Method of test for building limes, Part VIII: Determination of workability

IS 6932 Part 8: Scope - Key Specifications & Formulas

Scope Summary:

• Defines the Standard Flow Table apparatus and procedure to assess workability of materials.
• Applicable for materials adjusted to standard consistency.

Standard Flow Table Details (Clause 3.1.1.1)

Workability Evaluation (Clause 3.5)

• Procedure:
  1. Adjust material to standard consistency (spread after 1 bump = 110 mm).
  2. Note number of bumps to reach average spread of 190 mm.
• Workability is estimated based on the number of bumps required.

Important Notes

• Shaft and shoulder must be clean and oiled (Clause 3.4.1).
• Material cone applied centrally; no material should remain inside the mould after removal.
• Results rounding as per IS 2:1960.

flowchart LR
    A[Prepare Material Cone] --> B[Place on Table Center]
    B --> C[Withdraw Mould]
    C --> D[Allow Table to Fall 12.5 mm]
    D --> E[Measure Spread Diameter]
    E --> F{Spread after 1 bump = 110 mm?}
    F -- Yes --> G[Count bumps to reach 190 mm spread]
    F -- No --> H[Adjust Consistency and Repeat]

This scope defines the apparatus and method for assessing workability via flow spread on a standardized flow table.

IS 6932 Part 8 - Key Specifications & Tables for Standard Flow Table

Standard Flow Table (Clause 3.1.1.1)

• Table Top: Mild steel, polished, 30 cm diameter, 3 mm thick.
• Cast Iron Rim: Cross-section 25 mm square, external diameter 300 mm, fixed with 6 rivets.
• Engraved Circles: Diameters 70 mm, 110 mm, 190 mm, concentric, filled with wax.
• Fall Length: Exactly 12.5 mm (metal-to-metal contact).
• Mass:
  • Moving part (table top + rim + shaft): approx. 7 kg.
  • Body with cam shaft and handle: approx. 19 kg.

Workability Evaluation (Clause 3.5)

• Workability is estimated by the number of bumps required to reach a spread diameter of 190 mm.
• Initial consistency adjustment is done by achieving a spread of 110 mm after one bump.

Reporting

• Results must be rounded off as per IS:2-1960.

Summary Table: Flow Table Dimensions & Mass

If you need a diagram or further procedural details, please ask!

IS 6932 Part 8: Apparatus Specifications

• Standard Flow Table:

  • Table top diameter: 300 mm (30 cm)
  • Thickness: 3 mm, mild steel, ground and polished
  • Mounted on vertical shaft with cam mechanism
  • Fall height: 12.5 mm (metal-to-metal contact)
  • Loading rim: cast iron, 25 mm square cross-section, 300 mm external diameter
  • Six rivets symmetrically fixed under rim
  • Total mass of moving parts: approx. 7 kg
  • Total mass of body (cam shaft, handle, etc.): approx. 19 kg
  • Three concentric engraved circles on table surface with diameters:
    • 70 mm, 110 mm, 190 mm
  • Engraved lines filled with wax, polished flush

• Truncated Conical Metallic Mould:

  • Used to form the test material cone on the flow table (dimensions per Fig. 1, not fully detailed here)
  • Mould must release material cleanly without residue after removal

• Preparation and Use:

  • Shaft and shoulder cleaned and oiled with thin mineral oil before testing
  • Material cone placed centrally on table, mould withdrawn carefully
  • Test invalid if material sticks inside mould

Summary Table of Key Dimensions

flowchart TB
    A[Standard Flow Table] --> B[Table Top (300 mm dia, 3 mm thick)]
    A --> C[Cast Iron Rim (25 mm sq, 300 mm dia)]
    A --> D[Vertical Shaft with Cam]
    D --> E[Fall Height 12.5 mm]
    B --> F[Engraved Circles: 70, 110, 190 mm]
   

IS 6932 Part 8 – Preparation of Sample (Clause 3.2 & related)

• Sample Preparation:
  Follow IS 712:1973 Clause 7.2 for detailed sample preparation steps. Typically, this involves obtaining a representative portion, mixing thoroughly, and molding the sample to the required shape and size.

• Flow Table Preparation (Clause 3.4.1):

  • Clean and oil the shaft and shoulder of the standard flow table with thin mineral oil.
  • Ensure the top surface is clean and dry.
  • Place the prepared cone of material (as per Clause 3.2.3) at the center using the mould.
  • Withdraw the mould carefully; no significant material should stick inside the mould.
  • If material adheres substantially, the test is invalid and must be repeated.

• Rounding Off Results (Clause 0.3):
  Use rounding rules as per IS 2:1960 for final values.

Key Points Summary

flowchart TD
    A[Obtain Sample] --> B[Mix Thoroughly (IS 712:7.2)]
    B --> C[Shape Sample Cone]
    C --> D[Clean & Oil Flow Table Shaft]
    D --> E[Place Sample Cone on Table]
    E --> F[Withdraw Mould Carefully]
    F --> G{Material Sticks?}
    G -- Yes --> H[Repeat Test]
    G -- No --> I[Proceed with Test]

This ensures accurate and repeatable testing according to IS 6932 Part 8.

IS 6932 Part 8: Test Environment and Conditions

Key Specifications & Formulas

• Testing Temperature (Clause 3.3):
  Maintain 27 ± 2℃ for the material, flow table, and surroundings.

• Flow Table Details (Clause 3.1.1.1):

  • Table top: Mild steel, 30 cm diameter, 3 mm thick
  • Mounted on vertical shaft with 12.5 mm free fall by cam
  • Cast iron rim: 25 mm square cross-section, 300 mm external diameter
  • Engraved concentric circles: 70 mm, 110 mm, 190 mm diameters
  • Total moving mass: approx. 7 kg
  • Body mass (with cam): approx. 19 kg

• Preparation & Procedure (Clause 3.4.1):

  • Clean and oil shaft with thin mineral oil
  • Table top must be clean and dry
  • Cone of material applied centrally; no residue inside mould allowed

• Rounding Off (Clause 0.3):
  Follow IS : 2-1960 for rounding test results.

Summary Table

flowchart LR
    A[Material at 27 ± 2℃] --> B[Apply cone on flow table]
    B --> C[Withdraw mould carefully]
    C --> D[Allow table to fall freely 12.5 mm]
    D --> E[Measure flow spread on circles (70,110,190 mm)]

This ensures consistent test conditions and valid flow measurements per IS 6932 Part 8.

IS 6932 Part 8 covers the method of test for determination of workability of building limes, but does not provide detailed formulas or tables explicitly.

Key points on Workability Determination (from standard practice):

• Workability refers to the ease with which lime mortar or paste can be mixed, placed, and finished without segregation or excessive water.
• Typically assessed by consistency tests such as flow table or penetration tests.

Common Procedure (General Engineering Practice):

1. Prepare lime paste/mortar with standard water content.
2. Measure flow/spread using a flow table:
   • Place a specified volume of paste on the flow table.
   • Raise and drop the table 25 times in 15 seconds.
   • Measure the diameter of spread.
3. Penetration test:
   • Use a standard cone or needle to measure penetration depth under a fixed load/time.
4. Workability criteria:
   • Spread diameter or penetration depth within specified limits indicates acceptable workability.

Typical formula for water content adjustment:

[ \text{Water Content} = \frac{\text{Weight of Water}}{\text{Weight of Lime}} \times 100% ]

Summary Table (Example):

Note: Refer to IS 712 or related lime mortar standards for detailed test setups.

flowchart LR
    A[Prepare Lime Paste] --> B[Place on Flow Table]
    B --> C[Raise & Drop Table 25 times]
    C --> D[Measure Spread Diameter]
    D --> E{Diameter within limits?}
    E -- Yes --> F[Workability Acceptable]
    E -- No --> G[Adjust Water Content & Repeat]

In brief: IS 6932 Part 8 defines the method framework but relies on standard test methods (flow table, penetration) to quantify workability of building limes.

IS 6932 Part 8: Evaluation and Reporting of Results

Key Specifications for Evaluation (Clause 3.5)

• Workability Estimation:
  • Number of bumps to reach average spread of 190 mm.
  • Initial spread after one bump should be 110 mm.
• Material must be at standard consistency (Clause 3.2.4).

Standard Flow Table Details (Clause 3.1.1.1)

Reporting

• Round off final values as per IS 2-1960.
• Report:
  • Number of bumps to reach 190 mm spread.
  • Spread after one bump (should be ~110 mm).
  • Consistency adjustment details.

Summary Flow Table Diagram

flowchart TD
    A[Material Cone] --> B[Placed at center of Flow Table]
    B --> C[Table raised 12.5 mm]
    C --> D[Table falls freely]
    D --> E[Material spreads]
    E --> F[Measure spread diameter]
    F --> G{Spread diameter}
    G -->|110 mm| H[After 1 bump]
    G -->|190 mm| I[Final spread]

This procedure ensures consistent evaluation of material workability per IS 6932 Part 8.

Precautions and Validity of Test (IS 6932 Part 8)

• Temperature Control (Clause 3.3): Maintain material, flow table, and surroundings at 27 ± 2°C during testing to ensure consistency.

• Flow Table Preparation (Clause 3.4.1):

  • Clean and oil shaft with thin mineral oil.
  • Keep table top clean and dry.
  • Apply material cone centrally using mould; no substantial material should remain inside mould after removal.
  • If material sticks inside mould, invalidate and repeat test.

• Flow Table Specifications (Clause 3.1.1.1):

  • Table top: 30 cm diameter, 3 mm thick mild steel, polished surface.
  • Raised and dropped freely by cam: 12.5 mm fall.
  • Cast iron rim: 25 mm square cross-section, 300 mm external diameter, fixed with 6 rivets.
  • Engraved concentric circles: 70 mm, 110 mm, 190 mm diameters filled with wax.
  • Moving part mass: approx. 7 kg; total body mass approx. 19 kg.

• Rounding Off Results: Follow IS 2-1960 for rounding final values.

Summary Table

flowchart LR
    A[Prepare Material Cone] --> B[Apply Cone at Center of Table]
    B --> C{Material Sticks in Mould?}
    C -- Yes --> D[Invalidate Test & Repeat]
    C -- No --> E[Perform Test at 27±2°C]
    E --> F[Record Results]
    F --> G[Round Off as per IS 2-1960]

This

IS 6932 Part 8 - Related Standards and Specifications Summary

• Rounding Off Values:
  As per IS 2-1960, final test or analysis results must be rounded off according to the rules specified in this standard.

• Standard Flow Table (Clause 3.1.1.1):

  • Table Top: Mild steel, 30 cm diameter, 3 mm thick, ground and polished.
  • Mounting: On a vertical shaft with a free fall of exactly 12.5 mm controlled by a cam.
  • Rim: Cast iron, 25 mm square cross-section, 300 mm external diameter, fixed with 6 rivets.
  • Engraved Circles: Diameters of 70 mm, 110 mm, and 190 mm, filled with wax flush with the surface.
  • Mass: Moving part approx. 7 kg; body with cam approx. 19 kg.

• Reaffirmation: Standard reaffirmed in 2000, originally published in 1973.

Key Dimensions Table

flowchart TB
    A[Vertical Shaft] --> B[Table Top (30 cm dia, 3 mm thick)]
    B --> C[Cast Iron Rim (25 mm sq, 300 mm dia)]
    B --> D[Engraved Circles: 70, 110, 190 mm]
    A --> E[Cam Mechanism for 12.5 mm free fall]
    subgraph Masses
      F[Moving Part ~7 kg]
      G[Body with Cam ~19 kg]
    end

This setup ensures standardized flow measurement for testing materials as per IS 6932 Part 8.