Methods of physical tests for hydraulic cement, Part 2: Determination of fineness by specific surface by Blaine air permeability method

IS 4031 Part 2 (1999) - Scope Key Formulas & Tables

1. Scope Overview

• Covers determination of specific surface (fineness) of cement by air permeability method.
• Uses apparatus constant (K), air viscosity, mercury density, and temperature corrections.

2. Key Formula for Specific Surface (Clause 5.6.1)

[ S = S_0 \times \frac{K \cdot \rho \cdot (1 - e)}{\rho_0 \cdot (1 - e_0)} \times \frac{t}{t_0} ]

Where:

3. Table 1: Density of Mercury, Viscosity of Air & (V_{0.1}) (Clause 5.4.2)

Use linear interpolation for intermediate temperatures.

4. Table 2: Apparatus Constant (K) (Clause 5.6.4)

| Cement Type | Formula for Fineness (S) | Apparatus Constant (K) | Porosity (e) | Temp. Diff. | Notes | |----------------

IS 4031 Part 2: Key References, Formulas & Tables

1. Table 1: Physical Properties vs Temperature (Clause 5.4.2)

Intermediate values by linear interpolation.

2. Basic Formula for Specific Surface (Clause 5.6.1)

[ S = S_0 \times \frac{p}{p_0} \times \frac{(1 - e)}{(1 - e_0)} \times \frac{t_0}{t} ]

Where:

• ( S ) = Specific surface of test cement (cm²/g)
• ( S_0 ) = Specific surface of reference cement (cm²/g)
• ( p, p_0 ) = Density of test and reference cement (g/cm³)
• ( e, e_0 ) = Porosity of test and reference cement bed
• ( t, t_0 ) = Time for test and reference cement
• Air viscosity correction factors ( n, n_0 ) from Table 1 apply if temperature varies.

3. Apparatus Constant (K) Formulas (Clause 5.6.4, Table 2)

| Cement Type | Formula for Fineness ( S ) | Apparatus Constant ( K ) | Porosity ( e_0 ) | Temp. Difference Allowed | Notes | |---------------------|-----------------------------------------------|---------------------------------|

IS 4031 Part 2: Sampling and Selection of Test Specimen

Key Points:

• Sampling Method:
  Cement samples must be taken as per the prescribed procedure to ensure representativeness. Sampling should avoid contamination and moisture exposure.

• Test Specimen Selection:
  Specimens are selected from the homogenized sample ensuring uniformity. The sample size must be adequate for all required tests.

Apparatus Constant (K) Calculation (Clause 5.6.4, Table 2):

• S₀ = Fineness of calibrated sample
• V, N, T, ρ, V₀, t = Parameters related to volume, time, temperature, density, etc.

Reporting:

• Round off results as per IS 2:1960 rules.

Summary Diagram:

flowchart LR
    A[Sampling of Cement] --> B[Homogenization]
    B --> C[Selection of Test Specimen]
    C --> D[Calculate Apparatus Constant (K)]
    D --> E[Perform Test]
    E --> F[Report Results (IS 2:1960 rounding)]
``

IS 4031 Part 2: Apparatus and Materials - Key Data

1. Table: Density of Mercury, Viscosity of Air & VO.In vs Temperature (°C)

Intermediate values: Use linear interpolation.

2. Apparatus Constant (K) Formulae for Fineness S (Table 2, Clause 5.6.4)

IS 4031 Part 2: Key Formulas & Tables for Test Procedure

1. Basic Formula for Specific Surface (Clause 5.6.1)

[ S = S_0 \times \frac{P_0}{P} \times \frac{(1 - e)}{(1 - e_0)} \times \frac{t}{t_0} ]

Where:

• ( S ) = specific surface of cement under test (cm²/g)
• ( S_0 ) = specific surface of reference cement (cm²/g)
• ( P, P_0 ) = densities of test and reference cement (g/cm³)
• ( e, e_0 ) = porosity of test and reference cement beds
• ( t, t_0 ) = flow times of test and reference cements (seconds)

2. Apparatus Constant (K) Calculation (Clause 5.6.4, Table 2)

3. Table 1: Density of Mercury & Viscosity of Air at Various Temperatures (Clause 5.4.2)

| Temperature (°C) | Mercury Density (g/cm³) | Air Viscosity (Pa.s) | (V_{0.In}) | |------------------|

IS 4031 Part 2: Test Conditions Summary

1. Test Environment (Clause 5.1)

• Temperature: 27 ± 2°C (or optionally 20 ± 2°C if purchaser agrees)
• Relative Humidity: ≤ 65%
• All materials must be at lab temperature and protected from moisture absorption.

2. Key Table: Air Properties vs Temperature (Clause 5.4.2, Table 1)

Use linear interpolation for intermediate values.

3. Specific Surface Calculation (Clause 5.6.1)

[ S = S_0 \times \frac{p_0}{p} \times \frac{(1 - e_0)}{(1 - e)} \times \frac{t_0}{t} \times \frac{n}{n_0} ]

Where:

• (S) = specific surface of test cement (cm²/g)
• (S_0) = specific surface of reference cement (cm²/g)
• (p, p_0) = densities of test and reference cement (g/cm³)
• (e, e_0) = porosities of test and reference cement beds
• (t, t_0) = flow times for test and reference cement (seconds)
• (n, n_0) = air viscosities at test and reference temperatures (Pa.s)

4. Apparatus Constant K (Clause 5.6.4, Table 2)

| Cement Type

IS 4031 Part 2 — Compacted Cement Bed Key Formulas & Specifications

1. Porosity and Mass of Cement Bed

• Porosity, ( e = 0.500 ) (fraction of air volume in bed)
• Volume fraction of cement = ( (1 - e) )
• Cement density = ( p ) (g/cm³)
• Bed volume = ( V ) (cm³)

Mass of cement for porosity 0.5:

[ m_1 = 0.500 \times p \times V \quad \text{(g)} \tag{1} ]

This mass ( m_1 ), when compacted as per procedure, yields a bed with porosity 0.5.

2. Mass of Cement for Any Porosity ( e ):

[ m = p \times V \times (1 - e) \quad \text{(g)} ]

3. Determination of Bed Volume ( V ) Using Mercury

• Weigh mercury filling empty cell: ( m_2 )
• Weigh mercury filling cell with cement bed: ( m_3 )
• Density of mercury at test temperature: ( D ) (from Table 1)

Bed volume:

[ V = \frac{m_2 - m_3}{D} \quad \text{(cm}^3\text{)} ]

Repeat until two ( V ) values differ by < 0.005 cm³; take mean as final volume.

4. Compaction Procedure Highlights

• Use perforated disc + filter paper discs.
• Tap cell to level cement.
• Insert plunger, press gently until cap contacts cell.
• Withdraw plunger 5 mm, rotate 90°, press again.
• Avoid rapid/vigorous pressing to maintain particle size distribution.

5. Safety Note

• Handle mercury with care; avoid skin/eye contact.

flowchart TD
    A[Calculate Cement Mass, m1 = 0.5 p V] --> B[Place Perforated Disc + Filter Paper]
    B --> C[Add Cement, Tap to Level]
    C --> D[Place Filter Paper + Insert Plunger]
    D --> E[Press Gently, Rotate, Press Again]

IS 4031 Part 2: Air Permeability Test Key Points

1. Test Conditions (Clause 5.1)

• Temperature: 27 ± 2°C (or 20 ± 2°C if purchaser desires)
• Relative Humidity: ≤ 65%
• Materials must be at lab temperature and protected from moisture.

2. Apparatus (Clause 4.1)

• Use Variable Flow Type Air Permeability Apparatus (Blaine Type) as per IS 5516.

3. Test Procedure & Formula (Clause 5.2.2 & 5.3)

Prepare a compacted cement bed from reference cement with known specific surface (So).

• Measure permeability times (t) and temperature for 3 samples, each tested thrice.
• Calculate mean time ( t_0 ) and mean temperature for each sample.

4. Key Formula

[ K = S_0 \cdot P_0 \cdot (1 - e) \cdot \frac{V^{0.1}}{n_0 \cdot V_e^3 \cdot t_0} ]

Where:

5. Additional Notes

• Air viscosity ( n_0 ) varies with temperature; refer to Table 1 in IS 4031 Part 2.
• Porosity ( e ) is fixed at 0.500 for calculations.
• Repeatability: Perform test on 3 samples, each

IS 4031 Part 2: Calibration of Apparatus (Clause 5.4 & 5.6.4)

1. Key Parameters from Table 5.3.1 (for Temperature-dependent properties)

Note: Use linear interpolation for intermediate temperatures.

2. Determination of Apparatus Constant (K)

From Table 5.6.3, depending on cement type and porosity:

• ( V ) = volume of air
• ( t ) = time
• ( e ) = porosity

Determination of Apparatus Constant (K) - IS 4031 Part 2

Key Points from Clause 5.4.2 & Table 2 (Clause 5.6.4):

• Apparatus constant K is essential for calculating fineness (S) of cement.
• It depends on:
  • Type of cement (OPC or others)
  • Porosity (e.g., 0.5 for calibrated sample)
  • Temperature difference (should be within ±3°C ideally)
  • Density and volume parameters

Important Formulas for Apparatus Constant K (from Table 2):

• ( S_0 ) = Standard fineness of calibrated sample
• ( V, V_t, V_e, V_0 ) = Volumes of various components in apparatus
• ( e ) = Porosity
• ( p ) = Density
• ( I_n ) = Instrument reading
• ( t ) = Time

Procedure:

• Calculate K using above formulae for

IS 4031 Part 2 — Calculation & Simplification (Clause 5.6)

1. Basic Formula for Specific Surface (S) — Clause 5.6.1

[ S = S_0 \times \frac{p_0}{p} \times \frac{(1 - e)}{(1 - e_0)} \times \frac{t}{t_0} \times \frac{\eta_0}{\eta} ]

Where:

• (S) = Specific surface of test cement (cm²/g)
• (S_0) = Specific surface of reference cement (cm²/g)
• (p, p_0) = Density of test and reference cement (g/cm³)
• (e, e_0) = Porosity of test and reference cement bed
• (t, t_0) = Time for test and reference cement (seconds)
• (\eta, \eta_0) = Air viscosity at test and reference temperature (Pa.s)

2. Simplification by Eliminating Density (Clause 3.15)

• Density (p) often taken as 3.15 g/cm³ for Portland cement, causing up to 1% error.
• Simplifies calculations by assuming constant density.

3. Apparatus Constant (K) — Table 2 (Clause 5.6.4)

IS 4031 Part 2 — Expression of Results (Clause 5.7 & related)

1. Basic Formula for Specific Surface (Clause 5.6.1)

[ S = S_0 \times \frac{p}{p_0} \times \frac{(1 - e_0)}{(1 - e)} \times \frac{t}{t_0} \times \frac{\eta_0}{\eta} ]

Where:

• (S) = specific surface of cement under test (cm²/g)
• (S_0) = specific surface of reference cement (cm²/g)
• (p, p_0) = densities of test and reference cement (g/cm³)
• (e, e_0) = porosities of test and reference cement beds
• (t, t_0) = time for test and reference cement (s)
• (\eta, \eta_0) = air viscosities at test and reference temperatures (Pa·s) from Table 1

2. Apparatus Constant (K) (Clause 5.6.4 & Table 2)

IS 4031 Part 2: Recalibration and Maintenance Key Points

1. Recalibration (Clause 5.4.3)

• Apparatus constant and cement bed volume change due to wear.
• Use a secondary reference cement with known specific surface for recalibration.
• Recalibrate:
  • After 1000 tests.
  • When changing:
    • Manometer fluid type.
    • Filter paper type.
    • Manometer tube.
  • If systematic deviations in reference cement readings occur.

2. Apparatus Constant Determination (Clause 5.4.2)

• Use Table 1 for properties at test temperature:

• Interpolate linearly for intermediate temperatures.

3. Maintenance Tips

• Regularly check manometer fluid level and clarity.
• Inspect filter paper and replace if contaminated.
• Confirm manometer tube integrity to avoid leaks or blockages.

Summary Diagram of Recalibration Triggers

flowchart TD
    A[Start: Apparatus in Use] --> B{Number of Tests ≥ 1000?}
    B -- Yes --> C[Recalibrate with Reference Cement]
    B -- No --> D{Changed Manometer Fluid / Filter Paper / Tube?}
    D -- Yes --> C
    D -- No --> E{Systematic Deviation in Reference Cement?}
    E -- Yes --> C

IS 4031 Part 2: Committee Composition & Key Specifications

Committee Composition (Annex A)

• Chairman: Dr. H. C. Visvesvarya, Bangalore
• Members: Representatives from:
  • Cement industries (Orissa Cement Ltd, The India Cements Ltd)
  • Engineering firms (B. G. Shirke & Co, Larsen & Toubro)
  • Research institutions (CSIR Structural Engineering Research Centre, Central Building Research Institute)
  • Government departments (CPWD, Central Water Commission, Ministry of Transport)
  • Testing & standards organizations (National Test House, Research Designs & Standards Organization)
  • Others including Geological Survey of India, Builder's Association of India

This diverse committee ensures comprehensive expertise in cement testing and standards.

Key Formulas & Tables for Fineness & Apparatus Constant (Clause 5.6.4)

• ( S_0 ): Specific surface of calibrated sample (cm²/g)
• ( e ): Porosity of powder bed (usually 0.5)
• ( V, I, N, T, p, V_0 ): Variables related to apparatus and sample volume/time

Important Notes:

• Por