1 The Paradox of Solids and the Age of Concrete
Sika CureHard LI has a higher density (~1.16 g/cm³) and solids content than C² Hard™. In the case of wet concrete, the high density of the product makes diffusion difficult.
Research Context (Key Difference).
The penetration (6 mm) declared in the CureHard LI documentation was achieved at the moisture content of the concrete 0,7%. This level of moisture is only found in concrete several years old, which acts like a "dry sponge.".
Penetration of C² Hard™ (3.2 mm) was measured on concrete 28-day (Moisture 3-5%), where the pores are naturally filled with water, which places higher demands on the chemistry.
Simulation of Penetration Depth (mm)
*The graph takes into account differences in the moisture content of the test substrate.
Estimated Penetration in Time
| Age of Concrete | CureHard LI | C² Hard™ |
|---|---|---|
| 28 days (3-5% MC). | 1 - 2 mm | 3.2 mm (Measured) |
| 1 year | 2 - 3 mm | 5 - 6 mm |
| 5 years | 4 - 5 mm | 6 - 8 mm |
| 10-15 years (0.7% MC). | 6 mm (Measured) | 8 - 10 mm (Estimated) |
2. C² Hard™ vs Sikafloor LI (Standard Lithium)
Integrated Hydrophobization
C² Hard™ contains Methyl silicate (Methylsiliconate), which actively repels water (pearling effect). Sika CureHard LI is a standard lithium silicate - it thickens, but does not have a built-in hydrophobic barrier.
Reduced Surface Tension
The C² Hard™ formula contains compounds that reduce the surface tension of liquids. This allows penetration into micropores that standard lithium silicate with a higher surface tension will not reach.
Active Stain Protection
Thanks to its hydrophobic component, C² Hard™ provides protection against the penetration of liquids (oils, juices) much faster than standard solids, which take time to "seal" the concrete with crystallization.
Full vapor permeability
Despite its hydrophobic properties, the C2 structure remains diffusion-open. The concrete "breathes," which prevents the top layer from peeling off under water vapor pressure.
Gloss Quality
The C2 (C² Hard™ + C² Seal™) system is optimized for polishing. Standard lithium silicates often require a longer curing time before achieving a high gloss finish.
Anti-slip
Improves coefficient of friction. Meets stringent ADA and ASTM C1028 standards (>0.60 SCOF), ensuring safety even in wet conditions.
3. comparison of concrete hardener chemistry
Sikafloor® CureHard LI vs C² Hard™: Active Ingredients Analysis
| Product | Type of active lithium | Concentration of the active ingredient | Functional additives |
|---|---|---|---|
| Sikafloor® CureHard LI |
Silicic acid, lithium salt (Standard Lithium Silicate) |
5 - 10% | No additives that activate the chemical reaction |
| C2 Hard |
Silicic acid, lithium salt + Potassium Methylsiliconate |
3 - 7% (lithium silicate) + 1 - 5% (activator) |
Hydrophobizing additive Actively improves penetration and repels water |
4. water absorption test (Karsten Tube)
The graph shows the effectiveness in reducing water absorption in concrete after application.
With the addition of hydrophobic, C² Hard™ immediately reduces capillary absorption. Sika's standard lithium silicate CureHard LI takes a long crystallization time to seal pores, and never achieves the "repelling" effect of water.
Reduction in Water Absorption (% relative to control).
5 Full Comparison Statement (Head-to-Head)
Updated data including hygienic approvals and performance parameters.
| Parameter / Category | C² Hard™ (Advanced Lithium) | Sika CureHard LI (Standard Lithium) |
|---|---|---|
| A. Certification and Security | ||
| Hygienic Certificate of PZH |
CERTIFIED BY PZH
|
NO PZH CERTIFICATE
|
| Food Safety |
NSF Certification (Approved)
|
No specific data available |
| Hydrophobic Properties | YES (Active ingredient) | NO (Compaction only) |
| B. Application Technology and Economics | ||
| Application Process | "No-Rinse" (No rinse). | May require rinsing with heavy application |
| Waste Management | No alkaline wastewater | May occur with heavy application |
| Performance (Coverage Rate) | 12 - 15 m²/L | ~ 6 - 10 m²/L (According to technical sheet). |
| Full response time (Sealing) | 7 - 14 Days | Standard (Slower) |
Material Economy (m² from 1 liter).
The higher performance of C² Hard™ means lower material cost per m² of flooring.
Increase in Abrasion Resistance
Direct comparison of hardness growth (excluding polished Super Hard for readability of the scale).
