HDPE geomembrane is also known as high-density polyethylene impermeable geomembrane. It's a kind of waterproof material, the raw material is high-molecular polymer. The main components are 97.5% of HDPE and 2.5% of Carbon black/anti-aging agent/anti-oxygen/UV absorbent / stabilizer and other accessory.
It is manufactured via triple co-extrusion technique by the most advanced automatic equipment which is imported from Italy.
Yingfan geomembranes all meet or exceed US GRI and ASTM standards. Its main function is anti-seepage and isolation.,so the installation of HDPE geomembrane liner is very important.
HDPE geomembrane installation process plays an important role in the waterproof and anti-seepage projects. We, Shanghai Yingfan Engineering Material Co.,LTD, have our own professional installation team to provide onsite installation services, with more than ten years experiences. So I hope this guide can really help you.
This guide introduces the installation method of HDPE geomembrane. Through this guide, you will better know how to install HDPE geomembrane and help you save time and labor.
Generally speaking, HDPE geomembrane installation process as follows:
1) Preparation for installation
2) On-site treatment
3) Preparation for laying HDPE geomembrane
4) Laying HDPE geomembrane
5) Welding HDPE geomembrane
6) Quality Inspect
7) Repair HDPE geomembrane
8) HDPE Geomembrane anchorage
9) Protective measure
Let me introduce the installation process of the geomembrane in detail below:
1. Preparation for installation
1.1 Prepare a flat area around the site (size:larger than 8m*10m ) for material unloading and cutting.
1.2 Unload the geomembrane carefully.Put some wood board at the edge of the truck and roll the geomembrane from the truck via manually or machine.
1.3 Cover the membrane with some other waterproof cover,below the pad empty.
2. On-site treatment
2.1 The laying base should be solid and flat. There should be no roots, rubble, stones, concrete particles, steel bars, glass shards, etc. that may damage the HDPE geomembrane .
2.2 Even up the bottom and side slope of the tank,tamp the surface with machine because the tank will stand tremendous pressure after water impoundment.To the soil of bottom and side slope,it must have sufficient capacity to withstand the water pressure to avoid the wall deformation due to the water pressure. The surface should be tamped.If allowed,concrete structure should be better.(As below pic.)
2.3. Hollow out anchoring groove (size 40cm*40cm) around the water tank for the fixation of HDPE geomembrane.
3. Peparation for laying HDPEgeomembrane
3.1 The surface should reach the design and quality requirement.
3.2 The quality of HDPE geomembrane and welding rod should reach the design and quality requirements.
3.3 Unrelated persons are not allowed to go into the installation site.
3.4 All the installers should wear pass and shoes which without damage to HDPE geomembrane.No smoking in installation site.
3.5 All the tools should be handled gently.Hot tools are not allowed to touch HDPE geomembrane.
3.6 Take protective measures to installed HDPE geomembrane.
3.7 We can not use the tools which may cause mechanical damage during the transfer process.Uncontrolled expansion methods are not allowed and handle with care.
4. Laying HDPE geomembrane
4.1 Unfold the HDPE geomembrane on flat area and cut the material to the need profile.
4.2 Man-made damage should be avoided during the laying process.The geomembrane should be laid smooth and minimize drape.Select the laying direction reasonable to decrease joint force.
4.3 Deformation of HDPE geomembrane should be obligated about 1%-4%.
4.4 All the explored HDPE geomembrane should be compressed via sandbags or other heavy objects to prevent geomembrane windblown.
4.5 The outdoor laying construction of HDPE geomembrane should be above 5 °C, and there is no rain or snow-free weather below 4 winds. When laying the geomembrane, the weld seam should be minimized. Under the premise of ensuring the quality, the raw materials should be saved as much as possible, and the quality can be easily ensured.
4.6 Measure: measure the size for cutting;
4.7 Cutting: Cutting according to actual size needs; the lap width is 10cm~15cm.
5. Welding HDPE geomembrane
5.1 Weather condition:
(1) Temperature:4-40℃
(2) Drying condition ,no rain or other water
(3) Wind speed ≤4 class/h
5.2 Hot welding：
5.2.1 The two HDPE geomembrane should be overlapped at least 15cm.The membrane should be adjusted and decrease the drape.
5.2.2 The welding area should be cleaned and ensure no water,dust or other sundries.
5.2.3 Trial welding: Test welding must be performed before the welding work is carried out. The test welding shall be carried out on the sample of the impervious material provided. The length of the sample shall not be less than 1 m and the width shall not be less than 0.2 m. After the test welding was completed, three 2.5 cm wide test pieces were cut to test the tear strength and the weld shear strength.
5.2.4 Welding: The geomembrane is welded using automatic crawl type double rail welding machine. An extrusion hot-melt welder shall be used where the double rail welding machine can not work. It's matched with the welding rod of the same material with geomembrane.The welding process are as follows: adjusting the pressure, setting the temperature, setting speed, joints inspection, geomembrane loading into the machine, start the motor.There shall be no oil or dust at the joints, and there shall be no debris, condensation, moisture and other debris in the lap joint surface of the geomembrane. Must be cleaned before welding.
5.3 Extrusion welding；
(1)The two HDPE geomembrane should be overlapped at least 7.5cm. The welding area should be cleaned and ensure no water,dust or other sundries.
(2)Hot welding can not damage the HDPE geomembrane.
(3)Welding rod must be clean and dry.
Hot welding
Extrusion welding
During welding process,to prevent HDPE geomembrane windblown,we will lay and weld at the same time.Before welding,clean the welding area.The wheel of welding machine should also be cleaned.Adjust the parameter before welding.Keep the welding machine running with uniform speed.Check the welding seam after Completely cooled.
6. Quality inspect
6.1 Self-check:Check and record each day.
6.2 Check all the welding seam,welding dot and repair area.
6.3 After installation,some small bump phenomenon are allowed.
6.4 All the hot welding seam must pass destructive test,the test is like:adopt tensile machine to cut and peel,the base material been destroyed while the welding seam are not allowed to be destroyed.
6.5 Air pressure detection: When using automatic crawl type double rail welding machine, the air cavity is reserved in the middle of the weld, and the air pressure testing equipment should be used to detect the strength and air tightness. After the construction of a weld is completed, both ends of the weld cavity are sealed, and the air chamber of the weld is pressurized to 250 kPa with a gas pressure detecting device for 3-5 minutes, the air pressure should not be lower than 240 kPa.And then at the other end of the weld,when the opening is deflated, the barometer pointer can be quickly returned to the zero side as qualified.
7. Repair HDPE geomembrane
During laying process,any defects or destroyed geomembrane must be repaired to avoid influence to waterproof function.
7.1 Small hole can be repaired by extrusion welding,if the hole is larger than 6mm,we should patch the material.
7.2 Strip area should be patched,if the ending of strip area is sharp,we will cut it to circular before striping.
7.3 The geomembrane should be grinded and clean before striping.
7.4 The patch material should be the same with the final product and be cut to circular or ellipse.The patch material must larger than the border of defect at least 15cm.
8. HDPE Geomembrane anchorage
Anchorage groove (size:40cm*40cm*40cm),pull the geomembrane into groove with U sharp and fix it with sandbag or concrete.
9. Protective measure
To protect the HDPE geomembrane,we will adopt below methods:
9.1 Pave another geotextile upper the geomembrane then repave sand or soil.
9.2 Pave the soil or concrete and beautify.
We, Shanghai Yingfan Engineering Material Co.,LTD, have our own professional installation team to provide onsite installation services, with more than ten years experiences.Welcome to contact us for more information for HDPE geomembrane products and installation service.
Post time: Sep-28-2022