Methods of Tests for Building Limes, Part 11: Determination of Setting Time of Hydrated Lime

IS 6932 Part 11: Scope & Key Specifications for Setting Time of Hydrated Lime

Scope:
This part covers the determination of the setting time of hydrated lime using the Vicat apparatus.

Key Specifications & Procedures:

• Apparatus:

  • Use Vicat apparatus with a needle (C) replaced by a needle with annular attachment (F) for final setting time (Clause 3.3).

• Final Setting Time:

  • Defined as the time when the needle makes an impression on the lime surface, but the annular attachment does not.
  • If scum forms, test the underside of the block.

• Environmental Conditions (Clause 3.1.2):

  • Temperature of lime, water, and test room: 27 ± 2°C
  • Relative humidity: ≥ 90%
  • Avoid draughts.

Summary Table:

This ensures standardized and reliable measurement of hydrated lime setting time per IS 6932 Part 11.

IS 6932 (Part 11) - 1983: Determination of Setting Time of Hydrated Lime

Key Specification (Clause 3.3 - Final Setting Time)

• Use Vicat apparatus with annular needle attachment (F) replacing standard needle (C).
• Final setting time is when:
  • The needle makes an impression on the lime surface.
  • The annular attachment fails to make an impression.
• If scum forms on the surface, test on the underside of the test block.

References & Amendments

• Vicat apparatus specification: IS 5513:1996 (updated from IS 4031-1968).
• Methods align with IS 4031 (Part 5): 1988 for initial/final setting times of hydraulic cement.
• Results rounding as per IS 2-1960.

Summary Table for Setting Time Test Apparatus

Practical Notes:

• Final setting time indicates the lime's transition from plastic to solid state.
• Use gentle application to avoid false impressions.
• Testing underside avoids surface anomalies like scum.

flowchart TD
    A[Vicat Apparatus] --> B[Needle (C)]
    A --> C[Annular Attachment (F)]
    B --> D{Impression on surface?}
    D -- Yes --> E[Check annular attachment]
    E --> F{Annular makes impression?}
    F -- No --> G[Final Setting Time reached]
    F -- Yes --> H[Not final set]
    D -- No --> H

This method ensures consistent determination of hydrated lime's final setting time as per IS 6932 (Part 11).

Apparatus as per IS 6932 Part 11

1. Vicat Apparatus (IS: 5513-1976)

• Used for determining setting times of lime.
• For final setting time, replace the standard needle (C) with a needle having an annular attachment (F).

2. Environmental Conditions for Testing (Clause 3.1.2)

• Temperature: 27 ± 2℃
• Relative Humidity: ≥ 90%
• Avoid draughts during testing.

3. Determination of Final Setting Time (Clause 3.3)

• Apply the annular needle gently on the test block surface.
• Final set when the needle makes an impression but the annular attachment does not.
• If scum forms, test the underside of the block.

Summary Table: Vicat Needle Types

flowchart LR
    A[Lime Test Block] --> B[Vicat Apparatus]
    B --> C{Needle Type}
    C -->|C| D[Initial Setting Time]
    C -->|F (Annular)| E[Final Setting Time]
    E --> F{Impression on surface?}
    F -->|Yes| G[Final set reached]
    F -->|No| H[Not set yet]

Note: Use clean appliances and maintain specified temperature and humidity for accurate results.

IS 6932 Part 11: Preparation of Test Sample for Building Limes

Key Specifications & Conditions:

• Sample Form: Putty, prepared as per Clause 3.2.4 of IS 6932 (Part 8) - 1973.
• Appliances: Must be clean for gauging.
• Temperature Control: Lime, water, and test room temperature at 27 ± 2°C.
• Humidity: At least 90% relative humidity.
• Environment: Away from drafts.

Preparation Summary:

1. Mix lime and water to form putty (refer IS 6932 Part 8 for workability method).
2. Maintain temperature and humidity conditions strictly during preparation and testing.
3. Use clean tools to avoid contamination.

Final Setting Time (Clause 3.3):

• Use Vicat apparatus with annular needle attachment.
• Final setting time is when the needle makes an impression but the annular attachment does not.
• If scum forms, test on the underside of the block.

Quick Reference Table: Vicat Apparatus Needles

flowchart TD
    A[Prepare Lime Putty] --> B[Maintain 27 ± 2°C & 90% RH]
    B --> C[Use Clean Appliances]
    C --> D[Fill Vicat Mould]
    D --> E{Test Setting Time}
    E -->|Initial| F[Needle (C)]
    E -->|Final| G[Needle with Annular (F)]
    G --> H[Final Setting Time Determined]

For detailed mixing ratios and workability, refer IS 6932 Part 8 (Clause 3.2.4).

IS 6932 Part 11: Determination of Initial Setting Time of Hydrated Lime

Key Specification (Clause 3.2)

• Prepare test block as per Clause 3.1.
• Place block under needle-bearing rod (needle C).
• Lower needle gently to touch surface, then release quickly.
• Initially, needle fully pierces block.
• Repeat until needle fails to pierce block by 5 ± 0.5 mm from mould bottom.
• Initial Setting Time = Time from water addition to needle failing to pierce by 5 ± 0.5 mm.

Summary Table for Needle Penetration

Notes:

• The test is manual; repeat measurements at intervals.
• Time recorded in minutes from mixing water with lime.
• Ensures consistency in lime setting behavior for construction use.

flowchart TD
    A[Add water to lime] --> B[Prepare test block]
    B --> C[Lower needle on block surface]
    C --> D{Needle penetration > 5 ± 0.5 mm?}
    D -- Yes --> E[Repeat test after interval]
    D -- No --> F[Record elapsed time as Initial Setting Time]

This method ensures reliable determination of hydrated lime's initial setting time per IS 6932-11.

IS 6932 Part 11: Determination of Final Setting Time of Hydrated Lime

Key Specification (Clause 3.3):

• Use Vicat apparatus with needle having annular attachment (F) replacing the standard needle (C).
• Final setting time is the time elapsed from mixing water with lime until:
  • The needle makes an impression on the test block surface,
  • While the annular attachment fails to make an impression.
• If a scum forms on the surface, test on the underside of the test block.

Summary of Procedure:

Important Notes:

• Final setting time indicates the lime has hardened sufficiently to resist penetration by the annular ring.
• This test complements initial setting time (needle penetration of 5 ± 0.5 mm).

Diagram of Vicat Needle Setup:

graph LR
A[Vicat Apparatus] --> B[Standard Needle (C)]
A --> C[Annular Attachment (F)]
B --> D[Penetrates test block surface]
C --> E[No impression on surface at final set]

This method ensures accurate determination of the final setting time critical for quality control of hydrated lime in construction.

IS 6932 Part 11 - Test Conditions Summary

Key Test Conditions (Clause 3.1.2)

• Temperature: 27 ± 2°C for lime, water, and test room.
• Relative Humidity: Minimum 90%.
• Environment: Away from draughts.
• Appliances: Must be clean for gauging.

Apparatus for Final Setting Time (Clause 3.3)

• Use Vicat apparatus with an annular attachment on the needle.
• Final Setting Time: When needle makes an impression but annular attachment does not.
• If scum forms, test underside of block.

Preparation (Clause 3.1)

• Sample in putty form as per IS 6932 Part 8 (workability determination).

Summary Table: Test Environment Parameters

flowchart TD
    A[Test Preparation] --> B[Maintain Temp 27±2°C]
    B --> C[Maintain RH ≥ 90%]
    C --> D[Use Clean Appliances]
    D --> E[Perform Test with Vicat Needle + Annular Attachment]
    E --> F{Needle impression?}
    F -- Yes, Attachment no impression --> G[Final Setting Time Recorded]
    F -- No --> H[Continue Testing]

This ensures consistent, reliable lime setting time measurements per IS 6932 Part 11.

IS 6932 (Part 11) - Reporting of Results for Setting Time of Hydrated Lime

Key Specifications for Reporting:

• Final Setting Time is determined using the Vicat apparatus with an annular needle attachment.
• The lime is considered finally set when:
  • The needle makes an impression on the test block surface,
  • While the annular attachment fails to do so.
• If a scum forms on the surface, use the underside of the test block for determination.
• Testing conditions:
  • Temperature of lime, water, and test room: 27 ± 2°C
  • Relative humidity: ≥ 90%
  • Avoid draughts during testing.
• Use clean appliances for gauging.
• Results should be rounded off as per IS 2-1960.

Summary Table for Final Setting Time Determination:

flowchart TD
    A[Test Block Preparation] --> B[Apply Needle with Annular Attachment]
    B --> C{Does Needle Make Impression?}
    C -- Yes --> D{Does Annular Attachment Make Impression?}
    D -- No --> E[Record Final Setting Time]
    D -- Yes --> F[Continue Testing]
    C -- No --> F
    F --> B

This ensures standardized and reproducible reporting of setting time results per IS 6932 (Part 11).