Bituminous geomembrane is a type of geomembrane that is made from asphalt and is used in a variety of applications, including landfill liners, pond liners, and canal liners. Some advantages of using bituminous geomembrane include: Durability: Bituminous geomembrane is highly resistant to UV radiation, punctures, and tears, making it a long-lasting option for lining projects. Chemical resistance: Bituminous geomembrane is resistant to a wide range of chemicals, including acids and alkalis, making it suitable for use in harsh environments. Waterproofing: Bituminous geomembrane is an effective barrier against water, making it useful for lining projects that need to prevent the infiltration of water. Low permeability: Bituminous geomembrane has a low permeability rate, meaning it is resistant to the passage of water and other fluids. Easy to install: Bituminous geomembrane is flexible and easy to install, making it a popular choice for lining projects.

The subgrade requirements for a bituminous geomembrane include: being free of rough elements that may damage the geomembrane, vegetation, and organic plant matter; having level defects no greater than 5 cm under a 3-meter straight edge; having sufficient bearing capacity; having a slope of less than 1/1 for inclines of 8 meters or more to ensure proper holding of the geomembrane and eliminate the risk of slope sliding; and potentially having drainage under the geomembrane if there is a risk of water or gas being present.

The welding techniques used when installing bituminous geomembrane involve using a standard team of a welder and a helper, and specific equipment such as metal rolls of 10-15 kg for horizontal sections and 5 kg for slopes and specific points. Welding should not be done in the presence of water, but slight dampness is acceptable. The welding process involves brushing the seam areas, removing the silicone protective paper from the weld strip, cleaning mud traces, removing sharp stones, heating the edge between the two layers with a torch and rolling the layers together to create a continuous seam. The seam should be visually checked once it has cooled down, and a finishing operation, such as warming the edge between the two membranes to form a scarf joint, may be performed.

The standard quality control procedures when installing bituminous geomembrane include visual inspection, compressed air lance testing, vacuum bell testing, ultrasound testing, dielectric testing, and destructive testing. Visual inspection involves examining the width and quality of the weld and checking for the presence of a bitumen bead cover. Compressed air lance testing involves using a compressed air lance to highlight discontinuities in the seam. Vacuum bell testing involves applying a depression to a Plexiglas bell over the weld and observing for soap bubbles, which indicate air leaks and potential defects. Ultrasound testing involves emitting ultrasound on the surface of the weld and detecting intermediate echoes on an echograph screen to identify defects. Dielectric testing (considered to be above standard QC measures) involves testing the entire surface of the geomembrane waterproofing solution to detect specific passing defects or the scale of defects. Destructive testing involves sampling welds for tensile strength tests. Defective welds should be repaired with an additional layer of geomembrane, and the repair patch should be welded on its entire surface by rolling.