Key points of inspection and acceptance after the installation of the Waterstop Bolt

Key points of inspection and acceptance after the installation of the Waterstop Bolt

As the core component of waterproofing and formwork fixation,the inspection and acceptance after installation should cover the three dimensions of"waterproof reliability,structural stability,and formwork compliance"to avoid leakage or wall quality problems caused by hidden defects,and the specific process and standards are as follows:

1.Inspection of foundation appearance and component integrity

Screw and waterstop inspection:check the Waterstop Bolt one by one for bending and thread damage(the thread must be complete,no broken wires or sliding wires);The welding part of the waterstop plate should be full without false welding and leakage welding(you can use a small hammer to tap the weld,and no crisp hollow drum sound is qualified),and the waterstop is perpendicular to the screw(deviation≤3°),without offset or tilt-if the position of the waterstop is more than 2cm away from the center line of the wall,it needs to be readjusted to prevent the failure of the waterproof section.

Supporting component inspection:Confirm whether the gaskets(usuallyΦ100×5mm steel plate gaskets)and double nuts outside the formwork on both sides are complete and installed in place,and the gaskets should be close to the steel pipe and the template,without hanging;The inner rod and connecting sleeve of the three-stage Waterstop Bolt should be tightly meshed and not loose(the connecting sleeve can be manually screwed,and no rotation is qualified)to avoid the screw failure caused by the connecting sleeve falling off during pouring.

2.Waterproof sealing performance inspection

Template inner seal inspection:focus on the inner gap between the screw and the template,the rubber sealing ring should be fully embedded in the template hole,without displacement or damage(the diameter of the sealing ring should be 2-3mm larger than the template hole diameter to ensure a tight fit);If waterproof tape is used,it is necessary to ensure that the tape is wound flat and there are no seam gaps to prevent concrete slurry from leaking out of the gaps to form a"screw hole leakage channel".

Protective inspection around the waterstop:If the wall steel bar is dense,it is necessary to confirm that there is no direct collision between the waterstop and the steel bar(spacing≥5cm)to avoid deformation of the waterstop caused by the extrusion of the steel bar;At the same time,check whether the surface of the waterstop is clean and free of oil and rust(oil stains will affect the adhesion between the concrete and the screw,and need to be cleaned with sandpaper or solvent).

3.Template positioning and flatness acceptance

Screw positioning deviation acceptance:check the screw spacing(transverse and longitudinal spacing deviation≤10mm)according to the construction drawings,and check the diagonal distance of adjacent screws with a tape measure,with a deviation of≤15mm;At the same time,check whether the screw is perpendicular to the surface of the template(measured with a right-angle ruler,the verticality deviation is≤2°)to avoid uneven local force on the template caused by the tilt of the screw.

Formwork flatness and verticality acceptance:

Flatness:Use a 2m ruler to close to the surface of the template,check section by section,the gap between the ruler and the template is≤3mm(can be measured by a feeler gauge),and there is no local bulge or depression;

Verticality:Use a wire hammer or laser casting instrument to check the verticality of the formwork,when the wall height is≤3m,the deviation is≤5mm;When the height is>3m,the deviation≤8mm to prevent the formwork from tilting due to the imbalance of screw fastening,which will affect the quality of wall forming.

4.Stress stability test and acceptance

Nut tightening force test:use a torque wrench to spot check the fastening torque of the screw nut(determined according to the diameter of the screw,such asΦ12 screw torque 25-30N·m,Φ14 screw 35-40N·m),the spot check ratio is not less than 10%,and each inspection batch is not less than 3,and the torque deviation≤±10%is qualified,to avoid insufficient force leading to formwork swelling during pouring,or excessive force leading to screw bending.

Overall support stability check:manual shaking of the formwork and steel pipe support,no obvious shaking is qualified;Check whether the oblique support at the top and corners of the formwork is firm,and whether the bottom of the support is cushioned with wood(to prevent the support from sinking)to ensure that the screw and the support system bear the pressure on the concrete side together,and there is no risk of single-point force overload.

5.Hidden project acceptance records

After all inspections and acceptances are passed,it is necessary to fill in the"Acceptance Record of the Hidden Project for the Installation of the Waterstop Screw",clarify the acceptance part,screw specifications,waterstop parameters,inspection items and results,and attach on-site photos(focusing on the welding of the waterstop plate,sealing parts,and the flatness inspection scene of the formwork),which shall be jointly signed and confirmed by the construction unit and the supervision unit before entering the next concrete pouring process;If the inspection finds unqualified items(such as leakage of welding of the waterstop and the flatness of the formwork exceeding the standard),it needs to be rectified and re-accepted until all of them meet the standards.