Admixture Dosage Rate Calculator

Advanced calculator for dosing superplasticizers and other chemical admixtures by weight of cement or per cubic meter with flexible units density adjustment batch scaling tolerance bands hydration limits and clear step by step guidance for ready mix labs precast yards and jobsite crews ensuring consistent performance and traceable records with validation hints and explanations

Input Parameters

Cement per batch will be computed as volume × cement content.

bwoc = by weight of cement
Typical range 1.02–1.15 kg/L.
How the calculation works
  1. Determine cement in the batch: cement_mass = cement_per_batch_kg or volume × cement_content.
  2. Apply the dosage:
    • % bwoc: admixture_mass = cement_mass × (percent ÷ 100).
    • mL per kg: admixture_volume_L = cement_mass × (mL_per_kg ÷ 1000).
    • L per 100 kg: admixture_volume_L = (cement_mass ÷ 100) × L_per_100kg.
  3. Convert mass/volume using density: volume = mass ÷ density, mass = volume × density.
  4. Multiply by number of batches for totals.

Always confirm manufacturer recommendations and conduct trial mixes to verify performance.

Results
Within recommended band
Metric Per batch Total (1 batch)
Cement (kg) 350.000 350.000
Admixture mass (kg) 2.800 2.800
Admixture volume (L) 2.667 2.667
Recommended band (based on % bwoc)
Band Mass per batch (kg) Volume per batch (L)
Min 0.400% 1.400 1.333
Max 1.500% 5.250 5.000
Note: If using dosage units other than percent, the band comparison still uses the % bwoc values you provided to check suitability.
Assumptions and Tips
  • Density is product specific; consult the technical datasheet for accurate conversion between mass and volume.
  • For plant dosing, calibrate flow meters or pump counts to liters required per batch.
  • When batching by truck volume, verify actual yield and adjust cement content accordingly.
  • Trial mixes should confirm slump, workability retention, and strength development at the selected rate.
FAQs
1) What does % bwoc mean?

It stands for percent by weight of cement. A 1% rate equals 1 kg of admixture mass per 100 kg of cement. The tool converts between mass and volume using density.

2) Can I enter mL per kg instead of percent?

Yes. Choose mL per kg and provide the value. The calculator multiplies by cement mass and converts mL to liters. You can still set a recommended percentage band for checks.

3) What density should I use?

Use the product datasheet. Many water-reducing agents have densities around 1.02–1.15 kg/L, but specialty products may differ. Accurate density is required for mass↔volume conversion.

4) How do I use it for multiple batches or trucks?

Enter the number of identical batches. The results table reports both per-batch requirements and the total for all batches.

5) Can this estimate compliance with manufacturer limits?

Enter the recommended minimum and maximum percentages. The badge indicates whether your selected dose falls within that band for the current cement mass.

6) Does it account for water in the admixture?

No. If water content from the admixture affects water-cement ratio or slump, adjust your mix design accordingly using your internal procedures.

Important Note: All the Calculators listed in this site are for educational purpose only and we do not guarentee the accuracy of results. Please do consult with other sources as well.