“White tub” – permanently active crystallization with Radmyx™

The construction of waterproof structures, i.e. structures without waterproofing ("white tub" according to the German "Weiβe Wanne") has been a practice all over the world for several decades, and in the last two decades it has become a common practice in Croatia. So "white tubs" are structures in which the reinforced concrete structure, in addition to its load-bearing function, also performs the function of waterproofing. In order to ensure the function of this "white tub" system, it must be ensured that the structure is built of waterproof concrete (VDP 3 according to HR EN 12390-8). All horizontal and vertical working joints, as well as expansion joints and all pipe penetrations through the structure must be sealed in an appropriate manner. Therefore, the quality of construction of such structures is greatly influenced by the concrete technology itself, the installation and care of the concrete, the type and method of solving the joints, and the construction without cracks.

What is Radmyx and how works

Radmyx™ is a crystallization-based concrete additive in powder form that was designed many years ago to provide a self-sustaining waterproofing product that provides 100% protection of concrete structures throughout the life of the concrete structure. Radmyx™ achieves this through its unique formula using its ability to regenerate crystal growth

Active particles Radmyxu™ react with cement particles in concrete and form insoluble fiber-like crystals. These crystals fill the cracks, pores and capillaries in the concrete and thus prevent the passage of water through the concrete. Active particles Radmyx™ permanently they become an integral part of the concrete and remain dormant in the concrete. If these particles subsequently come into contact with water (in the event of a crack in the concrete), they are reactivated and continue their crystal growth through the concrete structure.

This ability Radmyx™ to be activated every time it comes into contact with water, guarantees that the concrete will have 100% protection against water throughout the entire life of the concrete structure, since with Radmyx™ Concrete has the ability to heal itself on a daily basis.

Since Radmyx™ is added to concrete as a pure concentrate, unlike many other similar products that are added to concrete mixed with cement and sand, a mixture with Radmyx™ has a much higher number of crystals within the concrete structure itself and therefore has a greater ability to continuously produce crystals in the future, and thus is Radmyx™ superior to other products. Radmyx ™ is a product certified according to Norma EN 934-2, table 9-according to which concrete additives for waterproofing are specified. It meets VDP 3 class. In addition to Radmyx™ makes concrete waterproof and also improves other properties of concrete such as:

• Increases the compressive strength of concrete
• Reduces capillary absorption of water
• Prevents chloride diffusion
• Reduces initial surface water absorption
• Protects reinforcement from corrosion
• Extends the lifespan of structures

Key advantages

• Multipurpose – used as an additive in fresh concrete, coating, plaster and spreading powder (when mixed with cement and sand). Used for new concrete structures as well as for the rehabilitation of old ones.
• Simple – installation is simple and efficient, saving time and money. No additional waterproofing is required. Shortens construction time.
• Low risk – unlike membranes that can be damaged, delaminate, etc., there is no need to protect the concrete from damage when backfilling foundation walls.
• Reactive – remains dormant in the concrete until it comes into contact with water, when it is reactivated each time and closes cracks. It closes microcracks up to 0.4 mm.
• Permanent – permanently remains an integral part of the concrete. It is not subject to aging and deterioration. It is not necessary to renew it in the future, nor any other waterproofing.
• Safe – Radmyx ™ is non-toxic and safe even for use in drinking water tanks. Prevents the penetration of harmful substances into concrete (water, chlorides, sulfur). Resistant to positive and negative hydrostatic pressure. The crystals act deep within the concrete structure, not just on the surface.

Areas of application

Radmyx ™ is the right choice for all buildings that are located below ground level and that are in contact with water. These are all basement surfaces such as foundation slabs and walls, basements, underground garages, elevator shafts, concrete pipes and sewers, drainage channels, water tanks, swimming pools, aquariums, cooling towers, wastewater collectors, dams, tunnels, etc.

Dosage and application of Radmyx™

Dosage Radmyx™ is very simple, because as a concentrate it has a fixed dose and is not measured according to the amount of cement in the concrete. Being in concentrated form also makes it easier to add because a smaller amount is added per 1m³ of concrete compared to other products sold as mixtures. An additional advantage is that the product, in addition to large packages, also comes in biodegradable bags designed for 1m³ of concrete, which greatly simplifies and speeds up installation. The manufacturer's Recommendations provide guidelines for concrete production technology, installation and concrete care after installation. Radmyx ™ can be added to the dry mix at the concrete plant before adding water or directly to the fresh concrete at the construction site.

In order to create a quality "white bath", in addition to quality production, installation and maintenance of waterproof concrete, quality insulation of working and expansion joints is of key importance. Depending on the degree of moisture load on the structure, there are several solutions, such as: for lower loads, Quellmax swelling tapes, it is recommended Quellmax Plus tape with a special patented coating that, if the tape is placed in water, provides a delay in swelling for up to 72 hours. For higher loads, the following are recommended: CEMflex VB sheets that, in addition to forming a physical barrier to the passage of water, have a special coating on them that, if water reaches the sheet through the joint, the coating on the sheet releases crystals and displaces the water to the edge of the wall, providing 100% protection to the working joint and protecting the external reinforcement from water. For extremely high water pressure loads, injection tubes are used, which are subsequently filled with a special filling that protects the working joint from the passage of water. In certain situations during design and construction, it is necessary to apply a combination of the above materials in order to achieve a permanent and safe solution for sealing weak points of the building.

All expansion joints should be sealed using expansion tapes, and the choice of type depends on the requirements of each individual building. All penetrations through the reinforced concrete structure for installation pipes must be adequately sealed using swelling tapes that are wrapped around the pipes in one or two rows.

Note: Radmyx ™ added to concrete with adequate solution of working and expansion joints makes Radmyx crystallizing "white tub" a safe and permanent solution.         

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