Waterproofing of water tanks and reservoirs made of concrete

RELATED MATERIALS

AQUAMAT Cement-based waterproofing slurry

AQUAMAT-ELASTIC Two-component, elastic waterproofing slurry

DUROCRET-PLUS Polymer-modified,fiber-reinforced repairing cement mortar

RAPICRET Fast-setting patching mortar

PLASTIPROOF Plasticizing/water reducing admixture for concrete

AQUAMAT-ADMIX Crystalline waterproofing admixture

 

 

I. NATURE OF THE PROBLEM – REQUIREMENTS

One of the most important issues that builders confront with while constructing concrete water reservoirs is waterproofing. The requirements, which must be satisfied, differ according to whether it is located above or below ground.

In the case of an underground reservoir, the waterproofing layer must:

  • Ensure that there is neither leakage of water from the reservoir nor any ingress of water from the surrounding soil.
  • Be strongly bonded to the walls of the reservoir, in order to withstand the negative pressures that develop when the reservoir is emptied and the water table of the urrounding soil is raised, even if this only occurs temporarily.

In the case of an above the ground reservoir, the waterproofing layer must:

  • Be effective in terms of having no leaks.
  • Have sufficient elasticity to withstand the expansion and contraction of the reservoir walls and floor, since these are exposed to temperature changes of the enviroment.

II. SOLUTION

An essential assumption for successful waterproofing is that the walls and floor of the reservoir are properly designed so that they are statically efficient to withstand the hydrostatic water pressure developed.

Underground reservoir

The internal surfaces of the walls and floor are coated with AQUAMAT, cement-based, brushable waterproofing slurry, which provides:

  • A uniform and continuous, totally waterproof membrane, which is characterised by high strength and strong bonding to the substrate in order to withstand negative pressure.
  • Strength and longevity due to the inorganic nature of the material.

Above the ground reservoir

The walls and floor are coated with AQUAMAT-ELASTIC, elastic, brushable waterproofing slurry. The membrane created is:

  • Totally waterproof.
  • Very durable and strongly bonded.
  • Long lasting.
  • Highly elastic in order to follow successfully the expansion and contraction of the substrate.

During construction of the reservoir’s concrete elements, the use of PLASTIPROOF, plasticizer-concrete waterproofing admixture, is recommended in either case. This should be added to concrete in the proportion of 0,2-0,5% of cement weight. Also AQUAMAT-ADMIX the crystalline waterproofing admixture in a proportion of 0,8-1,0 % by cement weight should be added.

III. APPLICATION

Preparation of the substrate

  1. Thorough cleaning of grease residues, deshuttering agents, dust, loose materials, etc. from the surface.
  2. Loose particles should be cleaned from existing cavities in the concrete.
  3. Form wires and distance pieces should be cut at a depth of 3 cm.
  4. Existing construction joints should be opened in a V-shape, towards the inside, along their entire length, at a depth of 3 cm.
  5. The surface of the above areas should be thoroughly dampened and filled with DUROCRET-PLUS polymer modified,fiber-reinforced repairing cement mortar. Alternatively, when fast work is necessary, RAPICRET fast-setting patching mortar can be used instead.
    DUROCRET-PLUS consumption: 25 kg for trearing a 30-40 m². surface (indicative consumption for a normal concrete wall).
  6. Intersections of the floor with vertical elements (concrete walls, columns), should be dampened and filled along their entire length with DUROCRET-PLUS polymer modified,fiber-reinforced repairing cement mortar (formation of a “groove” with a triangular cross-section having 5-6 cm sides). DUROCRET-PLUS consumption: 1,9-2,7 kg/m of “groove”.
  7. The entire surface of the substrate should be dampened well, but without creating any water puddles.

Application of waterproofing

Underground reservoir

  1. The content of a 25 kg bag of AQUAMAT is gradually added to 8,25 kg of water under continuous stirring, until a uniform brushable paste is formed. A low-revolution mixer (300 rpm) may be used for mixing.
  2. AQUAMAT is applied inside the reservoir, on the floor and walls, in 3-4 layers. As the depth of the reservoir and therefore the developed hydrostatic pressure increases, there is a requirement for more consumption of the material. Each layer should be applied after the previous one has dried. In order to avoid cracking, each layer should not be more than 1 mm thick.
    Consumption of AQUAMAT: 3-4 kg/m² in total.

Above the ground reservoir

  1. The content of the 25 kg bag (component A) of AQUAMAT-ELASTIC is added into the 10 kg of liquid (component B) under continuous stirring, until a uniform viscous mixture is formed, suitable for brush application. A low-revolution mixer (300 rpm) may be used for mixing.
  2. AQUAMAT-ELASTIC is applied inside the reservoir, on the floor and walls, in 3-4 layers. As the depth of the reservoir and therefore the developed hydrostatic pressure increases, there is a requirement for more consumption of the material. Each layer should be applied after the previous one has dried. In order to avoid cracking, each layer should not be more than 1 mm thick.
    Consumption of AQUAMAT-ELASTIC: 3-4 kg/m² in total.

IV. REMARKS

  • The ambient temperature during application of the material must be above +5ºC.
  • Consult the instructions for safe use and precautions written on the packaging.
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