Unlike calcium chloride — the traditional cement accelerator — calcium formate is completely chloride-free. This is critical in reinforced concrete and tile adhesive applications where chloride ions would cause corrosion of embedded steel reinforcement. Calcium formate complies with EN 934-2 requirements for chloride-free concrete admixtures.
Calcium formate accelerates the hydration of Portland cement by increasing the concentration of calcium ions in the pore solution and accelerating the dissolution of C₃S (tricalcium silicate) — the primary strength-forming phase in cement. This leads to faster formation of calcium silicate hydrate (C-S-H) gel, resulting in higher early compressive strength at 1 and 3 days without significantly affecting 28-day strength.
Technical specifications
| PARAMETER | SPECIFICATION | TEST METHOD |
|---|---|---|
| Purity (as Ca(HCOO)₂) | ≥ 98.0% | Titration |
| Appearance | White crystalline powder | Visual |
| Moisture content | ≤ 1.0% | Karl Fischer |
| Heavy metals (as Pb) | ≤ 10 ppm | ICP-OES |
| Chloride content | ≤ 0.01% (100 ppm) | Ion chromatography |
| Bulk density | 800–1,000 g/L | EN 1097-3 |
| pH (10% solution, 20°C) | 6.5–7.5 | pH meter |
| CAS Number | 544-17-2 | |
| Molecular Weight | 130.11 g/mol | |
| HS Code | 2915.12 |
Applications
- Tile Adhesive & Grout — Dosage 0.5–2% by dry cement weight. Particularly effective in C1/C2 class polymer-modified tile adhesives.
- Dry-Mix Mortar — Used at 0.5–1.5% in floor screeds and repair mortars to achieve early strength for foot traffic.
- Concrete Admixture — Used as a non-chloride accelerating admixture compliant with EN 934-2. Typical dosage 0.5–2% by cement weight.
- EIFS & External Render — Added to external insulation and finish systems base coat and adhesive mortars to improve early strength and adhesion to substrate.
Key properties
- Chloride-free — safe for reinforced concrete and steel-frame applications, no rebar corrosion risk
- High purity 98% — low impurity level ensures consistent performance batch to batch
- Compatible with PCE and HPMC — can be used in the same dry-mix formulation without antagonistic effects
- No plasticising effect — does not reduce mortar stiffness or tensile bond strength
- Chloride-free in line with EN 934-2 requirements — meets European standard for concrete admixtures (non-chloride accelerator)
- Easy to handle — free-flowing powder, dustless grades available, low hygroscopicity at normal humidity
Usage and recommendations
| Application | Dosage (% by cement wt) | Effect |
|---|---|---|
| Tile adhesive (C1/C2) | 0.5–1.5% | Faster set, improved early bond strength |
| Floor screed / repair mortar | 0.5–2.0% | Earlier foot-traffic strength |
| Concrete admixture | 0.5–2.0% | Accelerated early compressive strength |
| EIFS base coat | 0.3–1.0% | Improved adhesion and early hardening |
Packaging
Available in 25 kg multi-wall paper bags.
Storage and shelf life
Store in a cool, dry place away from moisture. Shelf life 24 months from production date in sealed original packaging. Calcium formate is slightly hygroscopic — reseal bags after use.