PRELIMINARY PROPORTIONING · EUROPE

Build a trial mixture without pretending the calculator is a conformity checker.

Select the concrete context, enter the project limits you have actually verified, and inspect how water, cement and aggregates close the volume balance. If a project limit is left blank, the calculator does not invent one.

EN 206 context · national provisions apply

How to use this responsibly: exposure class is recorded for context only. The calculator does not automatically assign a code maximum w/c or minimum cement content. Enter those values only when you have confirmed them from the current national/project requirements.

Concrete requirements & verified limits

Separate the concrete description from the limits that actually control the project.

Strength class Exposure class (context only) Planning strength margin (N/mm²)Planning input, not an automatic EN 206 value. Trial free water-cement ratio Verified project max w/c (optional) Verified project min cement (kg/m³, optional) Design air content (%) Max aggregate size (mm) Consistence class Aggregate shape Coarse aggregate share % (blank = model start)

Material properties & water reduction

Use current supplier/laboratory values where available; defaults are only starting values.

Cement specific gravity Fine aggregate specific gravity Coarse aggregate specific gravity Use water-reducing admixture? Admixture dose (% of cement) Expected water reduction (%)Use trial/supplier evidence, not marketing maximums. Admixture specific gravity

PRELIMINARY TRIAL MIX

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Estimate material cost Estimate carbon impact

Planning mean strength-N/mm²

Used w/c-entered / verified cap

Starting water-kg/m³ · model estimate

Cement-kg/m³

Starting proportions per m³

Ingredient	kg/m³ / %	Absolute volume m³

Mass ratio (cement : water : fine : coarse) = -. A mass ratio is descriptive, not a project approval criterion.

Calculation trail

What to verify in the trial

Consistency and whether it remains workable for the intended transport and placement time.
Cohesion, bleeding and segregation resistance.
Air content where relevant, density/yield and actual batch volume.
Strength and every other performance property required by the project.
Aggregate moisture and the resulting free-water correction before production.

WHAT THIS TOOL DOES NOT DO

No automatic EN 206 conformity claim.

The tool deliberately leaves national/project composition limits to the user because those requirements depend on the applicable implementation, constituent system and specification.

Check the current national adoption and complementary provisions.
Use verified composition limits rather than copied lookup values.
Replace default material properties with current test data.
Confirm the mixture through the required trials, production control and acceptance process.