1) Test and inspection of anti-slip coefficient test of high-strength bolts 10.9 grade hexagonal high-strength bolts are used in this project, and the anti-slip coefficient test of high-strength bolts should be made of three groups of plates with the most representative thickness in the project. The dimensions of the specimen plate are as follows: the axial force test is randomly selected from the bolt batches to be installed in the construction site, and 8 bolt pairs are selected from each batch for re-inspection.
2) High-strength bolt connection pairs for transportation, storage and transportation of high-strength bolts shall be manufactured and supplied by the manufacturer in batches with factory certificates. The form, size and technical conditions of high-strength bolt connection pairs shall conform to the provisions of national standards GB1228-1231-84 and GB3632-3633-83. The hexagonal high-strength bolt connection pair for steel structure consists of a bolt, a nut and two washers. The high-strength bolt connection pair should be handled with care during loading, unloading, transportation and storage to prevent the damage of the packing box and bolts.
High strength bolts are stored in warehouse 1. The high-strength bolt connection pair shall be cleaned according to the specifications, batch numbers, serial numbers and delivery dates indicated on the packing box and stored in the indoor warehouse. The storage height shall not exceed 3 floors, and it shall be moisture-proof indoors and dry for a long time to prevent rust and dust pollution and prevent the torque coefficient from changing. Its bottom layer should be higher than or equal to ≥300mm above the ground. 2. During site installation, high-strength bolts shall be distributed according to the required quantity of the day. Take care of the rest. Do not misplace, damage threads or be contaminated by dust. 3. Long-term storage of high-strength bolt connection pair before use, must conduct a comprehensive quality inspection again, after unpacking found abnormal phenomenon should also be checked. The inspection standard conforms to the relevant provisions of national standards GB1228 ~1231-84 and GB3632~3633-83. It can be used only after it is qualified.
3) Construction management of high-strength bolts 1. When the construction manager carries out this kind of high-strength bolt construction, he should first determine the high-strength bolt manager and let him serve as project management, quality management and guide the construction personnel. 2. Weather management (climatic conditions) In principle, no operation is carried out when it rains or snows. If it rains or snows during the operation, it is necessary to speed up the locking speed of the parts that are not fully tightened. 3. Friction surface management: Before tightening operation, first check the friction surface. If there are rust, oil, paint, residue and other attachments that reduce the bearing capacity of the friction surface, remove them with metal brush, sandpaper and oxyacetylene flame.
4) Construction of high-strength bolt 1. Before inserting the high-strength bolts, the temporary bolts should be tightened with temporary bolts to make the connection tight. If the material of the connection part is bent or warped, it should be corrected. When the hole difference is within 2mm, it can be corrected by reamer. If the hole difference is greater than 2mm, reasonable treatment methods such as replacing the splicing plate should be adopted on the basis of consultation with management personnel, and gas cutting reaming is not allowed.
2. High-strength bolt insertion
Pay attention to the installation direction of nuts and washers of high-strength bolts, and install them according to the following figure. When inserting bolts, be careful not to attach rust, dust, oil, etc. To the bolt. In addition, don't force the bolt hole during construction, so as not to damage the thread.
3. Initial tightening
After locking the temporary fixing bolts, confirm the tightness of the components. After initial tightening, mark bolts, nuts, washers and components with a white marker.
When using the detection wrench, although the torque value can be confirmed by the contact sound, if the mechanism continues to exert force, it is easy to tighten, so pay attention.
4) After the final and initial screwing, lock it with a special fastening wrench until the neck is broken. In principle, bolts inserted on the same day should be unscrewed on the same day. In principle, the final torsion is from the center to the end of the joint. For information about construction enterprises, award-winning achievements, builders under construction, enterprise honors, industrial and commercial information, legal proceedings, etc., please visit Zhong Da Consulting, Construction Link or follow the official account of Zhong Da Consulting WeChat for inquiry.
For more information about project/service/procurement bidding, and to improve the winning rate, please click on the bottom of official website Customer Service for free consultation:/#/? source=bdzd