainly three types of reinforcement technical measures for steel structures:

(1) Cross-section reinforcement method: Reinforce with steel in part or along the whole length of the member, and connect them into a whole to make them bear common force;

(2) Change the calculation diagram: add additional supports, adjust the load distribution, reduce the level of internal force, and force the displacement of the statically indeterminate structural supports to reduce the stress peak;

(3) Prestressed cable method: use high-strength cables to reinforce weak links of the structure or improve the overall bearing capacity, stiffness and stability of the structure.

The value of large-span space frame buildings

1. The structure should be light; the lightest space frame structure can withstand high-intensity pressure. This protects the environment in terms of energy saving, land saving, material saving, etc., thereby reducing pollution and providing people with healthy, efficient and adaptable space for use.

2. The construction period should be short; generally speaking, the construction time of the space frame is much shorter than that of the traditional concrete structure building, which is also greatly improved in terms of saving time, labor and resources.

3. The ductility should be strong; generally speaking, the rigidity of steel is very strong, but after it is processed into a building, the pressure it bears will also increase to a certain extent; and its performance in mobility, designability, and easy combination will come up. See, space framed buildings are also much taller than traditional concrete buildings.

The rigidity of the space frame is relatively high, so if it is organized with steel and high-strength steel wire for a combined purpose, the modeling of the space frame is a major feature of green buildings.

In the effective service life of the building, saving resources to the maximum extent has a great effect on people's green life. From the above three aspects, the texture, construction period and ductility of space frame buildings can play a role in Green energy-saving effect combined with modern buildings.

Whether the space frame can achieve the above three points has a great relationship with the designer's design concept and the materials used. The green design concept of steel structure was introduced into the world, but the initial stage was not very smooth, so there were many The novel space frame structure is complementary to the human landscape and green buildings. The concept of lightness, speed, goodness and economy is the green development direction of the space frame building. The quality of the space frame does not depend on how much steel or The size of the volume is expressed, but the main purpose of the space frame is expressed through a reasonable amount of steel and a reasonable design form, which is the purpose of green buildings.

Problems that should be paid attention to when producing color steel plates

     The color steel plate has the properties of high mechanical strength and easy forming of steel materials, as well as good decoration and corrosion resistance of coating materials. Steel color plate is an emerging material respected in the world today. Many steel color panels play an important role in rapidly developing industrial cities, but there are often many problems in the production process of steel color panels. Today, let's talk about what problems should be paid attention to when producing steel color panels.

There are wrinkles on the edge of the steel color plate. When there is no problem with the equipment, the original existence of the substrate generally occupies a large proportion. The wrinkles of the hot-dip galvanized steel plate are mainly caused by the existing technology of the galvanizing production line and the failure of the equipment. It is generally understood It is not difficult for friends of galvanizing process to solve this problem. Judging the quality from the appearance of the steel coil: Generally speaking, the appearance requires neat winding, and there are no burrs, serrated edges, and obvious gaps on both sides of the steel coil. diverse issues.

The lines of the steel color plate are not smooth, and the paint or back paint after the product comes out has the phenomenon of paint leakage, which is called in the industry: lines. This kind of problem is generally an unavoidable problem for every manufacturer. There is a part of impurities in the paint, part of the reason for the equipment, and a proportion of the factor of the substrate.

The color difference on the surface of the steel color plate is partly related to the quality of the paint. There are also practical problems in the production process. The type of substrate also occupies a certain proportion. The steel color plate produced by the process and raw materials will appear different.

There are holes and missing coating on the surface of the steel color plate, because the quality of the substrate is defective. If the substrate has serious edge damage and gaps, and there are holes in the substrate, the painting staff will open the painting equipment according to the industry standard operation requirements and let it skip. , it is inevitable that there will be leakage phenomenon.

There is a bulging phenomenon on the wave edge or the middle of the steel color plate: the main reason is the quality problem of the substrate. The predecessor of the substrate is rolling hard, and the wave edge phenomenon caused by uneven thickness is the most, and the other is less due to equipment problems. This is the actual reason. If the substrate is not waved and painted, the general situation is: It is caused by the abnormal operation of deviation correction or other equipment.

The paint peeling off the surface of the steel color plate: the production unit should check the pressure and whether the equipment operation system is normal and good, whether the bearing is working well, and whether the pressing action of each group of steel rollers of the tile press is consistent, there will be actual interference problems. . Due to the sharpness of the pressing wheel of the new press equipment, it is easy to cause scratches on the dry film of the paint on the steel color plate. It is recommended that customers pay attention to such problems. The quality of the paint is the most important thing that depends on the quality of the product. The weather resistance, flexibility and hardness of the paint film are proportional to the inspection results of the product, which means that the quality of the paint is qualified, such as: impact and wipe resistance. Both T-bend and T-bend can reflect the actual quality problems of the paint. If there is a substandard operation within the scope of the process flow, the cause must be immediately found and substantive adjustments should be made.

Design standard for metal roof system

 The application of the metal roof plate enclosure system has a long history abroad, and its product selection and technical standard system are relatively complete.

In 1996, Britain officially implemented the "Technical Specifications for the Application of Voltage Metal Plate Plates" (BS 5427-1). method. In addition, the industry manual or guidance documents formulated by research institutions or industry associations in some regions and countries have important guiding significance for the design and application of the metal enclosure structure. The more influential industry standards are the series of technical documents of the metal outer surrounding structure manufacturer association in the European region and the metal building system manual of the North American Metal Building Manufacturer Association.

Our country has also continuously compiled national product standards such as "Building Voltage Steel Plate", "Aluminum and Aluminum Alloy Polying Plates", and "Metal Platform Plate for thermal insulation". At the same time, the improvement of national technical standards, the "Technical Specifications of Slope Roof Engineering" and "Technical Specifications for the Application of Voltage Metal Board" specifications will be more conducive to the application and development of metal roof technology.

Arched corrugated steel roof gable wind resistance column

The gable wind-resistant columns can be designed according to the conventional design. Under normal circumstances, the metal arch corrugated roof project should be closed. In the open or semi-open situation, due to the uncertainty of the wind load of the roof and the substructure, the connection between the metal arched corrugated roof and the substructure is generally hinged or fixed. According to the simplified calculation model, the design of the substructure is much simpler compared to the conventional structure. The ring beam, column (wall) and foundation of the lower structure are designed according to the bearing reaction force calculated by the upper arch corrugated steel roof structure analysis, and the whole structure can be simplified as a series of statically indeterminate members for analysis, calculation and design.

The arched corrugated steel roof situation is more complex and difficult to predict. At this time, part of the gable above the ring beams at both ends of the roof should be closed, and wind-resistant columns should be set up if necessary. On the one hand, it can beautify the architectural effect of the roof, and more importantly, it increases the overall stiffness of the roof and increases its wind resistance.

Such as the waterproof and anti-corrosion treatment of the arch foot point of the arched corrugated steel roof structure, the setting of the lighting belt and the ventilation cap and the node treatment, thermal insulation, lightning protection and fire prevention, etc.

Large-span Complex Steel Structure Construction Characteristics

SAFS Steel Structure Engineering Co. LTD would like to introduce the construction characteristics of large-span complex steel structures here.

Firstly, it is of a high construction difficulty. For engineering projects that apply large-span complex steel structures, they usually have the characteristics of large space ratio, large project scale, huge workload of related projects, and large amount of engineering materials and components required and so on. This shows the difficulty and complexity in engineering construction. Due to different material components, there are many differences in structure, form, size, etc., so it will be more difficult to set out in specific construction.

Secondly, it requires high installation accuracy. Under normal circumstances, the large-scale large-span complex steel structure project is mostly a project undertaken by the government, which means that the project completion degree of the project will be reflected in the society as a kind of construction level, so the requirements for the construction of related projects are numerous and strict. For example, in the installation and processing of components, the accuracy of the relevant steps must be refined within the relevant regulations, and the joint construction must be carried out in strict accordance with the national welding seam indicators, so as to ensure that the welding seam effect and installation accuracy.

Large-span complex steel structure projects have strict requirements on construction materials in modern buildings, because they involve many aspects. In order to carry out the normal orderly construction work, the quality and strength of the steel are increasingly stringent in the steel selection process.

Large-span steel structures also require prestressing technical support. In the construction industry, prestressing technology is a vital technology to ensure the quality of design and construction work. In large space and complex steel structures, prestressing technology is mainly used in cable-membrane, cable dome, and overall expansion and contraction in innovative structural buildings.

Steel structure space frame building - the pillar of future construction technology

       A new type of building system of steel structure building has the industry boundaries between the real estate industry, construction industry and metallurgical industry, and is integrated into a new industrial system. This is the steel structure building system that is generally optimistic about the industry.

Compared with traditional concrete buildings, steel structure buildings replace reinforced concrete with steel plates or profiled steels, which have higher strength and better earthquake resistance. And because the components can be manufactured in factories and installed on site. Therefore, the construction period is greatly reduced. Due to the reusability of steel, construction waste can be greatly reduced, and it is more green and environmentally friendly. Therefore, it is widely used by countries all over the world and is used in industrial buildings and civil buildings.

Take the stadium space frame as an example. The stadium refers to a 400-meter runway (including a football field in the center) with fixed road teeth. Outdoor track and field venues with more than 6 runways and fixed stands. The site area is huge, and the roof is usually a transparent semi-closed structure. The stadium space frame structure has good integrity, high rigidity and good seismic performance, and can create a large-span column-free space, which is widely used in small and medium-sized stadium projects. In large-scale stadium projects, it is necessary to form a composite structural system with other types of structures to play their respective advantages. After careful and strict anti-corrosion and fire-proof treatment, the space frame parts are basically maintenance-free within the service life, and the cost performance is very high.

At present, the application of steel structure buildings in high-rise buildings is becoming more and more mature, and it has gradually become the mainstream construction technology, which is the development direction of future buildings.

Precautions for construction of steel structure fireproof paint

      1. The steel structure fire protection spraying protection should be constructed by a professional construction team that has passed the training and has the corresponding construction qualifications. Strict construction plans are formulated according to project characteristics and product selection. The physical and chemical properties of coatings can be sampled according to the needs of the project according to the specified proportion before the project is carried out. For intumescent fire retardant paint, different parts should be selected to test the foaming performance during construction.

2. The surface cleaning of the base material of fire retardant paint should be strictly inspected as a process. Remove dust, iron filings, rust, grease and other substances that hinder adhesion, and do a good job of anti-rust treatment of the substrate. The primer and surface coatings in the fireproof paint shall be matched accordingly, and the primer shall not corrode the steel.

3. The thickness of the coating should reach the design value, and the joint parts should be thickened. The requirements of spraying site, surface treatment of components, filling of joints, paint preparation, number of spraying times, quality control and acceptance, etc., shall all comply with the current national standard "Technical Specification for Application of Fireproof Paint for Steel Structures" (CECS24). The coating thickness should be checked during construction (measured with a thickness gauge). If the cracks in the coating are common and the width is large, it should be studied and analyzed whether the process is correct and whether the mixing ratio of the coating is reasonable.

4. The spraying of fireproof paint should master the consistency of the paint, the pressure of the air compressor and the distance between the spray port and the component during spraying. The main observation during construction is that there are many splashes indicating that the construction parameters are unreasonable and should be adjusted. The amount of diluent in the coating should not be too much, otherwise the normal construction viscosity of the coating will be reduced, and the coating cannot be attached to the surface of the steel structure.

5. In the process of coating construction, it must be done after the previous coating is basically dried and cured. The protection method of the coating, the number of construction times and the thickness of the protective layer should be determined according to the construction design requirements. The coating thickness of each pass should be moderate, and it should not be too thick or not rolled evenly, so as not to affect the coating quality. Strictly follow the painting process, and do not leave safety hazards to the building in order to rush the construction period.

6. After the project is completed, it is not only possible to measure the thickness of the coating, but also to detect the color of the coating and the leakage and cracks by visual method. Tap the coating with a 0.75-1kg hammer to test its strength. Use a 1m ruler to check the flatness of the coating.

The role of the glass dome

      In order to create a comfortable urban leisure space and give full play to the affinity of urban public space, with the official appearance of the glass dome, the urban renewal of the "facade" of the Bund has added landmark buildings.China's distinctive glass dome is undoubtedly the China Port Museum in Ningbo, Zhejiang, and the adjacent national underwater cultural heritage protection base Ningbo Base. The 3 modules of the three glass domes above the roof consist of an irregular elliptical spherical hyperboloid structure.

The main frame of the glass dome is an aluminum alloy frame, and the stress frame is a steel structure. The panel is made of ultra-white tempered laminated glass and external glass. The decorative frame consists of aluminium alloy tubes of different sizes. According to the structure, it can be divided into mesh dome, tension dome, suspension dome and load-bearing dome. According to the material, it can be divided into brick dome, metal dome, film dome, glass dome and wooden dome.The ramps allow visitors to "symbolically rise above the heads of their room representatives".A "lightweight sculpture" at the center reflects the horizon into the interior, while sun visors track the sun's path to block sun gain and glare. The overall image makes people even more admire the greatness of steel structure construction engineers.

The importance of fire fighting equipment in steel structure buildings

In recent years, with the development of urban construction and the increase of high-rise buildings, the development of steel structure buildings in my country is very rapid. During the construction of steel structure buildings, construction waste and construction noise are reduced to a minimum. In addition, steel structure buildings have high seismic performance, easy reconstruction and demolition, and high recycling and reuse rate of materials. It is a green industry with harmonious and sustainable development between man and nature. Please do not ignore the related issues such as fire protection and anti-corrosion.

Due to the many shortcomings of concrete structure buildings, with the advancement of modern technology and the improvement of environmental protection awareness, steel structure buildings have been greatly developed. Whether it is for industrial or civil use, many builders tend to use steel structures. All kinds of steel structure houses stand in the alleys of big cities, which also indicates that a new round of changes in construction has come. Many construction parties strive to make the steel structure to meet the predetermined functional requirements such as safety, applicability and durability under the specified conditions and period of use at the lowest cost. But please don't ignore the firefighting facilities of the steel structure building in the later use. The following points should be paid attention to: the property rights unit, user unit or property management unit of civil public buildings shall implement unified management of the building, and can conduct regular inspections on each steel structure building to facilitate timely discovery of problems and active rectification. In the case of residential buildings, due to their private nature, it is difficult for management units to conduct long-term home inspections. Once the fire protection layer of the steel structure is damaged or fails due to aging, it cannot be found in time, resulting in long-term hidden dangers.

Destruction of fire protection layer of steel structure platform by decoration. Some owners usually renovate the building before use, even if fire protection measures are taken during the construction, due to the lack of professional knowledge of the owners and the importance of it, they did not protect it during the renovation process. Once the protective layer of the steel structure is damaged or even peeled off, it is often not repaired. Once a fire occurs, it will affect the safety of the main structure of the building and cause loss of life and property.

For the fire protection facilities of other civil buildings, such as fire alarm systems and automatic sprinkler systems, the national fire protection regulations have relatively clear requirements. Residential buildings have long been regarded as large-scale and wide-ranging economic buildings with relatively low cost and investment standards. Except for the high-rise residential buildings with a height of more than 100 meters and the high-rise residential buildings belonging to the first-class high-rise buildings, which should be equipped with automatic sprinkler systems, other types of multi- and high-rise residential buildings only need fire hydrant systems. It can be seen that, such as civil buildings that also use steel structure systems, the fire safety factor of residential buildings is relatively low because the regulations do not require the installation of automatic sprinkler systems. I hope everyone will not ignore the importance of fire protection in steel structure buildings.