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When you consider the building materials used in a new construction project, you will feel uneasy. In fact, by choosing steel (rather than wood, stone, brick, etc.), you have already taken the first step to ensure that the completed project produces the best results. Steel is attractive because of its unparalleled strength-to-weight ratio, ductility, price, aesthetics, and consistency of composition from the beginning. There are more and more applications of agricultural steel building in agricultural production. Let’s take a look below.
What is the significance of the development of agricultural steel building?
How to set the power supply in agricultural steel building?
What are the components of the agricultural steel building organization?
What is the significance of the development of agricultural steel building?
The economic benefits of the development of agricultural steel building are good. First of all, the entire building does not require beams and bars, and the cost is only two-thirds of the light steel structure, and the larger the span, the lower the cost. In addition, the construction of agricultural steel building can greatly shorten the construction period, and the daily construction area can reach 1000m, which greatly saves the construction of machinery and labor costs.
The social effect of the development of agricultural steel building is significant. The construction period of modern large-scale projects is closely linked to economic benefits. Because we have adopted agricultural steel building development, the construction of the project is completed ahead of schedule, which creates good conditions for agricultural production units to put into use in advance, and the social effect is significant.
How to set the power supply in agricultural steel building?
1. The main distribution box in the agricultural steel building should be installed near the power source, and the distribution box should be installed near the electrical equipment or power-using area.
2. The distribution box in the agricultural steel building is made of iron plate.
3. The distribution box in the agricultural steel building should be equipped with a working neutral terminal board and a protective neutral terminal board.
4. The metal box, metal base and shell must be protected and connected to zero. The distribution box must be protected from rain and moisture. There must be a secondary leakage protector in the distribution box, and each electrical equipment should have its own dedicated switch box, which must implement "one machine, one switch, one leakage, one box", equipment and lighting are disconnected, all power distribution The boxes are all equipped with doors and locks, and a dedicated person is responsible for keeping them, and a regular inspection and maintenance system is implemented.
What are the components of the agricultural steel building organization?
(1) Structure made of cold-formed thin-walled steel;
(2) Structure made of hot-rolled light section steel;
(3) Structure composed of welded and high-frequency welded lightweight steel;
(4) Structure made of round tube, square tube, rectangular tube, etc.;
(5) Structure made of components welded from thin steel plates;
(6) The structure made by the combination of the above various components.
Qingdao Xinguangzheng Steel Structure Co., Ltd.. has been committed to providing customers with agricultural steel buildings and perfect after-sales service so that customers can invest easily, use them with confidence, and have no worries.
Introduction of Pakistan Prefabricated Steel Structure Construction Chemical Factory
Project Area: 4225 ㎡
Project Finished Time: Built in 2019-2020
Project Location: Lahore
Project Detail: Multi-story steel structures
Project Total Steel weight: 600 tons.
Company information of Pakistan Prefabricated Steel Structure Construction Chemical Factory
A brief introduction to you about our company first, then you can contact me if there is suitable project in the future.
1200 workers, 360000 ㎡ non-dust workshop, 25 years experience, CE, ISO9001, ISO9712, ISO3834, BV, SGS certificated, one hour reach Qingdao port, our company, as a manufacture, this is how we keep good quality and competitive prices for global valued customers.
We provide steel building design, farm house design, manufacture and installation service.
Project Introduction:
Solomon office project is a two-story frame structure, with a building area of more than 1500 square meters. The first floor is maintained as aluminum-plastic plate curtain wall and part of glass curtain wall, the second floor is maintained as glass curtain wall, the roof is glass wool composite plate, and the parapet part is aluminum-plastic plate.
Personnel involved in design and construction refinement: Liu Kangning, Jing Yanyan
Total project amount: 2.94 million
Detailed address: Honiara, Solomon Islands
The following project related parameters:
Area: 1500 square meters
Eave height: 7M
Ridge height: 8M
Number of floors: two
Wind speed: 176km / h
Load: second floor load: 450kg / m2, roof: 30kg / m2
Shapes: Framing
Steel consumption: 90 tons
Purpose: Salomon Telekom office and warehouse
Detail of Prefabricated Steel Structure Building Office in Solomon
Main Characters of prefab steel warehouse
· Super Aseismatic
Most part of the structure will be consisted of cold formed steel members, this system aseismatic grade can reachto 8.
· Wind Resistance
Steel structure building has the performance of high strength, solid rigidity and good deformation capacity, can resist strong wind for 50m/s.
·Durable
The steel material will be painted or galvanized as customers' requirement to be more anticorrosion and rustproof, the lifespan of the structure can be reach to 50~70 years.
·Heat Insulation
Sandwich panel can improve the insulation performance of the building, effectively avoid the phenomenon of "cold bridge" wall
·Environment Protection
Little waste for pollution in construction, 100% steel structure materials can be recycled, most of other related materials also can be recycled.
·Easy and Fast Build
Dry construction, will not influenced by the weather and environment, save much time and labor cost. One 300m2 steel structure building, can be finished in 30 days by only 5 workers.
Prefab House refers to a building where parts and components produced in a factory are assembled and connected at the construction site. Steel structure prefabricated buildings refer to steel structure components produced in factories and assembled and connected at the construction site.
Different countries have different understandings and practices of the housing system, but Prefab House generally refers to the main project of the house. Different residential products are formed due to the selection of different structural materials, structural types and construction methods, and constitute a number of corresponding residential products ranging from design to The complete technology of construction. The steel structure residential building system uses the steel structure form as the basis for the classification of the building system and becomes a branch of the building system.
The material of Prefab House has good homogeneity and isotropy, which is an ideal elastic body, which is most in line with the basic assumptions of general engineering mechanics; the material has good plasticity and toughness, can have large deformations, and can well withstand dynamic loads; construction period is short ; It has a high degree of industrialization and can be used for specialized production with a high degree of mechanization; it has high processing accuracy, high efficiency, and good airtightness, so it can be used to build gas tanks, oil tanks, and transformers.
In the future, the steel structure of Prefab House should study high-strength steel to greatly increase its yield point strength; in addition, new types of steel should be rolled, such as H-shaped steel (also known as wide flange steel), T-shaped steel and profiled steel plates, etc. The needs of large-span structures and super high-rise buildings.
(1) Light weight and high strength. Due to the use of steel as the load-bearing structure and new building materials as the enclosure structure, Prefab House generally uses steel structure to build residences that weigh about one-half of the weight of reinforced concrete residences, which reduces the weight of the house and reduces the cost of basic engineering. Since the building area occupied by the vertical force-bearing member is relatively small, the use area of the house can be increased. At the same time, because the steel structure residence adopts a large bay and large depth column network, it provides residents with a large space that can be flexibly separated, which can meet the different needs of users.
(2) The degree of industrialization is high and meets the requirements of industrialization. Most of the structural components of Prefab House are made in factories, which are easy to install and suitable for mass production. This has changed the traditional way of housing construction and realized the transformation from "building houses" to "manufacturing houses". Promoted the transformation of the housing industry from extensive to intensive, and at the same time promoted the development of productivity.
Qingdao Xinguangzheng Steel Structure Co., Ltd. has worked on the production of Prefab Houses for several years. You can find the best Prefab House in this company.
Nowadays, more and more industrial parks prefer to build workshop, warehouse, office and other buildings by steel structures. Why are steel structures so popular with the public? It is mainly due to the four excellent functions of steel structure "light, fast, good properties and economical".
1. Light
The steel structure has the characteristics of light weight and excellent stress function.
Steel has the smallest ratio of density to strength compared with concrete and wood. For example, the weight of steel roof trusses is only 30% or even 25% of the same concrete roof truss under the same load and strength conditions. The weight of the steel structure house is about 50% of the reinforced concrete house, but the usable area is about 4% higher than that of the reinforced concrete house.
2. Fast
The steel structure is prefabricated in the factory then bolts contacted installation on site. It has the characteristics of mass production of large pieces and high-level precision of finished products, which effectively shorten the construction period and reducing the cost to give high investment returen. Compared with the construction period of reinforced concrete structure engineering, the steel structure is only 1/3 to 1/2 of the reinforced concrete structure under the same conditions .
3. Good properties
The steel structure has good properties and high reliability.
Steel has uniform of texture, isotropy, large elastic modulus, good plasticity ,good resistance and is an ideal elastic plastic body. Therefore, the steel structure will not suddenly break due to occasional overloading or partial overloading, it can adapt to the oscillating load, and the calculation model can reflect the mechanical properties of the steel well, so the analysis is accurate and reliable.
4.Economical.
The cost of steel structure is higher than concrete structure from the raw materials only, but the construction speed of steel structure is about 50% faster than concrete structure, which will save a lot of time and cost. The steel structure is more than 50% lighter than the overall weight of the concrete structure house, so that the cost of basic treatment and transportation will be reduced. Building is a systematic project includes many items, such as planning, manufacturing, transportation, installation, maintenance and management. Therefore, from the overall point of view, the steel structure is more cost saving.
Project Area: 23408 sqm
Project Usage:Pakistan Cola workshop
Project Location: Lahore, Pakistan
Project weight of steel structures: 760 tons.
Project Detail:
Wall & Roof:0.5mm galvanized steel sheet +50mm glass wool+0.4mm galvanized steel sheet.
Span: Multi-Span 100m and 50m
Total Height: 12m
Project picture of Pakistan Prefabricated Steel Structure Construction Cola Workshop :
Company information
A brief introduction to you about our company first, then you can contact me if there is suitable project in the future.
1200 workers, 360000 ㎡ non-dust workshop, 25 years experience, CE, ISO9001, ISO9712, ISO3834, BV, SGS certificated, one hour reach Qingdao port, our company, as a manufacture, this is how we keep good quality and competitive prices for global valued customers.
We provide steel building design, farm house design, manufacture and installation service.
Prefab House only prefabricates some parts, and it must be poured in the same way as traditional buildings on the construction site. It is not "building blocks" as imagined. Therefore, no difference can be seen from the appearance of the house after it is built. Here we are going to introduce the Prefab House.
What are the reasons why people choose Prefab House?
What are the advantages of steel structure prefabricated houses?
What are the advantages of Prefab House for building plant?
1. Prefab House is of great benefit to energy conservation and environmental protection. Through factory production and on-site assembly construction, it can greatly reduce construction waste and construction sewage, reduce construction noise, reduce harmful gas and dust emissions, and reduce on-site construction and management personnel. Generally, it can save 20% of materials and about 60% of water.
2. The housing industrialization of Prefab House is not only beneficial to the capital flow of development enterprises, but can also increase the speed of housing listing, so it can greatly alleviate the current situation of insufficient market supply and adjust the supply relationship. After large-scale promotion, construction costs can be reduced, and it will also play a role in restraining housing prices.
3. Comprehensive cost accounting shows that the construction cost of Prefab House is higher than that of traditional construction methods, but after large-scale promotion, construction costs can be reduced.
First, the components of prefabricated houses can be industrialized in factories. The components are equivalent to standard products and can be installed directly after being transported to the site. It can be said to be convenient and fast. The construction field during the construction period, especially the unparalleled advantages.
prefabricated houses with steel structure are more stable than those made of welded frame steel. In addition, it is cheaper and more economical. Long service life, 50-70 years. Locked with bolts, it can be used repeatedly without any maintenance.
1. Large span: such Prefab House can realize single span or multi span, and the maximum span without center column is 36m.
2. Low cost: according to the requirements of customers, the unit price of Prefab House ranges from $150 / m2 to $300 / m2.
3. Convenient installation and short construction time: save manpower and cost for customers.
4. Prefab House has a long service life: up to 50 years
5. Environmental protection: such buildings are free of harmful substances.
6. Structural stability: earthquake resistance, wind resistance and snow resistance.
7. Others such as waterproof, heat insulation and energy saving.
The Prefab House produced by Qingdao Xinguangzheng Steel Structure Co., Ltd. has been exported to several countries. And there are several offices in the country, which is convenient for domestic customers to maintain. Based on technological innovation, their company constantly improves product quality and provides you with professional Prefab House.
Ⅰ. Steel column installation for steel structure construction
1. Installation sequence of steel column:
① Foundation setting out → ② binding → ③ hoisting → ④ correction → ⑤ final fixation
2. Installation method of steel column:
(1) Setting out:
A. Elevation control:
In this structural steel construction project, iron parts and "middle bars" are controlled according to the depth of concrete cup mouth, the elevation of steel column bottom and the embedded elevation in the center of the bottom of the cup mouth during the construction of concrete foundation (φ30 steel bars), the elevation of top surface of "middle reinforcement" is based on the elevation of steel column bottom, and the elevation error of iron parts is controlled in ± Within 1mm.
To ensure the steel column is embedded in the foundation accurately and firmly φ On the 30 "middle reinforcement", weld a steel plate with thickness of 20 at the bottom of H-shaped steel column, as shown in the figure below.
When installing structural steel column, clean the foundation cup mouth first, and check the embedded elevation control "middle reinforcement" in the foundation(φ The actual height of 30 steel bars) is not necessary because the elevation embedded in the foundation construction has been controlled precisely, and no additional iron pad is needed. The method is simple, fast and efficient for the treatment of steel column feet. The construction is fast and the force is reasonable. When the column is lifted, it can be adjusted freely in several directions when the elevation is unchanged.
B. Before installation, the vertical and horizontal axis reference lines of the foundation plane shall be placed on the top of the cup mouth by woodworking ink bucket as the installation and positioning line of steel column.
(2) Column binding and hoisting:
A. after the steel column enters the site, the steel column shall be arranged according to the position of the lifting plan, and the model and number shall be checked to see if they are correct. The plane position of steel column after entering the site is shown in the following figure.
B. Before the column is lifted, a horizontal line shall be drawn with red oil paint 2300mm upward from the bottom of the column, so as to recheck the plane elevation datum before and after the installation and fixation.
C. the column installation belongs to vertical hoisting. In order to keep the suspended column drooping and facilitate the positioning, the binding point is determined at the lower part of the bracket. In order to prevent the sharp edges and corners of the column edge from damaging the lifting rope during hoisting, the rubber belt of the old car is used to separate and cover the edge and corner lifting rope. Pay attention to binding firmly and easy to remove.
D. temporary steel ladder and high-strength bolt installation fixture of working platform shall be bound on the steel column.
E. in order to avoid the free swing of the suspended column, hemp rope should be used to tie the upper part of the column bottom as a restraint rope and adjust the direction.
F. according to the site conditions, the rotation method is adopted for hoisting
After the preparations before hoisting are ready, the trial hoisting shall be carried out first. When the height of the steel column is 200 mm above the ground, the hoisting shall be stopped to check whether the rigging is firm and whether the crane is stable. After confirming that there is no problem, the crane can be directed to slowly lift, rotate to the top of the cup mouth, and then slowly descend. When the distance between the bottom of the column and the design position is 40-100 mm, adjust the two datum lines of the column body and the foundation to reach the accurate position, direct the crane to descend to the position, and temporarily fix the column with steel wedge (or wood wedge) and wind rope to remove the hook.
• Key points of rotation method:
The method of lifting the column by rotating the column around the column base is called rotation method, as shown in figure a below. When the column is hoisted by rotation method, in order to improve the hoisting efficiency, when the steel column enters the site, the binding point of the column, the center of the column base and the center of the cup foundation should be placed on the arc with the crane stop point as the center and the distance from the stop point to the binding point (i.e. the turning radius of the column), as shown in Figure B below.
The steel column hoisting is shown in the figure below:
(3) Preliminary correction of column:
The column should be corrected on the side with large deviation first, and then on the side with small deviation.
A. The correction of column generally includes plane position, elevation and perpendicularity.
B. When the steel column is hoisted in place, it is one-time alignment, and generally it does not need plane re correction. For the elevation of the column, it has been used before hoisting φ The embedded "middle reinforcement" can accurately control the elevation. Generally, it only needs to be checked, and it does not need to be corrected. Therefore, the steel column correction is mainly to correct the verticality and recheck the elevation.
C. In this project, the perpendicularity of the column is observed, and two theodolites are used for measurement and correction.
• First, place the theodolite on one side of the column, align the longitudinal center wire with the baseline of the column base, and then fix the screws of the horizontal plate.
• Measure the center line of the column and observe from bottom to top. If the vertical center line is aligned, that is, the column is vertical. If it is not aligned, the column shall be adjusted until it is aligned with the longitudinal center line of theodolite.
• Measure the horizontal line in the same way so that the center line of the other side of the column is perpendicular to the horizontal axis of the baseline. After the column is accurately positioned, the column can be fixed.
• Verticality correction of steel column: distance adjusting screw rod and steel wedge are used. Due to the small contact surface of the long side of the column, the base plate is set during the construction. The details are as follows.
The manufacturing dimension of steel wedge is shown in the figure below:
(4) Final alignment and fixation of steel columns:
After the steel column is hoisted in place, the column correction mainly involves the adjustment of elevation and the correction of verticality; The correction method can use tools such as wind rope, Jack, crowbar and steel wedge (or wooden wedge) to apply vertical force and lateral force of pulling, jacking, supporting and prying to the steel column.
Adjust the verticality, positioning axis and elevation of the column. After confirming the correctness, the gap between the steel column and the foundation cup mouth shall be poured with C40 fine stone concrete. The expansive high strength grouting material is preferred.
Ⅱ Protection of site components:
1) The unloading of components shall be careful to prevent damage and prevent collision and extrusion between members.
2) The members shall be stacked in order at the designated site, and the number of layers stacked by steel beams shall not exceed 3 layers to prevent the members from squeezing and deformation.
3) Before hoisting, oil, sediment and dust on the surface of the components shall be cleaned.
Ⅲ The placement of components and the requirements for the site
1) When unloading, the components are unloaded directly near the installation position and within the radius of rotation of the crane. Mark the number clearly with a clear color pen to facilitate lifting.
2) The components are placed in order in the site, and a certain gap is reserved between adjacent components to facilitate binding.
3) The site shall be solid and flat, and the components shall not be polluted due to rain and snow, and the vehicle with 30 ton level can be walked.
Ⅳ Steel structure building installation
Preparation before hoisting of steel column:
Before hoisting the steel column, the cable wind rope shall be tied to the column body. The lifting point shall be at the bracket position, and the double wire rope shall be set up and down, and the snap ring can be checked to be qualified before entering the next work. Before hoisting the steel column, the positioning axis, foundation axis and elevation, cup opening size and the height of the bottom standard of the steel column must be inspected and handed over and accepted. The number, outline dimension, screw hole position and diameter of the steel column shall be comprehensively reviewed. After confirming that it meets the requirements of design drawings, draw out the installation center line and the lower end elevation line of the steel column.
Ⅴ Steel column hoisting
(1) installation method of steel column
Before lifting the steel column, the wooden board shall be fixed at the column foot to prevent damage to the column foot and other structures.
Special hoisting steel wire rope is used for steel column binding. Wood or rubber sheet shall be used to prevent damage to the steel column.
The steel column is installed by a 25t truck crane. When the steel column is lifted, the crane shall hook and rotate the arm while lifting the steel column to make the steel column vertical away from the ground.
(2) positioning adjustment and temporary fixation
When the steel column is lifted to 200mm above the base cup mouth, it will be stable, and it will fall slowly at the base cup mouth. Avoid hitting the concrete edge of the foundation cup mouth during falling. After implementation, use special angle ruler to check, adjust the steel column to make its positioning line coincide with the foundation positioning axis. Three people are required to operate the adjustment, one person moves the steel column, one person helps to stabilize and the other person conducts the test. The positioning error is controlled within 2mm.
(3) when adjusting the elevation of the steel column, place the pad iron at the bottom of the cup foundation, use the level to super level the bottom plate elevation of the steel column as the top elevation of the pad iron, so that the elevation after the steel column is in place can meet the design elevation requirements, mark the elevation datum point on the column body, and then use the level to measure the installation elevation after it is installed in place.
(4) the verticality of the steel column shall be preliminary adjusted by the level ruler. Then two theodolites are used to observe from both sides of the column at the same time, and the adjustment is carried out by relying on the cable wind rope. As shown in the figure below:
Diagram of verticality adjustment of steel column
(5) after the adjustment, use eight iron wedges to position the gap between the bottom of the steel column and the base of the cup mouth, and then spot weld the column to make it stable.
Ⅵ Steel beam installation
Steel beams must be stacked in order on site for this steel work in construction. Sleepers must be placed in the middle of each layer of steel beams. Two lifting points for steel beam hoisting are selected on both sides of the center of gravity of the steel beam. The two lifting points should be 800mm away from the support and the middle of the span, and the distance between the two lifting points should be increased according to the length of the steel beam.
To ensure safety and prevent the sharp edge of the steel beam from cutting the steel wire rope, the steel wire rope shall be protected, the angle of the sling shall not be less than 450, and the steel beam shall be directly tied and rolled with the steel wire rope or lifted with a special fixture.
Before hoisting the steel beam, install the safety rope on the steel beam. When hoisting, hang two sliding ropes at both ends of the steel beam. Two people pull two sliding ropes respectively. The hoisting speed of the steel beam must be slow. In order to ensure safety, personnel should not stand directly under the beam. The cloth bags specially used for placing high-strength bolts are put on both ends of the steel beam. When the steel beam is hoisted above the position, the steel beam is put in place. The falling speed of the steel beam is controlled at 3m / min. two installers are arranged at both ends of the steel column head to prepare for the installation of the steel beam. When the steel beam is close to the in place position, two installers should hold the upper flange of the steel beam with their hands respectively, drag the steel beam to the in place position, and prepare to install the high-strength bolts.
Ⅶ Installation of retaining structure and support corner brace
1) Installation of roof purlin: when the main structural steel forms a frame section, the roof purlin is hoisted to the main beam of the roof with a crane and installed manually. The purlin can also be manually pulled onto the roof with a white synthetic rope for installation. After the installation of purlin, the purlin support is installed in time.
2) Wall purlin installation: when the main structure forms a frame section, the construction personnel stand on the scaffold platform and pull the wall purlin to the installation position with white comprehensive rope.
3) Corner brace installation: after the main body is welded, the corner brace is connected.
Ⅷ Measurement and correction of steel column
Verticality correction of steel column
When the steel column is installed and corrected, two theodolites are set up on the control line with 90 degree translation of 1 meter each other, and the theodolite operators observe the small steel ruler on the top of the column, measure the deviation of the steel column and direct the correction.
A. Control the verticality of the steel column between the first hoisting joints.
B. Steel column calibration is divided into four steps:
initial calibration during initial tightening; Re-calibration before final tightening; Tracking and monitoring during welding process; Final result measurement after welding.
The perpendicularity can be roughly controlled with a long level before the initial tightening, and it can be accurately corrected after the frame is formed. After welding, retest shall be carried out, and the measurement results shall be compared with those at final tightening, so as to be the basis for the next construction.
C. Verticality measurement method of C steel column
Initial correction: the perpendicularity of the steel column is preliminary adjusted with a level ruler.
Accurate correction of steel column perpendicularity: one column grid is used as an installation section for the hoisting of the main frame until the hoisting of three continuous complete sections is completed
After the whole is formed, the measurement correction can be inserted. Two theodolites are used to observe from both sides of the column at the same time, and the wind rope is used for correction and adjustment.
Ⅸ Steel structure survey
2) Elevation control of steel column
Based on the elevation reference point of the plane layer where the steel column is located, the deviation value of the horizontal elevation of the steel column is measured with the level gauge and the correction is directed.
3) Steel beam measurement
After the steel column is hoisted and corrected, the +1.00m control point shall be measured to each steel column according to the site level as the basis for vertical transfer of elevation and the elevation of beam installation; Pop up the center line of the steel beam on the surface of the steel beam.
The control axis is measured to the column body to control the beam position offset; The accuracy of beam elevation is controlled according to the control point of column elevation. Set up theodolite on the floor platform, and then look at the cross angle to the axis of the corresponding beam. Aim at the center line of the upper surface of the beam to the other end with theodolite to see if the number coincides with the axis of the beam.
Calculation of survey and lofting data
In this project, the computer automatic query method is used to calculate the survey and lofting data. The specific steps are as follows:
1) The establishment of data model
Firstly, according to the design coordinates and the dimension relationship of each building in the design drawing, the building, building axis, control line to be lofted and so on are drawn in AutoCAD according to the proportion, and the data model is established.
2) Survey and lofting data query
After drawing the survey loft data model, the survey loft data such as the angle and distance between the known basis (axis control pile, lofted axis, etc.) and the control line to be lofted are queried by using the command of dist of AutoCAD.
3) Advantages of computer automatic query
The method of computer automatic query is used to obtain the required measurement and positioning data. It is not only convenient to calculate, but also has high precision. The distance precision can be set to 0.1mm, 0.01mm, and the angle precision to 0.0 ", 0.00" or higher according to the actual situation.
Ⅹ Construction of high strength bolt
1. Preparation before installation
1) Test and inspection of high strength bolt
Anti slip coefficient test
The project adopts class 10.9 large hexagon high-strength bolts. The anti slip coefficient test of high-strength bolts shall be conducted by taking the most representative thickness of the plate in the project for test, and three groups shall be made.
The size of the specimen plate is as follows:
Axial force test
Randomly select the bolts to be installed at the construction site, and 8 sets of bolt pairs are selected for re inspection in each batch.
2) Transportation and storage of high strength bolts
transport
The form, size and technical conditions of high-strength bolt connecting pair shall be manufactured and supplied by the manufacturer according to batch, with factory certificate and high-strength bolt connection pair, which shall conform to the provisions of national standards gb1228-1231-84 and gb3632-3633-83. High strength bolts with large hexagon for steel structure
The connecting pair consists of a bolt, a nut and two washers. The combination of use shall meet the national standards, and the high-strength bolt connection pair shall be supplied with storage and transportation in the same batch.
The high-strength bolt connecting pair shall be installed and placed lightly during loading, unloading, transportation and storage to prevent the packing box from being damaged or damaged.
Storage of high strength bolt warehouse
1. the high-strength bolt connection pair shall be cleaned according to the specification, batch number and supply date of the packing box, and shall be kept in the indoor warehouse, and the accumulation shall not be higher than 3 layers. The indoor moisture-proof, long-term dry, rust and dirt contamination shall be prevented, and torque coefficient shall be prevented from changing. The bottom layer shall be more than 300mm above the ground level.
2. when installing on site, the quantity of high-strength bolts required on the day shall be issued. The rest should be kept properly. Do not put it in disorder, damage the thread, and be contaminated with dirt.
3. before using the long-term storage high-strength bolt connection pair, a comprehensive quality inspection shall be conducted again. If any abnormal phenomenon is found after unpacking, the inspection standard shall be conducted according to the relevant provisions of national standards gb1228-1231-84 and gb3632-3633-83. It can be used after being qualified.
3) Construction management of high strength bolts
1. Construction Manager
When carrying out the construction of this high-strength bolt, the high-strength bolt manager shall be determined first to be responsible for the project management, quality management and guidance of the construction personnel.
2. weather management (climate conditions)
In principle, no operation shall be carried out during rainfall and snowfall. If rain or snow fall occurs during operation, the speed shall be accelerated to lock the unfinished ones
3. friction surface management
Before tightening, the friction surface shall be inspected first. If there are any attachments to reduce bearing capacity of friction surface, such as rust, oil, paint and residue, metal brush, sandpaper and oxygen acetylene flame shall be used for removal.
4) Construction of high strength bolts
1. final tightening of temporary bolts
Before inserting high-strength bolts, temporary bolts shall be used to tighten the connection tightly, if the materials of the connection parts are bent or warped, they shall be corrected.
If the difference of holes is within 2mm, it can be corrected by cutter.
If the difference of holes exceeds 2mm, reasonable treatment methods such as replacement of panel shall be adopted based on consultation with management personnel, and gas cutting and reaming are not allowed.
2. high strength bolt insertion
The nut and gasket of high-strength bolt shall pay attention to the installation direction, and install according to the following figure.
When inserting bolts, pay attention not to attach rust, dust, oil, etc. to the bolts. In addition, do not force into the bolt hole during construction to avoid damaging the thread.
3. initial tightening
After the temporary fixing bolts are locked, confirm the compactness of the components.
After initial tightening, mark with white marker through bolt nut, gasket and component.
When using the inspection wrench, although the torque value can be confirmed by the contact sound, it is easy to over tighten if the mechanism continues to apply force, so it should be noted.
4) Final tightening
After initial tightening, use special fastening wrench to lock until the neck is broken.
In principle, the bolts inserted on the same day shall be screwed out on the same day.