Three-layer waterproofing membrane for the waterproofing of reinforced concrete components in contact with the ground, consisting of a bentonite waterproofing, a PE waterproofing system and a radon/root protection made of PE fabric.
The bentonite waterproofing is based on the natural clay mineral sodium bentonite, which is woven into a geotextile carrier fabric as granules or needled with it. It has an additive effect on plastic waterproofing. Only when the outer plastic layer fails does the activation of the bentonite occur, which occurs when the granules come into contact with the penetrating moisture. Due to the resulting swelling pressure in the bentonite, the waterproofing membrane seals towards the concrete with simultaneous contact pressure from the outside (e.g. due to soil, additional load). This state of hydration persists even when the waterproofing environment dries out. The two sealing levels are joined on the water side by a PE-coated fabric to protect against root penetration and as a radon barrier layer.
Compared to single-layer systems, multi-layer waterproofing membranes offer additional security against penetrating moisture and, thanks to the third layer, also offer protection against other influences. They can be installed horizontally and vertically below the site, usually without a fresh concrete composite. This means that the trams are also suitable for renovation work. Bentonite seals were developed in particular for water loads from damming leachate and pressing groundwater. While this technology has been anchored in earthworks, landfills and civil engineering for decades, it has only been used in recent years in the field of building waterproofing in contact with the ground as part of the so-called brown trough. The use of multi-layer bentonite waterproofing systems is also possible in flowing groundwater, as it is not possible to wash out the bentonite through the water-side plastic layer.
Source: bauwion
