The construction and installation of the steel structure depends on the connection of steel structure beams and steel structure columns, as well as other components. The connection methods of steel structures can be divided into three types, one is welding, one is rivet connection, and the other is bolt connection, and bolt connection is divided into ordinary bolt connection and high-strength bolt connection.
1. For the selection of high-strength bolts, you must choose products from regular manufacturers. Hebei Handie Fastener Co., Ltd. - a professional manufacturer of fasteners / Handie Company has been engaged in the production and research and development of fasteners for more than 30 years.
2. High-strength bolts must be properly kept by special personnel, and they should not be randomly thrown away. During the installation of the entire steel structure, the bolts should not be damaged, and other pollution should not occur, so as to prevent the bolt torque coefficient from changing, and The storage environment should be moisture-proof and corrosion-proof.
3. When installing high-strength bolts, use a bald crowbar and punch to align the screw holes of the upper and lower or front and rear connecting plates, so that the bolts can enter freely. If the error of the screw hole of the connecting plate is relatively large, it should be checked and analyzed and dealt with. If the adjustment bolt holes are invalid or the positions of the remaining partial bolt holes are not correct, electric reamers or manual reamers can be used to drill holes.
When screwing high-strength bolts, there are two steps. The first step is the initial screwing. When the axis of the steel column or steel beam is accurate, the final screwing should be completed within the same day to prevent omissions.
Steel structure bolts play a role in linking up and down in machinery. Bolts are needed for fixing in many places. So what are the standards and acceptance of steel structure bolts?
1. Hit the high-strength bolts with a 0.3kg hand hammer for a general survey to check whether there is any leakage; the tightening of high-strength bolts with large hexagonal heads should be divided into initial tightening and final tightening; the tightening of torsional shear high-strength bolts is divided into initial tightening , and finally twist. For large joints, it should be divided into initial screwing, re-tightening and final screwing, and the re-tightening torque is equal to the initial screwing torque.
The initial tightening torque can be found from Table 07-4: the initial tightening, retightening and final tightening of high-strength bolts should be completed on the same day.
2. If any non-compliance is found, then expand the inspection by 10% on this node; if there are still unqualified parts, re-tighten the high-strength bolts of the entire node; the friction surface of the high-strength bolt connection must ensure the determined treatment The method should not be changed without authorization; and the friction surface should be kept dry. If the construction is in rainy days, rainproof measures must be taken; after the high-strength bolts are installed, special wrenches should be used to tighten them in time. After tightening until it is close to the connecting plate, use a special torque wrench to tighten; the torque wrench used for construction should be calibrated.
3. Check the tightening torque: check the torque of 10% of the number of bolts at each node, but not less than one. Take any bolt, draw a straight line on the end face of the screw rod and the nut, loosen the nut by 60°, and re-tighten it with a torque wrench to make the two lines overlap. The torque measured at this time should be in the range of 0.9 Tch~1.1 Tch. The check torque (Tch) is calculated according to the following formula: Tch=k×P×d(N?M), when the friction surface gap t is greater than 3mm, add a backing plate, the thickness of the backing plate is not less than 3mm, and the number does not exceed 3 layers; backing plate Materials and friction surfaces are treated in the same way as components.
The application of high-strength bolts The construction steel structure has the characteristics of high bearing capacity, light structure, high precision, convenient on-site installation, and short cycle time. The use of prefabricated steel structures can greatly shorten the construction period on site. This method has been widely used in many buildings in the world, especially in the construction of large industrial plants.
Specifications and acceptance requirements for steel structure bolts
2023 03/13