Application Forms of Steel Structure and Key Points of Quality Control

Application form of steel structure

1.Box concrete column

Box concrete column is in the middle of the box column to join clapboard play a supporting role, inside the box column perfusion of high strength concrete (C50) grade, forming the mechanism of the two kinds of materials to work together, mutual support, to the eradication of the loads, when its strength has not yet reached the limit, to produce relatively large deformation situation.

It has three advantages: first, the construction operation is simple and convenient; Second, it has good seismic performance; Third, strong carrying capacity.

2.Lateral force support concrete tube structure

The reinforced concrete core tube formed by the elevator and stairs serves as the lateral force support of the shear wall, which improves the stability of the structure and plays a positive role in optimizing the lateral stiffness and improving the seismic performance.

3.Cast-in-place reinforced concrete building

The lower edge of the steel frame beam is used as the supporting formwork, and the bamboo sheet is laid on the top. Then the steel bars are laid according to the design and the C30 concrete is poured. Save the formwork material and shorten the construction period.

4.Composite exterior wall panels

In a way, wallboard, especially exterior wallboard, is more important than the structural system, because the main function of the building is realized by the exterior wallboard. If the wall panel is manufactured and installed on site, the wet operation can be declared to be canceled.

5.High-rise residential steel structure system

Energy-efficient housing can not only reduce energy consumption, help protect the environment, but also can make the owner's living cost greatly reduced. According to the relevant survey, people's understanding of energy-saving housing is deepening, and more than 70% of the people said they are willing to buy energy-saving housing.

6.Main lifting garage with steel structure

The installation of a three-dimensional lifting garage in the basement, three-dimensional multi-story parking equipment can be said to be a new type of equipment, because it can save space well, less investment, the flexible layout can achieve automatic layout.

Essential points of quality control

1.Quality control of embedded bolts

a When embedding bolts in the construction foundation, we should first be familiar with the drawings, understand the intention of the drawings and make the installation template.

b Embedded bolts shall be positioned on the main reinforcement and formwork of the column with the installation formwork and steel bar to ensure that the embedded bolts shall not be displaced by the construction of civil pouring concrete.

c The spacing and height between the bolts can be controlled within the allowable error range.

Protect the bolt thread from damage during concrete placement.

d After the completion of the civil engineering, check the elevation and axis of the anchor bolts with theodolite and level, and make a good record, and hand it over to the next procedure for acceptance.

2.Quality control of component manufacturing

The construction of steel structure engineering usually goes through two stages: factory fabrication and site installation.

The general production process of steel structure is divided into: lofting → blanking → splitting → cutting → erection → submerged arc welding → drilling → assembly → correction molding → rivet parts blanking → production and assembly → welding and welding inspection → antirust treatment, coating, number → member acceptance.

In the production of steel structure, according to the production process of steel structure, we should grasp the key processes for quality control, such as the control of the processing of key parts, the main components of the process, measures, the use of processing equipment, technology and equipment.

3.Quality control of welding engineering

a Before welding the steel structure, the qualification certificate of the electrode should be checked and used according to the instructions. The welder must hold the post certificate.

b Weld surface shall not have cracks, welding nodule, I and II welds shall not have pores, slag inclusion, arc pit cracks, I and II welds shall not have undercut, incomplete welding and other defects, I and II welds shall carry out non-destructive testing according to the requirements, and welder's steel mark shall be checked at the specified welds and parts.

c The unqualified welds shall not be disposed of without authorization and shall be disposed of after the modification process is determined. The number of repairing welds in the same part shall not exceed 2 times.

4.Quality control of the component installation

a Before the installation of steel structures, the quality of members shall be checked. When permanent deformation and defects of members exceed the allowable value, they shall be dealt with.

b The installation of the steel column shall check whether the pad iron under the column bottom plate is solid and flat to prevent the instability of the anchor bolts under the column bottom plate.

c Whether the control column is vertical and has no displacement, in the installation project, before the structure has not formed a stable system, temporary support measures should be taken.

d When the steel structure is installed to form a space fixed unit and is accepted as qualified, the construction unit is required to densify the space of the column bottom plate and the top surface of the foundation by secondary pouring with expansion concrete in time.

5.Quality control of fastener connection

a Pay attention to the processing quality of high strength bolt friction surface and protection before installation to prevent pollution and corrosion. Before installation, the anti-slip coefficient test of the friction surface of the high strength bolt shall be carried out, the factory certificate and batch number of the high strength bolt shall be checked, and the axial force test shall be carried out regularly for the high strength bolts with different batch numbers.

b The installation of high strength bolts shall be free penetration, and shall not be knocked or reamed. Therefore, certain bead mold should be prepared to control its deformation during the production of steel structure, and practicable fixed measures should be taken to ensure its dimensional stability during the transportation of components.

c During the installation process of the steel structure, the laminated contact surface should be smooth, the contact surface must be greater than 75%, and the edge gap should not be greater than 0.8mm. The installation process of high-strength bolts, including operation sequence, installation method, fastening sequence, initial screw and final screw, should be strictly controlled and checked, and the torque wrench of screw bolts should be calibrated. The end of the screw should be checked one by one, they owe screws, super screws should be screwed or replaced.

6.Rust removal and coating engineering

a The construction personnel should adopt different rust removal methods according to the requirements of the drawings and the rust removal grade.

b The quality control of the brushing project should be done before the steel structure is brushed, and the surface of the brushing component should not have foreign bodies such as welding slag, oil, water and burrs, and the number and thickness of the brushing should meet the design requirements.

c The coating materials must have a certificate, fire retardant coating project must be approved by the fire department of the construction unit construction.