How to install the HDPE geomembrane?

Construction Process of HDPE geomembrane

1. Determine the laying plan.

First of all, it is necessary to clarify the location and purpose of laying, determine the required materials and tools, and calculate the area of geomembrane.

2. Ground preparation.

a. Dig an anchoring trench in advance and fix the geomembrane here. The trench is about 50-100cm depth.

b. Ground preparation must be carried out before laying the geomembrane. The ground should be flat, dry, and free of weeds to ensure that the geomembrane adheres closely to the ground.

3. Lay geomembrane.

a. Specify the position of the membrane in place, immediately use sand bags for temporary anchoring, and then check whether the overlap width of the membrane meets the requirements of about 100mm. If adjustment is needed, make timely adjustments to fully prepare for the next process.

b. The overlap width of the seams between membranes is generally not less than 10cm. Usually, the welding seam arrangement direction is parallel to the maximum slope, that is, arranged along the slope direction.

4. Geomembrane welding.

When laying the geomembrane, it is necessary to connect the geomembrane to ensure that the joints will not leak. Connection methods generally include welding with welding machine and gluing.

Attention:

a. During the welding process, it is necessary to ensure that there is no debris within the overlap range of the weld that will affect the welding quality.

b. The overlap width of the weld should be maintained, which should be sufficient for destructive testing.

c. Except for repairs and capping, there should be no horizontal joints with a slope greater than 1:10.

d. The weld at the bottom of the slope should extend at least 1.5 meters from the foot of the slope to the bottom of the site.

5. Press the geomembrane tightly.

After the connection and laying are completed, the geomembrane needs to be properly compacted to enhance the adhesion to the ground and prevent problems such as hollowing of the geomembrane.

6. Pressure test

Double-track hot-melt joints must be tested using non-destructive pressure testing methods.

a. Pressure testing equipment must include an air pressure pump, pressure pipes, pressure gauges and pressure input devices.

b. To seal both sides of the test seam, insert a needle or a pressure input method into the air channel created by the double-track hot-melt seam equipment. The air pump is connected to the air input device, and the air channel maintains a pressure of 200kPa.

c. After reaching a steady state, the air channel pressure is observed and the final results are recorded. If the air pressure drops less than 20kPa, the joint at the other end of the pressure gauge must be opened to reduce the pressure and detect blockage of the air channel. If the pressure cannot be returned to zero, it means that the joint is blocked and the joint has failed the non-destructive test. If the pressure returns to zero, the seam passes the test.

7. Repair.

After the laying is completed, the connections and damaged areas need to be repaired to ensure the integrity and tightness of the geomembrane.