Tunnels and Mines

Gemite offers a wide range of high performance solutions for structural mortars and concrete waterproofing, even on negative side and when high water levels are present.

Gemite cementitious coatings and systems provide exceptional protection, and non-hazardous formulations are compliant with all health and safety guidelines.  They cure without any hazardous odor, can be safely applied in public areas, and are very user friendly.


Surface Preparation

Shotblasting, sandblasting or scarifying are used for surface preparation, to obtain a minimum CSP #3 per ICRI (International Concrete Repair Institute) surface profile.

Clean the reprofiled surface using 34 MPa (5,000 psi) pressure water.

Corrosion Protection – Fibre-Prime

Clean reinforcing steel using mechanical abrasion – “white metal” surface is NOT required.

Polymerized cementitious rustproofing, with migrating corrosion protection technology, is applied to any exposed reinforcing steel (rebar) and protects all surfaces of partially “buried” steel.

Spray-Con WS ST Premix or Concentrate

Applied using wet process shotcrete to construct the tunnel retaining or structural walls.

Concentrate is locally mixed with Portland cement and aggregates to reduce material cost.

Spray-Con DS ST Premix or Concentrate

Concentrate is locally mixed with Portland cement and aggregates to reduce material cost.

Hand Applied Mortar

Fibre-Patch OV

Hand applied Fibre-Patch OV is used for small section (volume) repairs in restoration projects.

Advantages of Gemite shotcrete

  • High strength
  • Low permeability
  • Excellent adhesion
  • Low shrinkage
  • Very Low rebound (Spray-Con WS ST)
  • Excellent spraying rheology in overhead applications (Spray-Con WS ST)


Tunnels and mines often suffer from water leaks requiring negative side waterproofing and waterproofing materials must be able to be applied to damp surfaces and at high RH.

Gemite cementitious coatings are ideal for application onto ‘green’ concrete and provide decades of effective resistance to water ingress, chlorides and other aggressive chemicals.

Fibre-Patch WP (water plug)

Stop active leaks are stopped by hydraulic plug or polyurethane injections.

Cem-Kote CW Plus

Cem-Kote CW Plus is a crystalline waterproofing slurry applied over existing concrete.  It is not flexible and needs three day wet-cure, to develop water tightness.

Advantages of Cem-Kote CW Plus Bearing Bonded Topping

Dual Waterproofing Action

Cem-Kote CW Plus combines Crystalline (reactive) + Membrane Waterproofing

Result is an extremely Fast Activation – a few days, rather than weeks that are the norm for an old-style crystalline waterproofing. It can be used for negative and positive waterproofing as a brush-or spray-applied slurry.

Longer Open Time + Easy Application

Cem-Kote CW Plus has a much longer open-time = Easier + Faster Application

Cem-Kote CW Plus is very easy to spray apply using conventional spray equipment, peristaltic or positive displacement, due to its excellent rheology and virtually no rebound.

Other crystalline materials have quite short “working time” after mixing, and higher ambient temperatures further shorten set times, resulting in very trying application.

Cem-Kote Flex ST

Highly flexible polymer modified cement coating are then applied to provide negative side waterproofing.

Cem-Kote Flex ST requires air dry curing for three days and is highly flexible, providing efficient crack bridging.

Advantages of Cem-Kote Flex STBearing Bonded Topping

Insensitive to Moisture & Humidity

Cem-Kote Flex ST can be applied on Wet Substrate & at High Humidity

Cem-Kote Flex is completely insensitive to surface moisture and high humidity. It stops water penetration from the Negative side and prevents debonding due to vapor condensation resulting in high capillary pressures at concrete-membrane interface.

Polymer coatings are very sensitive to moisture in concrete, surface moisture, high relative humidity and water vapor penetrating from behind or below concrete (below grade).  Most polymer coatings require 25 mm (1”) depth of concrete to be dried, or application of moisture barrier layer, prior to application – extremely expensive procedures.


Cem-Kote Flex ST is “breathable” = Allows Water Vapor to Escape from concrete

Polymer membranes act as vapor barriers, preventing water vapor escape – resulting in de-bonding problems.

Flexibility + Crack Bridging

Cem-Kote Flex ST delivers crack bridging, augmented by Reinforcing Fabric HD

Polymer coatings (epoxy, vinyl-esters or flexibilized epoxies) are non-flexible, without (or limited) crack bridging capability.

Easy + Fast Application

Cem-Kote Flex ST is Easily & Quickly Applied without Special Equipment

Polymer coatings are “sticky”, and the tools and equipment are difficult to clean, even with expensive organic solvents.  Application of polymer coatings has to be carried out in a very narrow “application window”, which increase the applied cost.