Steel bar weight deviation detection
Reason: According to the Code for Acceptance of Construction Quality of Concrete Structure Engineering (GB524-22), 5.2 Requirements of main control project in raw materials:
5.2.1 When steel bars enter the site, the mechanical properties and weight deviation of the specimens should be tested according to the current national standards, and the test results must conform to the relevant standards.
inspection quantity: determined according to the sampling inspection scheme of incoming batches and products.
inspection method: check the product certificate, ex-factory inspection report and re-inspection report.
Extended information:
Twenty-three construction technical points of steel bar project:
1. In order to ensure the steel bar materials, the varieties, properties and quality of steel bars used in the project must conform to the provisions of the construction specifications, and the quality certificate provided by the manufacturer must be obtained before entering the site. Tensile strength, yield strength, elongation and weight deviation per unit length should be tested when the raw steel bar enters the site.
2. After the finished steel bar enters the site, except for the routine re-examination project, it must be sampled by the quality inspection personnel to see if it meets the allowable deviation specified in the specification, and it can only be put into use after passing the inspection.
3. The materials, mechanical equipment and working conditions used for steel bar welding must conform to the standards. After butt welding of steel bars, all welds shall be visually inspected.
4. In the process of steel binding, adhere to the principle of "seven prohibitions".
5. during the acceptance of steel bars, adhere to the principle of "five non-inspections".
6. Control the blanking and forming of steel bars.
7. Processing of various supporting steel bars used as positioning measures: the ends of steel bars shall be cut by toothless saws, and there shall be no "flash and burr". The exposed ends of steel bars shall be painted with antirust paint.
8. Vertical ladder bars: vertical ladder bars are made according to the spacing between horizontal bars, and the spacing is ≯1.2m, so as to ensure the horizontal and vertical reinforcement, the wall section size and the thickness of the protective layer. Vertical ladder bars can replace vertical reinforcement, but they are one size larger than the design diameter.
when the story height is less than 4.m, three support ends are set at the top, middle and bottom of the vertical ladder lattice reinforcement, and one support is added for every 1m increase of the story height, and the ends are cut with a toothless saw and painted with antirust paint; After the vertical ladder bars are processed, they shall be packed according to the wall thickness and marked.
9. Horizontal ladder bars: According to the spacing of vertical bars designed in the drawings, the horizontal ladder bars are processed and fixed on the top of the wall to control the spacing of vertical bars. Check the position of horizontal ladder bars before pouring concrete on the wall and roof to avoid being false.
1, according to the specifications and spacing of column main reinforcement, set the internal and external positioning stirrup frames to control the displacement of reinforcement.
11. stirrup processing requirements: the processing standards are listed on the site, and detailed samples are turned over before processing, which are clearly indicated in front of the steel bars processed respectively. Stirrups are hung on steel pipes for inspection.
12, steel binding adopts model guide and listing system. The technical disclosure of steel bar binding (detailed figures) is directly hung on the operation surface to guide construction and facilitate inspection.
13. When steel bars are bound, tie the knot inward, and press the tail wire inward. All walls and columns shall adopt splayed buttons, and the steel bars at the four corners of embedded columns shall use pocket buttons. Horizontal hanging wire, vertical hanging wire, control verticality.
14. The cushion blocks for controlling the protective layer of steel bars shall be shaped plastic cushion blocks or marble and concrete cushion blocks, and the cushion blocks shall be arranged in plum blossom shape. Control the acceptance and binding of the cushion block, especially strengthen the control of the cushion block of the bottom reinforced protective layer of the beam.
further clarify the binding position of the cushion block in the technical disclosure. Before using the pad, it must be carefully selected, stored in different specifications, and marked, indicating the specifications and the parts to be used. When binding, check them one by one to ensure that the binding is firm.
15. Control the position and spacing of column stirrups with a number of skin poles, and use them as the basis for binding and fixing inspection and acceptance.
16. When shuttering the doors and windows, set the positioning bars for fixing the door formwork, and the positioning bars shall be welded on the additional U-shaped iron, not on the stress bars, and the U-shaped iron shall be bound on the main reinforcement.
17. Consider the location of reserved holes for water, electricity, equipment, etc., and try not to cut the steel bar. The electric box is welded on the additional steel bar, which is firmly installed, and shall not be welded on the main reinforcement, and the additional steel bar shall not be welded on the stress reinforcement, but shall be tied on the main reinforcement.
18. The machined straight thread cone head shall be inspected by special mould, and the straight thread joint shall be inspected by torque wrench after connection, and it shall be marked after it is qualified.
19. Before pouring concrete, the vertical bars of walls and columns should be protected by plastic pipes or wrapped tightly with colored cloth strips and plastic strips, and when pouring concrete, the contaminated steel bars should be wiped with cloth or cotton silk in time.
2, adhere to the pay-off twice. After the floor formwork is finished, pay-off shall be conducted once, and then pay-off shall be conducted for the second time after the plate reinforcement binding is completed, and beam slab concrete can be poured only after it is accurate.
21. locate the rebar at the construction joint of the floor, place the stubble wood square between the two skin rebar and the protective layer of the lower iron rebar, and support it with the rebar horse stool.
22. After the steel bar is bound and formed, it is forbidden to trample, especially the negative reinforcement parts; When pouring concrete, set up the operation track. Vibrating rods are not allowed to touch steel bars, and designated persons shall correct the position of steel bars at any time.
23. After concrete pouring, assign personnel to be responsible for adjusting the position of steel bars in time, correcting the displacement of steel bars caused by concrete pouring, and cleaning the mortar stuck on steel bars in time with wet cloth.
Baidu Encyclopedia-Code for Acceptance of Construction Quality of Concrete Structure Engineering