Bentonite strip is a combination of rubber cord and natural bentonite clay with stabilizing additives. In contact with water, it may expand to about 4 to 5 times its initial volume, ensuring in this way the retention of water in the vertical and horizontal construction joints and sealing any cavities of concrete, cracks, etc.
Bentonite Strip Application
Hydrophilic strip is applied to reinforcing concretes in all groundwater and retaining of water areas. It is suitable for retaining water, at the level of construction joints, for structures, such as tunnels, parking, tanks, foundations, etc.
Its main properties – easy to use, resistant to aging and more severe atmospheric conditions, resistant to mold and microorganisms, does not contain harmful substances.
The waterstop strip should be spread over the area of installation after cleaning and removal of all undesired objects. Then fix the bentonite strip in the middle of the construction joint with steel nails, each of 25 cm. If the laying surface is excessively rough, make a pressure on the hydrophilic strip with the palm of the hand, or with a hammer with a wide base, so that it suits to the roughness of the support. To join a strip along its length or at intersections, simply “cut & butt”, to form a continuous network. Do not overlap.
Bentonite strip must be positioned such that there are at least 7 to 8 cm minimum concrete covers. Moreover, it should be used only for resumption of casting and be in direct contact only with the concrete base. The formwork spacers must be positioned so as to be at a minimum distance of 7 to 8 cm from the strip.
Keep in mind that if the material comes into contact with water before the junction, it can swell remarkably. In this case, it must be changed. In the presence of water and a high content of salts, expansion is reduced, depending on the type and quantities of dissolved salts.