Composite Geomembrane Anti-seepage Construction Specifications and Quality Acceptance Methods
Basic (support layer)
1. The foundation is compact and even and flat. The dry density of the soil foundation shall not be less than 1.4t / m3, and the uniformity error shall not exceed 10%.
2. The soil foundation affected by groundwater should be laid on a flat foundation with a layer of 2cm sand or a layer of non-woven fabric.
3. For the soil foundation not affected by groundwater, clear the debris such as surface tree roots that can easily pierce the geomembrane, and lay it directly, but you need to set up a “reverse valve” or exhaust under the membrane, drainage measures.
4. Anchor grooves shall be provided at the upper end.
Seam connection method
One cloth one film edge bonding method: (1) film heat welding, film cloth, cloth KS adhesive bonding (2) film, film cloth, cloth KS adhesive bonding (3) KS film glue bonding
Two cloths and one film edge joining method: (1) film thermal welding, film cloth, cloth KS glue bonding (2) film, film cloth, cloth KS glue bonding % Or more, meeting the requirements of the construction technical specification SL / T225-98 (the joint strength must be greater than 80% of the strength of the base material and the fracture must occur on the base material)
Seam quality inspection method
Visual inspection method: Supervision Engineer Forum http://bbs.job2299.com/ When selecting the film and film thermal welding, observe all seams, if the weld seams are transparent, uniform, no wrinkles, no voids, strong hand peeling Can be regarded as qualified. When the selection film and the film are bonded by KS adhesive, the adhesive width is 10cm, and the joints must not have warpage, protrusions, degumming, holes, looseness, lack of glue, and the damage occurs on the adhesive after peeling, and the non-adhesive surface.
On-site inspection vacuum method: Use a set of equipment including suction cups, vacuum pumps, and vacuum machines. When testing, brush the part to be tested, apply the soapy water, put on a suction cup, press tightly, and evacuate to a negative pressure) 0.02 ~ 0.03MPa, and turn off the air pump. Watch for the 30s, and see if there are soap bubbles in the transparent cover on the top of the suction cup and whether the vacuum gauge is lowered. If there is a leak, it should be remedied. Inflatable method: Welding seam is double strip, leaving about a 10mm cavity between the two. Seal the two ends of the section to be tested, insert the air needle, inflate to 0.05 ～ 0.2MPa (select after the film), observe for the 30s, and observe the vacuum gauge. If the air pressure does not decrease, it indicates that there is no leakage, then connects the suture grid, otherwise repair it.
Sampling test method: Take a sample of about 1000 square meters for the tensile strength test, the strength is required to be not less than 80% of the base material, and the fracture of the sample must not be at the joint, otherwise the quality of the joint is unqualified. Note that the quality inspection of joints is often a combination of the above methods to judge and control the quality.