Sikafloor® CureHard-24

1-part sodium silicate clear surface hardener, dust proofer and densifier for concrete

Sikafloor® CureHard-24 is a high solids, one part, clear sodium silicate based liquid to harden and densify fresh or hardened concrete. Sikafloor® CureHard-24 reacts to bind the free cement within the concrete substrate to improve the mechanical performance.

Usage

Packaging

10 kg container

Advantages

Colour

Clear liquid

Product Details

Chemical base


Sodium silicate water dilution

 

Shelf life


12 months from date of production

 

Storage conditions


The product must be stored properly in original, unopened and undamaged packaging, in dry conditions at temperatures between
+5 °C and +30 °C. Protect from frost.

 

Density


~1.15 kg/L (at +27 °C)

 

Solid content by weight


~20 %

System structure


Hardener / Sealer: 1–2 coats

Abrasion resistance


50 mg or 81.5 % increase in abrasion resistance compared to untreated sample

(C (0.70) concrete according to EN 1766) (Taber Abraser, H-22 Wheel, 1000 g / 1000 cycles)

 (EN 5740-1)

 

Resistance to impact


60 Nm (class III: ≥ 20 Nm)

(EN 6272-1)

Sample (MC 0.40) concrete according to EN 1766

 

Tensile adhesion strength


4.8 N/mm2

(EN 1542)

Sample (MC 0.70) concrete according to EN 1766

 

Penetration depth


5.5 mm(EN 1504-2)

Sample (MC 0.70) concrete according to EN 1766

 

Water absorption


w = 0.03 kg·m-2·h-0.5

(EN 1062-3)

(on a substrate w > 1 kg·m-2·h-0.5)

 

Application

Ambient air temperature


+5 °C min. / +35 °C max.

 

Relative air humidity


100 % max.

 

Substrate temperature


+5 °C min. / +35 °C max.

 

Waiting time / Overcoating


Where 2 coats are required, to ensure maximum densification, the second coat can be installed 2–4 hours following the first.
Allow previous coats to become tack free before applying additional coats.

Temperature

Time

+5 °C

~3.5 hours

+10 °C

~3 hours

+20 °C

~2 hours

+25 °C

~1.5 hours

Times are approximate and will be affected by changing ambient conditions particularly temperature and relative humidity

 

Drying time


The surface is touch-dry after 2 hours at +20 °C.
Maximum sealing and hardening effect achieved after ~7 days at +20 °C.

 

Applied product ready for use


Substrate temperature

Fully serviceable

+10 °C

~24 hours

+20 °C

~18 hours

+30 °C~10 hours

Note: treated concrete surface must not be wetted for the first 3 days at least. This could lead to efflorescence.

Note: Times are approximate and will be affected by changing ambient and substrate conditions. 

Consumption


0.15–0.25 kg/m2 per coat 
This figure is theoretical and does not include for any additional material required due to surface porosity, surface profile, variations in level and wastage etc.

 

Yield


4–7 m2/kg per coat

This figure is theoretical and does not include for any additional material required due to surface porosity, surface profile, variations in level and wastage etc.

SUBSTRATE QUALITY


Fresh concrete ≥ 7 days

The curing period (≥ 7 days) must be designed so that the areas near the surface achieve the structural strength and impermeability required for durability of the concrete, and corrosion protection of the reinforcement. Strength development is closely connected to the concrete composition, fresh concrete temperature, ambient conditions, concrete dimensions and the curing period required is influenced by the same factors

Hardened / old concrete
Surfaces must be sound, open textured, clean, free from frost, laitance, surface water, oils, grease, coatings, all loosely adhering particles and other surface contaminants. If in doubt apply a test area first.

 

SUBSTRATE PREPARATION


Fresh concrete

  1. The concrete must be prepared by power or manual floating / tamping techniques and be cured with water spray, blankets or plastic sheets for at least 7 days.

Hardened / old concrete

  1. The substrate must be prepared by high pressure water cleaning or by ride-on cleaning machines. Allow to dry prior to application.
  2. All dust, dirt, loose and friable material must be completely removed from all surfaces by brush and / or vacuum before application of the product.

 

APPLICATION


IMPORTANT

The chemical reaction between Sikafloor® CureHard-24 and the concrete causes the rate of water-tightness to increase gradually.

 

IMPORTANT

The maximum sealing and hardening effect occurs after a minimum of 7 days.

 

IMPORTANT

Gloss of the treated surface gradually increases between 30 to 90 days after application depending upon cleaning frequency.

 

  1. Apply Sikafloor® CureHard-24 in a continuous film using a high volume low pressure spray unit.
  2. Scrub material into the surface with a soft bristle broom or floor-scrubbing machine (min. 30 minutes), until the material begins to gel and becomes slippery.
  3. Wet the material slightly with a water spray and rework it into the surface for another 10 to 20 minutes.
  4. After about 20 minutes, the material will return to a gel, rinse the floor and remove any excess material using a squeegee, wet vacuum or mop.
  5. On porous, rough-textured or broom-finished surfaces, a second coat Sikafloor® CureHard-24 is required.
  6. For large surfaces and higher placing rates, ride-on cleaning machines can be used to place, brush in and remove the excess material from the surface.

 

The product can be used in combination with Sikafloor® CureHard GL.

 

CLEANING OF TOOLS


Clean all tools and application equipment with water immediately after use.
Hardened / cured material can only be mechanically removed.

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