Small dosages are enough to produce high-performance hydrophobic and self-healing concrete!

At a dosage of 1 to 3 kg/m³ (depending on the thickness of the concrete section and the concrete strength class), Hidrofob Kristal turns water from a structure’s greatest enemy into the main activation mechanism for its long-term protection.

What is HIDROFOB KRISTAL?

A powdered admixture certified as a water-resisting admixture in accordance with EN 934-2: T9, which is added directly to the dry constituents of the concrete before mixing, i.e. onto the aggregate conveyor belt.

How does this “smart” mechanism work?

Once the concrete has hardened, the active ingredients remain dormant within the concrete matrix. Upon initial contact with water or water ingress, they react chemically with moisture and the by-products of cement hydration, forming insoluble needle-like crystals. These crystals physically seal the capillaries and microcracks in the concrete. If new cracks appear, the admixture is reactivated and produces the same effect.

What are the main benefits and where is it used?

Autonomous self-healing: Enables permanent bridging and sealing of cracks up to 0.5 mm wide within the concrete structure, without the need for external intervention.

Reliability in “white tank” systems: Ideal for buried and underground structures where no additional waterproofing is specified - foundations, underground car parks, tunnels, retaining walls, swimming pools, manholes, tanks and harbour structures.

Resistance to aggressive environments and compliance with EN 206: Prevents the ingress of water and aggressive substances (salts, chlorides and sulphates), reduces carbonation and increases concrete durability when exposed to frost and high CO₂ concentrations. By sealing the pores in the concrete, it can, in certain cases, also directly help meet the requirements for specific concrete exposure classes under EN 206 (such as classes XC1–XC4).

How have these properties been verified in the laboratory?

The effectiveness of Hidrofob Kristal at different dosages has been thoroughly tested and confirmed in the scientific paper by the ADING team entitled “Investigation of the Crack-Sealing Process and Reduction of Water Permeability in Self-Healing Concrete with Crystalline Admixtures”.

Comprehensive testing in accordance with European standards demonstrated the following results:

- Capillary water absorption (in accordance with EN 480-5 and EN 934-2): The admixture reduces capillary absorption by more than 50% compared with the control mix, in accordance with the requirements of EN 934-2, while testing under EN 480-5 shows a reduction of up to 31% in absorbed water in specimens previously exposed to water.

- Resistance to water penetration under pressure (in accordance with EN 12390-8): Cyclic testing under a hydrostatic pressure of 500 kPa confirms that the water permeability of the concrete continuously decreases with each subsequent cycle of water exposure as a result of progressive crystal growth within the pores.

- Compressive strength (in accordance with EN 12390-3) and crack sealing: In addition to increasing ultimate compressive strength by 5% to 7%, water-flow tests through a crack and visual monitoring confirmed a drastic reduction in leakage after just 14 days and complete crack sealing after 28 days of exposure to water.

With a minimal dosage of 1 to 3 kg/m³ of concrete, you provide watertight, durable and active protection for your structure.

Hidrofob Kristal Technical Data Sheet

Watch the video on how it works and how to apply it

Read the full scientific paper