Is the weight deviation detection of steel bars a required inspection item?

The weight deviation detection of steel bars is a required inspection item.

Reason: According to the "Concrete Structure Engineering Construction Quality Acceptance Code" GB50204-2002 partially revised 5.2 Raw Materials

Main control project requirements:

5.2.1 Steel bars When entering the site, test pieces should be selected for mechanical properties and weight deviation inspection in accordance with the provisions of the relevant national standards. The inspection results must comply with the provisions of the relevant standards.

Inspection quantity: determined according to the incoming batch and product sampling inspection plan.

Inspection method: Check the product certificate, factory inspection report and on-site re-inspection report.

Extended information:

23 construction technical points for steel bar projects:

1. In order to ensure the steel bar materials, the variety, performance and quality of the steel bars used in the project must comply with According to the construction regulations, entering the site must have a quality certificate provided by the manufacturer. Raw steel bars entering the site must be inspected for tensile strength, yield strength, elongation and weight deviation per unit length.

2. After the finished steel bars enter the site, in addition to the regular on-site retest items, they must be randomly inspected by quality inspectors to see whether they meet the allowable deviations stipulated in the specifications. They can be put into use only after passing the inspection.

3. The materials, mechanical equipment, and operating conditions used for steel bar welding must comply with the standards. After the steel bar butt welding is completed, all welds must be visually inspected.

4. During the process of tying steel bars, adhere to the principle of "seven no-nos".

5. When accepting steel bars, adhere to the "five no-inspections" principle.

6. Control the cutting and forming of steel bars.

7. Processing of various supporting steel bars used as positioning measures: The ends of the steel bars must be cut with toothless saws, and there must be no "flash or burrs". The ends of the exposed steel bars should be painted with anti-rust paint.

8. Vertical ladder bars: Make vertical ladder bars according to the horizontal bar spacing, and set the spacing ≯ 1.2m to ensure the horizontal and vertical steel bars, the wall cross-sectional size and the thickness of the protective layer, and the vertical ladder bars. Ladder bars can replace vertical steel bars, but they are one size larger than the design diameter.

When the floor height is below 4.0m, three support ends are provided for the vertical ladder bars at the top, middle and bottom. One support is added for every 1m increase in floor height. The ends are cut with a toothless saw and Apply anti-rust paint; after the vertical ladder bars are processed, they are stacked according to the thickness of the wall and marked.

9. Horizontal ladder bars: According to the vertical bar spacing designed in the drawing, horizontal ladder bars are processed and fixed on the top of the wall. They are used to control the vertical bar spacing and are inspected before pouring concrete on the wall and roof. The position of the horizontal ladder bars should be avoided.

10. Set internal and external positioning stirrup frames according to the specifications and spacing of the column main bars to control the displacement of the steel bars.

11. Stirrup processing requirements: The processing standards are listed on the site, and detailed copies are made before processing, which are clearly displayed in front of the respective steel bars to be processed. The stirrups are suspended from the steel pipe to facilitate inspection.

12. The steel bar binding adopts the sample guide and tag system. The technical explanation of steel bar binding (detailed and specific figures) is hung directly on the operating surface to guide construction and facilitate inspection.

13. When tying steel bars, tie the knot inward and press the tail wire inward. Walls and columns should all use figure-shaped buckles, and the four-corner steel bars of concealed columns should use pocket buckles. Horizontal hanging wire, vertical hanging wire, control verticality.

14. The pads used to control the protective layer of steel bars should be shaped plastic pads or marble or concrete pads, arranged in a plum blossom shape. Control the acceptance and binding of pads, especially the control of pads for the protective layer of steel bars at the bottom of reinforced beams.

The binding position of the pads will be further clarified in the technical briefing. Pads must be carefully selected before use, stored according to specifications, and marked with specifications and usage parts. When tying, check them one by one to ensure they are securely tied.

15. Use dermal rods to control the position and spacing of column stirrups, and use them as the basis for inspection and acceptance of binding and fixation.

16. When setting up the door and window opening formwork, set the positioning ribs to fix the door formwork, and the positioning ribs should be welded to the additional U-shaped iron, and must not be welded to the stress-bearing ribs, and the U-shaped iron should be tied to On the main tendon.

17. When turning steel bars, consider the location of reserved holes for water, electricity, equipment, etc., and try not to cut off the steel bars. The electric box is welded to the additional steel bars, and the installation is firm. It must not be welded to the main bars, and the additional steel bars must not be welded to. Welded to the stress-bearing reinforcement, it should be tied to the main reinforcement.

18. The processed straight threaded cone head should be inspected with a special mold. After the straight threaded joint is connected, it should be inspected with a torque wrench. If it is qualified, it should be marked.

19. Before pouring concrete, the vertical bars of walls and columns should be protected with plastic pipes or tightly wrapped with colored cloth strips or plastic strips. When pouring concrete, they should be covered with cloth or cotton silk soaked in water in time. Wipe down contaminated steel bars.

20. Insist on releasing the line twice. After the floor formwork is completed, the laying out is carried out once, and after the slab steel bars are tied, the laying out is carried out a second time. Only when it is accurate can the beam and slab concrete be poured.

21. Position the steel bars at the construction joints of the floor slab. Use wooden squares to place them between the two steel bars and at the protective layer of the lower iron steel bars, and use steel horse stools to support them.

22. After the steel bars are tied and formed, no stepping on them is allowed, especially on the negative reinforcement parts; set up an operating horse track when pouring concrete. The vibrator rod is not allowed to touch the steel bars, and a dedicated person should be assigned to correct the position of the steel bars at any time.

23. After the concrete pouring is completed, assign a dedicated person to promptly adjust the position of the steel bars, correct the displacement of the steel bars caused by pouring the concrete, and use a wet cloth to promptly clean the mortar stuck to the steel bars.

Baidu Encyclopedia-Concrete Structure Engineering Construction Quality Acceptance Specification