Waterproofing tunnels built in mining technique

The method for waterproofing tunnels with KÖSTER products is based on a combination of negative side waterproofing and a liquid applied crack bridging waterproofing compound. The waterproofing layers cannot be infiltrated and the water will not move laterally between the layers as with membranes. The system does not need drainage. No water is being drained off the surrounding soil so the water table is not affected.

This system is suitable for tunnels built with closed construction techniques. Flowing water is stopped by injecting KÖSTER KB-Pur IN 1 and afterwards permanently sealed with the elastic resin KÖSTER KB-Pur IN 2. Small leakages or whole walls which are being penetrated by water can be sealed with KÖSTER KD 2 Blitz Powder. To waterproof the entire surface from the negative side KÖSTER NB 1 Grey is applied to the dry and solid substrate. After KÖSTER NB 1 Grey has hardened the crack bridging coating KÖSTER CFR 1 is applied to the waterproofed and dry substrate. Finally the system is covered with another layer of concrete. The waterproofing is sandwiched between two concrete layers.

Always adhere to the specifications in the respective Technical Guidelines.

Heavy duty corrosion protection with Silicate Mortar or PSM

For the protection of concrete surfaces against acids the first step is to coat the surface with the negative side waterproofing KÖSTER NB 1 Grey or the faster version KÖSTER NB 1 “fast”. The acid protection itself is made with KÖSTER Silicate Mortar (also suitable for damp substrates) or KÖSTER PSM (suitable for dry substrates and easy to apply).
Where acid resistant tiles are to be applied KÖSTER Silicate adhesive can be used as a tile adhesive and KÖSTER Silicate Mortar is used for jointing the tiles.
Always adhere to the specifications in the respective Technical Guidelines.

Heavy duty corrosion protection with KÖSTER PSM

One example of the need for heavy duty corrosion protection against acidic fumes and condensate is the coating of industrial chimneys made of concrete or masonry.
 
For the restoration of concrete or masonry, the substrate is to be mechanically cleaned until a solid, unburdened substrate is achieved. The surface is primed with KÖSTER Polysil TG 500, which hardens the substrate and immobilizes salts.
 
Reprofiing is done with KÖSTER Repair Mortar NC. The surface is roughened in order to achieve a strong mechanical bond to the surface with KÖSTER PSM. 
 
KÖSTER PSM is applied as the protective layer against acids.
 
Always adhere to the specifications in the respective Technical Guidelines.

Corrosion protection of steel

The corrosion protection of steel is usually done with a two layer coating of KÖSTER Corrosion Protection, applied by brush or roller. The substrate preparation is carried out according to DIN EN ISO 12 944-4 (Sa 2 ½, RY5 > 50 μm).
 
If a crack bridging, flexible coating is required KÖSTER Corrosion Protection is to be coated with two layers of KÖSTER PUR-Bitumen.
 
In the case of extraordinary high acid impact (e. g. when underrunning the acid dew point) the entire coating is to be carried out with two layers of KÖSTER VE. In addition to that KÖSTER VE is suitable for covering edges, holes and screws prior to the application of KÖSTER Corrosion Protection.
 
Always adhere to the specifications in the respective Technical Guidelines.
 
Because corrosion protection on steel requires experience and should be analyzed case by case, please contact our technical consultants. They will be glad to answer your questions.