Customized rental of construction steel formwork: How to ensure the installation accuracy of steel formwork?

1、 Preparation before construction
Material acceptance
Check the verticality deviation of the steel formwork to be ≤ 1.5mm/m, the gap between joints to be ≤ 0.5mm, and use an ultrasonic thickness gauge to randomly check the wall thickness tolerance to be ± 0.3mm
Bolt strength grade ≥ 8.8, matching nut pre tightening torque ≥ 200N · m
Establishment of measurement benchmark
The total station is used to set up the axis control network, with a plane position error of ≤± 2mm and an elevation error of ≤± 1mm
Set the double line control template boundary and inspection line with a spacing of 30mm for easy review
Prefabricated assembly testing
Ground pre assembly inspection of overall dimensions, correcting deviations in advance before hoisting
2、 Positioning and Support System
Control points, technical parameters, and execution standards
Basic positioning pre embedded with Φ 20 support rod @ 600mm, embedded depth ≥ 50mm
Support spacing: upright pole ≤ 1.2m, horizontal bar ≤ 1.5m, diagonal brace angle 45 °± 5 ° 6
Load preloading applied at 10kN/m ², simulated load deformation ≤ L/4009
3、 Seam and Connection Control
Seam sealing
3mm closed cell foam adhesive strip is embedded at the seam, and waterstop steel batten is installed outside
The corner adopts L-shaped connection angle mold, and the U-shaped card spacing is ≤ 300mm
Tightening standards
Φ 16 pull screw @ 450mm, torque wrench detection pre tightening force compliance rate of 100%
One column hoop shall be set every 600mm, and slant support @ 1500mm shall be added to the cantilever structure
4、 Precision calibration technology
3D detection
Laser leveling instrument controls verticality ≤ 2mm/m and flatness ≤ 3mm/2m
Ultrasonic rangefinder rechecking reserved hole position deviation ≤ 5mm
Dynamic adjustment
Correct layer by layer during pouring, with a deviation of ≤ 1.5mm at the upper opening of the lower formwork
When the temperature exceeds 30 ℃, thermal expansion compensation shall be carried out, and the compensation amount shall be calculated at 0.012mm/(m ·℃)
5、 Environmental and Process Control
Welding deformation prevention
Adopting skip welding technology to reduce thermal stress, welding current control:
Plate thickness δ ≤ 10mm: 120-160A
δ＞10mm：160-220A9
Humidity response
Stop welding operations when RH>85%, and cover the installed template with moisture-proof film
6、 Acceptance criteria
Specification basis for allowable deviation detection tools for testing items
Axis position ± 3mm total station GB50204-2025
Sectional dimensions+2/-3mm Vernier caliper JGJ162-2024
Adjacent board height difference ≤ 1mm 2m ruler JGJ74-2025
Joint gap ≤ 1.5mm, plug gauge GB/T50214-2024
Through the above control measures, the qualified rate of steel formwork installation accuracy can be achieved at ≥ 97%, and the qualified rate of concrete forming dimensions can be achieved at ≥ 96%.