Construction process and quality inspection of high-strength bolt joints

Construction technology and quality inspection of high-strength bolt joints in Shanxi construction Zhang Hongwei, Li Tianyi, summary, snails, snails, snails, snails, snails, snails, snails, snails, snails, snails, snails, snails, snails, snails, snails, snails The key role of bolts in steel structure installation engineering. Il text

Construction technology and quality inspection of high-strength bolt joints in Shanxi construction Zhang Hongwei, Li Tianyi, summary, snails, snails, snails, snails, snails, snails, snails, snails, snails, snails, snails, snails, snails, snails, snails, snails The key role of bolts in steel structure installation engineering.

Il document identification code into high-strength bolts is widely used in modern steel structure installation projects because of its strong connection strength, easy to loosen and disassemble. Instead of riveting and welding, high-strength bolt friction joints are currently commonly used. The construction quality of high-strength bolt joints plays a key role in steel structure installation engineering. therefore. Strictly standardize the various procedures of high-strength bolts from ordering to final coating, to avoid delays in construction due to insufficient preparation errors, and to scrap the bolts and produce quality accidents. Taking the completion of the high-strength snail joint of the 24th steel plate beam of Zhengzhou Ouhai double line as an example, the female heart 241 under-bolt welded steel plate beam must be assembled on site because of its super wide railway limit. It needs 22,10.98 lengths. 2,450 sets of large hexagonal high-strength bolts. Each set of bolts includes a 10 high-strength large hex nut, two. 03545 high-strength mat, 1 high-strength bolt connection pair installation steel beam must be tested before the assembly of the anti-slip coefficient and the bolt torque coefficient test 5 ä½¥ can be assembled after the steel beam is assembled, the rain-proof inspection board should be set up when assembling The surface must be dry. Clean and free of dirt. glitch. You should not work in the rain.

Assemble the steel beams with a sufficient number of punches and common bolts. And adjust and check the overall geometric size, after the qualification can be installed high-strength bolts, high-strength bolt and nut washers must be used in accordance with the batch number provided by the manufacturer. Do not change its factory state. Install according to the specifications required by the design documents. The threading direction of the bolt is subject to the screwing and maintenance. Place a washer on each side of the bolt head and the nut side. The side of the washer with the inner chamfer should face the bolt head and the nut support surface, and the 1I is installed when the splicing piece is installed. It is forbidden to force the bolts in, otherwise the thread will be damaged. The hole in question can be trimmed with a reamer and a drill bit. When trimming, the bolts around the hole should be tightened tightly, and the holes should be reamed. The shed is easy to remember; 5 the friction surface clearance should be less than 1 or it should be treated. 6 When the screw is applied, the high-strength bolt connection pair should be received according to the actual required quantity of each shift. Remaining threads and dirt.

2 Before tightening the high-strength bolt connection pair, calculate the final tightening torque of each batch of high-strength bolts according to the following formula.

The average torque coefficient of the human high-strength bolt connection pair.

Strong bolts are provided with two tensions and pre-tensioning for construction. Such as 221 high-strength bolt design pre-tension, 200 continents, construction pre-tension corpse = 220 research high-strength bolts are divided into initial twisting and final screwing. The initial and double tightening torques are the same as the final tightening torque. 50. The initial tightening and final tightening of the high-strength bolt connection pair should be completed within the same working day. Tightening should be done on the nut.

3 tightening sequence of high-strength bolts. It should be done from the stiff part of the node to the unconstrained edge. For large nodes, the rods should be moved from the center of the node to the circumference. The initial torque wrench and the final screw of the 4 high-strength bolt connection pairs should be fixed torque wrenches. The torque wrench must be calibrated before use. The error is less than or equal to ±5. Before and after the operation, the torque of the construction wrench must be corrected. The calibration method is carried out by using the hanging column code, etc. 2. The calibration record is made. After the high-strength bolt after the double-compression is checked. Apply the paint line to mark the thread and check the nut. The relative position of the washer to the steel plate is used to mark the retracement and check whether the washer rotates with the nut at the end and final screwing.

6 When the final screwing, the construction torque must be continuous and stable. The bolt washers must not rotate with the nut. Replace the high-strength bolts if there is any rotation. After the final screwing is completed, mark the nut with a different color of paint.

3 Quality inspection 1 High-strength bolt connection construction quality inspection should be carried out by full-time quality inspector and supervision engineer. 2 Check torque wrench must be calibrated before use. Torque error should not be greater than ±3 of the used torque value. Check torque Calculated by Li Tianyi 196 , male, graduated from Shijiazhuang Railway Institute in 1992, engineering machinery, engineer, China Railway 10th Bureau Group Company, Shanxi Taiyuan, 3,24 Shanxi Construction 2002.60 pumping high-performance concrete application in a project Li Chengming, He Wei on high performance concrete High strength, high fluidity, high density and volume stability, etc., detailed analysis of the selection requirements of raw materials and the design points of the mix ratio.

Specific technical requirements were also proposed for the construction procedures such as mixing and transportation of high-performance concrete for vibrating maintenance inspection.

Taiyuan Daily News Building is located at No. 214 Xinjian Road, with a construction area of ​​36,000, 2. High 95, and 28 underground. Shear wall reinforced concrete structure for the frame. 060 high-performance concrete is used for all frame columns and shear walls from the basement to the ground. In order to achieve the high strength, high fluidity, high density and volume stability peculiar to high performance concrete. The construction unit commercial concrete mixing station construction unit and the supervision company have done a lot of investigation and research demonstration. Finally, the expected results were achieved in the construction practice. Valuable exploration and practice for the application of high performance concrete in our province. The following is a brief introduction to the management and management of the 060 high-performance concrete in this project. The raw materials used are 1 cement 邯郸 Taihangshan brand No. 525 ordinary Portland cement, 叱 8 = 57.0 stable condensation time qualified; 2 sand Shanxi 忻州豆罗砂, fineness modulus 2.7, mud content 1.5, good gradation; 3 stone ten too. 1 The size of the gravel in the northern suburbs is 5, 2, 1 plus 0.7. Class of mud, and the 1 servant 1 powder produced by the company is not limited to the product. Biliang area 6000, 2, 5 high-efficiency water reducing agent Taiyuan City Yuanhua factory, 33 resin type high-efficiency water reducer water reduction rate 22 retarding pumpable, self-compacting; 6 mixing water drinking water 2 concrete mix design according to multi-party Statistics and empirical data. The construction strength of high performance concrete should not be less than 1.15 times the design strength grade. The water-cement ratio should be controlled in the design formula of 24 ordinary concrete mix ratio, and the average value of the torque coefficient of the high-strength bolt connection pair of 060 pumped high-performance concrete is preliminarily determined; the pre-tension of the high-strength bolt is designed; the nominal diameter of the high-strength bolt is high-strength. The bolt connection torque check is divided into two steps. First check the end of the bolt to see if there is a leak. Then perform a torque check and the check method is loose. There are two kinds of rebate method and tight method.

Loose buckle. The reel method is to mark the thin wire at the relative position of the bolt and the nut first, then loosen the nut about 30, and then use the check torque wrench to re-tighten the nut to the original position so that the thin line is coincident. The torque measured at this time should be 0.9. The tight-fitting method is to check the torque wrench to tighten the nut. When the nut and the bolt have just measured a slight relative rotation angle, the final tightening torque check of the 0.9 high-strength bolt connection pair shall be after the final screwing 4 . Within 24 L. its ill! Ll3 is, V retracting bolts, the final end is 0 to 4, and the lt pre-tension loss has been largely completed. The high-strength bolt pre-tension is close to the design pre-stress. If the time is too long, the high-strength bolt coupling torque coefficient changes, which affects the accuracy of the inspection.

Do a good job in construction, inspection record 3. Re-inspection data of high-strength bolt connection pair; test data of joint plate anti-slip coefficient; initial and final tightening torque; 1 test data of tightening check torque. Apply torque wrench and check torque wrench calibration. Correctly record the high-strength bolt connection pair re-twisting torque of each node. Final torque check record.

After the high-strength bolt connection is passed the final screw inspection. Greasy stitching and painting are required.

1!1254.95 steel structure fabrication and installation procedures 8.

2! . 82 railway steel bridge high-strength bolts are currently being constructed.

He Wei 1975, male, graduated from Tianjin Urban Construction College in 1997, majoring in building materials, engineer, Shanxi Academy of Building Research, Taiyuan, Shanxi, 31

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