Which standards are related?

This topic is commonly discussed alongside EN 196-6, ASTM C204, BS 4550, AASHTO T153. Always confirm requirements with the official standard text and your quality system.

Testing & Analysis Systems

Blaine specific surface calculator

Compute cement Blaine specific surface (cm²/g and m²/kg) from device constant K, density, air-flow time, and optional porosity and temperature — aligned with EN 196-6 and ASTM C204 practice.

Inputs

Formula mode

Device constant K

Cement density ρ (g/cm³)

Air flow time t (s)

Bed porosity e

Air temperature (°C)

Results

Specific surface area (cm²/g)

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Specific surface area (m²/kg)

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Formula

Auxiliary calculation only — confirm bed preparation, calibration, and reporting with EN 196-6, ASTM C204, and your accredited procedure.

Advanced options

Specimen mass from bed volume

Optional: enter bed volume V if already known; uses ρ and e from the main inputs.

Bed volume V (cm³)

Cement mass m

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Device constant from reference cement

Invert the selected formula using certified reference S_ref and your measured t_ref.

Reference S_ref (cm²/g)

Reference ρ_ref (g/cm³)

Reference t_ref (s)

Reference e_ref

Reference air temperature (°C)

Calculated K

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Bed volume from mercury masses

V = (m₂ − m₃) / ρ_H per standard bed-volume procedure.

m₂ — empty cell mercury mass (g)

m₃ — bed mercury mass (g)

Mercury temperature (°C)

Mercury density ρ_H

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Bed volume V

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What this measures

Specific surface area (S) is the total surface of all particles in one gram of material. Blaine air permeability relates measured air-flow time t through a compacted powder bed to S, using the bed porosity e, cement density ρ, air viscosity η, and an apparatus device constant K found by calibration on reference cement.

| Unit | Meaning | |------|---------| | cm²/g | Common on Blaine reports (e.g. 48 800) | | m²/kg | SI-friendly; 1 cm²/g = 0.1 m²/kg |

Finer grinding increases surface area, lengthens flow time, and increases S.

General formula

S = (K/ρ) · (√e³ / (1−e)) · (√t / √(0.1·η))

S — cm²/g; ρ — g/cm³; e — bed porosity (0–1); t — s; η — Pa·s from air temperature (Sutherland).
K — dimensionless constant for your cell, preparation, and procedure (reference cement calibration).

Simplified shortcut

At e = 0.500 and ~20 °C (fixed η):

S = (524.2 · K / ρ) · √t

Use the General mode when porosity or lab temperature differ from standard practice.

Device constant K

K is not a universal physical constant. Invert the formula with a certified reference cement (S_ref, measured t_ref, same ρ, e, temperature) — see Advanced options on the calculator.

Bed volume and specimen mass

Before measuring t, prepare a bed at target e:

V = (m₂ − m₃) / ρ_H (cm³) from mercury masses, or enter V manually if already known.
m = (1 − e) · ρ · V (g) — at e = 0.5, half the bed volume is solid cement.

Common errors

| Issue | Effect | |-------|--------| | Assuming e = 0.5 while the bed is off-spec | Systematic bias in S | | Ignoring temperature with the simplified formula | Slight S drift | | Wrong ρ or stale K | Scaled or shifted results | | Poor compaction or cracked bed | Scattered t, repeat test |

Disclaimer

This tool supports training and cross-checks. EN 196-6, ASTM C204, and your accredited quality system define binding requirements for apparatus, bed preparation, and reporting.

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