When non-expandable damage causes water leakage, such as cracks or problematic joints, the system you use is an external waterstop, and the waterproof barrier is located in the external part above the fault area. The composite geomembrane waterstop consists of a multi-layer specific location support system placed on cracks or joints in possible open areas. The component is one or several independent layers, the type and structure of which are the total width and estimated displacement of the head, crack or joint.
The composite geomembrane can include an anti-puncture layer to avoid too rough board; a support layer/sacrificial layer, which is suitable for preventing the waterproof casing from invading cracks or joints under the conditions of maximum opening and maximum water head; and drainage layer. The waterproof layer is placed on the bracket and is independently anchored without the aid of the bracket. This layer is generally made of geosynthetic material, which is suitable for covering the joints. The lateral area of the cracks or the areas where the joints may open is at least 200 to 250mm.
Composite geomembrane is a kind of composite material, which is composed of anti-seepage layer and anti-puncture geotextile. The minimum free total width (the net distance between the peripheral seals) of the waterproof geocomposite is generally 400mm. The elongation at break of the geomembrane exceeds 230%, and the elongation at break of the thermally bonded geotextile is about 50%. Therefore, the geotextile component must be opened at least 200mm before breaking. When the seam is opened by 200mm, the geomembrane will still maintain its impermeability and elasticity. This is because if the geomembrane is broken, it needs to be opened by 900mm or more, and under all conditions, the support system is designed to limit the geomembrane Strain. The above-mentioned dimensions related to the maximum elongation of the exposed waterstop exceed the magnitude of the actual estimated joint movement. On the contrary, the deformation of the traditional embedded waterstop is mainly based on the size of the central sphere; therefore, its maximum extension is one order of magnitude smaller than the extension of the external waterstop. When the external waterstop is adjustable, the embedded waterstop will not work.
