1. The elastic line first pops out the center line of the steel beam in the paving area. The center line of the beam is the control line of the fixed main position of the paving floor slab. The center line of the main beam controls the overlap width of the steel beam overlapped by the floor slab, and determines the weld position of the penetration welding between the floor slab and the steel beam. The center line of the beam will determine the welding position of the secondary studs in penetration welding. Because it is difficult to observe the specific position of the flange of the secondary beam after the floor slab is laid, the center line of the secondary beam and the width of the flange of the secondary beam are bounced back on the central line of the main beam. When fixing bolts, the center line of the secondary beam and the width of the flange of the secondary beam should be bounced back on the floor slab of the secondary beam.
2. Layout and blanking according to the overlap length required by the drawing design, the position, spacing and span size of the main and secondary beams, can be divided into standard cross-section steel plate layout; non-standard cross-section steel plate layout; standard joint layout; individual joint layout; profiled steel plate number, material list, etc. The overlap size of profiled steel sheet and main girder in this project is not less than 50 mm.
3. Lifting:
1) When the profiled steel sheet manufacturer supplies, the profiled steel sheet shall be packed and transported to the site in units of installation units, and the profiled steel sheet shall be stacked and laid neatly according to the layout provided by the manufacturer. 2) Before lifting profiled steel sheets, the shape, size, number of blocks and location of profiled steel sheets should be checked according to the design construction drawings. After confirming that the ingredients are correct, the profiled steel sheets should be lifted and stacked in stacks among the construction sections according to the installation sequence and progress of the main structure. The stacking should be scattered in strips. When the profiled plate is hoisted on the beam, it should be lowered at a slow speed, and rough hoisting action should be avoided. 3) In loading, unloading and installation of profiled steel sheets, it is strictly forbidden to use wire rope to bind and hoist directly. Soft suspension rope should be used or rubber sheet should be added at the corner of the contact between the wire rope and the plate or pad wood should be used under the steel sheet. Sufficient fulcrums should be provided for transportation and stacking in order to prevent deformation. The lifting should be smooth and not inclined to avoid slipping and injuring people. 4) When the profiled steel sheets are stacked in bundles, they should span multiple steel beams and place a single span between the two beams, attention should be paid to the support width at both ends, so as to avoid falling accidents caused by dumping. 5) Construction is prohibited when the wind speed is greater than or equal to 6m/s. The profiled steel sheets that have been dismantled should be re-bundled. Otherwise, the profiled steel sheets may be blown up by strong wind, which may cause safety accidents or damage to the profiled steel sheets.
4. installation
1) Bending deformers should be corrected before laying. 2) The top surface of steel beams should be kept clean, damp-proof and wet-proof, and wet-painted. 3) Before installing profiled steel plate, the position line of profiled steel plate should be marked on the beam. When laying profiled steel sheets, the waveform grooves at the ends of two rows of profiled steel sheets should be aligned. After hoisting in place, the phase plate starts with the springing-up line of the steel beam itself, and the single piece is in place along the laying direction. After the control line, the seam of the plate should be adjusted appropriately. 4) The position and straightness of the board should be adjusted in strict accordance with the requirements of drawings and specifications. The maximum deviation of the straightness of the board is 10 mm for a single span, and the cross-section of the board should be less than 5 mm. The main girder can be connected only after passing the inspection. 5) The laying direction of profiled steel sheet should be perpendicular to the direction of minor beam. The main beam should be disconnected and the overlap should not be less than 50 mm. 6) The laying of irregular panels is based on the layout of steel beams on the spot. The centerline of steel beams is laid out, and then the control line is laid out. The area of profiled steel plate to be laid in practice is obtained, and then the layout is carried out according to the width of profiled steel plate. After that, the profiled steel plate is laid out and cut. The profiled steel plate is pre-assembled on the ground on the platform, and it is found that there are parts with loose occlusion and imprecise occlusion that need to be adjusted. Laying according to the actual layout, connecting and fixing.
5. Installation of baffles, side-closing boards and side-closing boards to prevent slurry leakage during concrete pouring of floor slabs, to keep the floor deck tightly sealed and the size of the four-sided structure. The thickness of baffle, edge-closing plate and edge-closing plate is not less than 4 mm. The construction drawings are as follows:
6. Welding Fixation
1) The groove bottom of each sheet of profiled steel plate should be fixed with 16 mm diameter welding nails and steel beams. The average maximum distance between the welding joints is 20.3. Welding material should penetrate profiled steel plate and have good welding with steel beam material. If the penetrating studs are directly planted on the steel beams through the profiled steel sheet, the studs can replace some of the welding points mentioned above.
2) Welding with steel beams includes not only supporting steel beams at both ends of profiled steel sheet, but also secondary beams between spans. If the welding current of bolts is too large, which causes the profiled steel plate to burn through and loosen, the welding joints should be supplemented beside the bolts.
3) Opening and cutting on site: For the cutting of profiled steel sheets on site, such as bevel edge, cutting angle, super-long, hole-retaining and some irregular surfaces, plasma cutting machine should be used to avoid destroying the coating treatment on the surface of steel sheets. If oxygen acetylene is used for cutting, zinc-rich anti-rust paint should be applied on the edge of the cutting edge to avoid rust; when construction of hydropower and ventilation pipelines is carried out, the construction personnel of profiled steel sheet shall cut holes. After cutting, the hole should be protected as required.
4) After positioning the profiled steel plate, the cutting line is ejected and cut along the line. The position of cutting line should be consulted in detail with the floor plan and layout plan, and checked; general holes should be left after concrete pouring as far as possible before cutting, such as pre-opening in the vertical direction of plate rib is harmful to the groove rib of profiled steel plate, it must be reinforced according to the regulations. The reinforcing measures are detailed in the drawing, as shown in the construction sample of opening and reinforcing
5) The profiled steel plate is installed, straightened, compacted and spot welded firmly according to the drawing.
The requirements are as follows:
(1) Corrugations are aligned so that reinforcing bars can pass through the waves.
(2) overlap with the beam at the groove for welding;
(3) Each groove must be soldered firmly, each groove must not be less than one soldered joint, and the diameter of the soldered joint must not be less than 25px.
(4) After the profiled steel plate is laid and straightened and fixed, the locking device should be used in time to prevent the separation of the profiled plate bite due to the stacking of construction materials or personnel traffic.
After installation, construction waste should be cleaned in time before installation of reinforcing bars, and the cut edges should be collected and stacked centrally on the ground.
7. Reinforcement engineering can be carried out only after the acceptance and acceptance of profiled steel sheets and bolts for some reinforced concrete floor slabs are qualified. The concrete construction technology of composite slab is basically similar to that of pure concrete slab. When pouring concrete, because the project adopts unsupported profiled steel sheet as the slab formwork, it should be careful to avoid the excessive accumulation of concrete and the impact caused by pouring concrete when pouring concrete.