Waterproof concrete

Waterproof concrete (water-permeable concrete) has the property of being almost impermeable to water and has a correspondingly limited water penetration depth. In order to be able to meet these criteria, the concrete must correspond to a certain composition and compaction. The water cement value - that is, the ratio of cement and water - and the addition of certain concrete admixtures help to minimise water absorption.

More about waterproof concrete

Application:

Waterproof concrete is mainly used for components that are contaminated by pressurized water, such as components that border directly on the ground.

The

WU guideline specifies detailed requirements for planning and execution for water-impermeable concrete structures. Waterproofness describes the limitation or prevention of water penetration through concrete. Attention is paid to the penetration through joints, construction joints, predetermined crack cross-sections and cracks. This applies with regard to pressurized or non-pressurized water, temporarily accumulating or non-accumulating water, and soil moisture.

As a rule, waterproof

constructions alone cannot be described as watertight.

Structures made of waterproof concrete should be planned with simple and unambiguous load transfer. This avoids the formation of separation cracks.

Instructions for the professional construction of waterproof concrete:

• maximum free fall height: 1m (otherwise there is a risk of segregation at the foot of the wall)
• individual fill layers = 30 to 50cm
• the top concreting layer on walls must be recompacted
• Joint surfaces should be roughened
• Subsequent treatment of the concrete surface immediately after completion, by means of measures that reduce the residual or forced stresses as low as possible remain
• when precast walls are installed, the precast shells must not show any cracks
• Walls must be raised 30mm
• before the core concrete is applied, the insides must be pre-wetted, fill layers usually have a height of 50cm
• The waterproof concrete must be raised evenly in the entire concreting section for all walls, the manufacturer specifies
• the speedHorizontal working joints may only be placed at the level of floor slabs and ceilings
• The walls must be protected from vibrations as long as the core concrete is not sufficiently hardened
• Start and end times of pre-wetting, unloading of the truck mixer and concreting must be carefully documented 

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