Basement reinforcement technology

1 scope

This technology is applicable to reinforced concrete floors, basement wall reinforcement.

2 construction preparation

2.1 materials and equipment:

2.1.1 steel bars: factory certificate, required for mechanical property test. Special circumstances such as when the brittle fracture occurred during processing, the need for chemical composition test. Bars should be no old rust and oil.

2.1.2 wire: use of 20~22 wire (wire) or galvanized iron wire (wire). Wire cutting length to meet the requirements.

2.1.3 control mortar for concrete pads, plastic cards, a variety of hook or pole, and so on.

2.1.4 tools: steel hooks, crowbar, wrench, and tie racks, trolleys, wire brushes, chalks, rulers, etc.

2.2 operating conditions:

2.2.1 according to the location of the construction site plan provisions, the steel pile site clean and neat. Ready for wood, classified and piled up in the reinforcement sequence and will clean up the rust.

2.2.2 checking reinforcement level, type, shape, size and quantity is identical in design drawings and processed ingredients.

2.2.3 when the construction site when the water table is high, and must have drainage and rainfall measure.

2.2.4 familiarity with drawing paper, determine the order bars interspersed in place, and working with the trade as well, such as formwork, pipes, waterproof construction and relations binding reinforcement, construction methods, as well technical disclosure.

2.2.5 under basement waterproofing construction plan (using the post method or stick construction), the finished floor waterproof layer under and before the floor reinforcement layer; template around the finished floor (finished or build protective walls, water-proof). When external wall of basement waterproofing method when finished in reinforced masonry before lashing wall to protect the wall, water-proof and protection.

3 operational processes

3.1 process:

Steel line → games → tie bottom and steel rebar to use parts → tie walls

3.2 steel line: according to the drawing indicates the spacing of bars, calculate the floor number of actual need of reinforcement, generally bar near the bottom edge of the template that the template is 5cm, pop-up bar at the floor line of position (including the Foundation beam reinforcing steel bar line).

3.3 tied to Foundation and Foundation beam reinforcing steel bar

3.3.l pop-up steel line of position, bedding sheet lower reinforcement. According to floor forces, decided which direction the lower reinforcement steel bar below, the General Pu cross bars, then a long steel bar.

3.3.2 when reinforcement, close to the outer two lines intersect each lashing point, intersection point can be located in the Middle Cross banding, biaxial strength of steel rebar intersections must be completely binding. Such as CIS should be staggered change direction, or character buckles, but must ensure that the bar is not displacement.

3.3.3 placing mortar base plate concrete cover pad, the pad thickness is equal to the thickness, distance per 1M plum blossom display. Foundation base plate of thick or large amount of Foundation beam and plate steel, placed distance can be reduced, even mortar pad to use iron instead.

3.3.4 floor beams, subparagraph can be binding, and then fitted, or according to the beam line of position the in-place tie.

3.3.5 when base plate using double-layer bars, after you tie the lower bars, put bar stools or bar bracket (spacing to about 1M a) and stool placed on a horse in both horizontal and vertical direction positioned reinforcement, bars from top to bottom order and tie clasp with floor lower reinforcement.

3.3.6 floor reinforcement such as assembling connector, lap length and lap steel position, the construction requirements, rebar lap at both ends of the wire in the Center and fastened. Such as the use of welded joints, except as stipulated in the specification for welding of extracted sample should be outside, connector locations should also comply with the provisions of the code.

3.3.7 due to particularity of the Foundation and the Foundation beams, upper and lower reinforcement hamstring should comply with the design requirements.

3.3.8 according to play, location of columns line the walls, wall or column into the base reinforcing straps firmly, insert the base depth to meet the design requirements, throw in a length should not be too long, which measures should be taken to ensure rejection reinforced vertical at the top, not Askew, dumping, displacement.

3.4 Stud fastening:

3.4.1 pops up on the concrete walls and door location of opening lines, embedded reinforcing correction again, such as displacement, as stipulated in the negotiations dealt with seriously. Wall template should use "jump mode" in order to facilitate the steel construction.

3.4.2 tied 2~4 vertical bars and draw horizontal bar signs, then tied at the chest and lower two transverse reinforcement position and draw vertical bar symbol. General cross bars, vertical bars, so tied up tied after the vertical bar cross bar. Horizontal spacing and location of reinforcement shall conform to the design requirements.

3.4.3 stud to two-way reinforcement, cross point-by-point all steel banding, its length and location to meet the requirements of the design drawings and specifications.

3.4.4 should tie spacing between double-row steel support or reinforcement, with fixed spacing of bars. Φ or φ 8 6 available support or reinforcement steel production, space 1M, to ensure that the distance between the double-row steel.

3.4.5 with wire on the outside of the stud should be tied to the mortar blocks, to ensure that the thickness of the protective layer.

3.4.6 to ensure the door hole height is correctly positioned, in the hole on the vertical bar to draw elevations. Door hole according to the design requirements of steel banding, anchored into the wall length should comply with the design requirements.

3.4.7 the anti-seismic structural reinforcement and anchoring length of the connection point shall be according to the design requirements for banding. As the first layer of longitudinal steel bars into the basement wall depth; end walls, external walls of anchorage length of junction, banding should pay attention to.

3.4.8 installed in conjunction with other types of embedded pipe, hole, its location, elevation shall meet the design requirements.

4 quality criteria

4.1 project:

4.1.1 the variety and quality of the steel, welding, flux of brands, properties and use of steel plates, you must comply with the design requirements and the relevant provisions of the standards. Imported steel before welding, chemical composition inspection and weld test must be completed, comply with the relevant requirements before they can weld.

4.1.2 the bar surface must be clean, with a granular or flaky old rust, rust pitting of steel after, according to the original specifications is strictly prohibited.

4.1.3 reinforcement sizes, shapes, sizes, quantity, spacing, the anchorage length, connector set, you must meet the requirements of specification for design and construction.

4.1.4 mechanical properties of welded joints, steel welding special requirements must be met.

4.2 Basic project:

4.2.1 binding reinforcement missing buckle, loose quantity shall not exceed the secured debit 10%, and should not be set.

4.2.2 hook should be correct, lashing fittings shall conform to the provisions of the code, lap length is not less than the specified value.

4.2.3 made of grade ⅰ reinforcement Stirrups, which shall conform to the design requirements, hook angle and straight length should comply with the provisions of the code.

4.2.4 no transverse to the welded cracks and burns, uniform welding package. Bent joints shall not exceed 4 °, offset joints reinforced axis shall not be greater than 0.1d and less than 2mm.

4.2.5 arc weld surface, no dents, welding, and joints crack, blowhole, slag and the undercut. Connector size allowable deviation must not exceed the following requirements:

4.2.5.1 tied along the Joint Center's longitudinal displacement less than 0.5d, bent connector is not greater than 4 °.

4.2.5.2 rebar joint axis offset of less than 0.1d and less than 3mm.

4.2.5.3 seam thickness of not less than 0.05d.

4.2.5.4 weld width not less than 0.1d.

4.2.5.5 weld length not less than 0.5d.

4.2.5.6 bent joints is not greater than 4 °.

4.3 allowable deviation, as shown in table 4-6.

Rebar embedded parts installation and position tolerance value table 4-6

Project tolerance (mm) test method

Welding ± 10

Lashing ± 20

2 frame width and height ± 5

3 skeleton length ± 10

Welding ± 10

Lashing ± 20

Spacing ± 10 ' at both ends, the point, take the maximum value

Distance ± 5 a point to take the maximum value

Beginning 6 steel bending displacement 20

Center line 5

High levels of differential +3-0

Basis of ± 10

Reinforcement beams and columns of 8 ± 5 foot check

Wall plate ± 3

5 finished product protection

5.l rebar piled up at a specified location, with a wood mat in order to prevent deformation of steel, rust, oil.

5.2 Stud binding should take a temporary shelf, no pedal step on the bars.

5.3 properly exposed waterproofing layer of protection around the base to avoid steel bar cutting.

5.4 chassis when the upper and lower reinforcement and support horse Chair tied to a solid, prevent tread deformation during operation.

5.5 non-free cutting steel.

6 quality problems to be noticed

6.1 embedded reinforcement displacement of wall and column: main bar of wall and column reinforcing and base plate fixed upper and lower reinforcement tie firmly to ensure accurate. If necessary, additional steel welding electrodes welding in prison. Before concrete pouring should be free to check trim.

6.2 exposed tendons: walls and columns reinforced cement mortar around every 1M and bandage the wire blocks (or plastic card).

6.3 lap length is not enough: when binding each connector should be standard, check whether the lap length comply with design and code requirements.

6.4 splices location error: beams, columns and walls when there are joints, ingredients processing, construction drawings should be drawn in advance according to the drawing, indicate the number bar mix order and avoid the reinforcement of the maximum bending moment.

6.5 binding joints with welding does not stagger: welding processing of steel, when assembling in the field, the welding head to stagger the lap position. So when machining material, where from the end of lap length range without welding.

7 quality records

This standard shall meet the following quality records:

7.1 steel quality certificate or test report form.

7.2 mechanical properties of reinforcing bars reexamination report.

7.3 import steel chemical composition and solderability test report the test report. Made in steel in the process of brittle fault, poor weldability and mechanical properties significantly abnormal, chemical composition inspection report.

7.4 test of welded joints.

7.5 welding, flux factory certificate.

7.6 bar section for quality inspection and assessment of information.

7.7 steel cover engineering acceptance record.