gypsum building plaster, Part 2: Premixed lightweight plaster

IS 2547 (Part 2) - Scope and Key Specifications

• Scope: Covers Premixed Lightweight Gypsum Building Plaster including chemical analysis and physical properties.

• Chemical Analysis:

  • Soluble Sodium Oxide (Na2O) %: [ \text{Na}_2\text{O} % = \frac{A \times V \times 100}{W \times 1000000} ] where:
    • ( A ) = ppm of Na2O in solution
    • ( W ) = mass of sample (g)
    • ( V ) = volume of solution (ml)

• Free Lime Content (Appendix B Table 1):

  • Using 5 g sample, 1 ml of 0.50 N acid corresponds to 0.37% Ca(OH)2.

• Quality Control (Clause 5.4.1):

  • Calculate average ( X ) and range ( R ) of test results.
  • Acceptable limits: [ X - 0.4R \geq \text{Minimum Specified Limit} ] [ X + 0.4R \leq \text{Maximum Specified Limit} ]

• Reference Standards:

  • Chemical analysis per IS 4032-1968.
  • Bureau of Indian Standards governs licensing and use of Standard Mark.

This standard ensures gypsum plaster meets chemical purity and strength criteria for quality construction use.

IS 2547 (Part 2) - Definitions & Key Specifications

1. Definitions (Clause 2.0):

   • The standard defines terms specifically for gypsum building plaster, ensuring uniform understanding.

2. Statistical Evaluation of Test Results (Clause 5.4.1):

   • Calculate average (X) and range (R) for compressive strength and free lime content.
   • Use expressions:
     [ X - 0.4R \geq \text{Minimum Limit} \quad \text{and} \quad X + 0.4R \leq \text{Maximum Limit} ]
   • Ensures test results fall within specified tolerance limits.

3. Chemical Analysis (Clause 1.3 and Appendix B):

   • Sodium Oxide (Na₂O) % Calculation:
     [ \text{Na}_2\text{O} % = \frac{A \times V}{W} \quad \text{where,} \quad A = \text{ppm in solution}, \quad W = \text{sample mass (g)}, \quad V = \text{volume factor} ]
   • Free Lime Determination:
     • 5 g sample reacts with 1 ml 0.50 N acid = 0.37% Ca(OH)₂.

Summary Table: Statistical Acceptance Criteria

This ensures quality control by considering variability in test results.

If you need detailed chemical analysis procedures or further definitions, refer to IS 4032 and IS 2547 Part 2 full text.

IS 2547 Part 2 — Classification & Key Specifications for Lightweight Gypsum Plaster

Classification (Clause 3)

• Lightweight plaster contains lightweight aggregates and retarded hemihydrate gypsum complying with IS 2547 Part 1.
• Types of plasters classified as:
  • Undercoat Plasters (Type A):
    • Browning Plaster
    • Metal Lathing Plaster
    • Bonding Plaster
  • Final Coat Plaster (Type B):
    • Finish Plaster

Key Specifications (Table 1, Clause 4.1)

Chemical Analysis Formula (Sodium Oxide %)

[ \text{Na}_2\text{O} % = \frac{A \times 100}{W} ]

• A: ppm of sodium oxide in solution
• W: mass of sample (g)

Notes

• Free lime determination: 5 g sample + 1 ml 0.5 N acid = 0.37% Ca(OH)₂.
• Tests per Clause 5.3.1 require homogenized samples from each package.

flowchart TD
    A[Lightweight Gypsum Plaster] --> B{Classification}
    B --> C[Undercoat Plasters (Type A)]
    B --> D[Final Coat Plaster (Type B)]
    C --> E[Browning Plaster]
    C --> F[Metal Lathing Plaster]
    C --> G[Bonding Plaster]
   

IS 2547 Part 2: Physical and Chemical Requirements for Gypsum Building Plaster

Key Specifications (Clause 4.1 & Table 1)

• The plaster must meet physical and chemical requirements as per Table 1 (not fully reproduced here).
• Tests must be performed on composite samples (Clause 5.4.2).

Important Chemical Determinations:

Summary of Chemical Calculations

Sodium Oxide (Na₂O) % = (A × 100) / W

Where:
- A = parts per million (ppm) of Na₂O in solution
- W = mass of sample in grams

Notes:

• All chemical tests must conform to IS 2547 Part 2 and related IS codes (e.g., IS 4032).
• Physical and chemical test results on composite samples must satisfy all specifications.
• For detailed test procedures and limits, refer to Table 1 in the code and relevant appendices.

flowchart TD
    A[Sample Preparation] --> B[Chemical Analysis]
    B --> C{Test Parameters}
    C -->|Na2O| D[IS 4032 Method]
    C -->|Free Lime| E[Acid Neutralization]
    C -->|MgO| F[Sample Solution Prep]
    D --> G[Calculate % Na2O]
    E --> H[Calculate

IS 2547 Part 2: Sampling and Criteria for Conformity

Key Clauses:

• 5.1.1 Sampling: Samples must be taken separately from each lot for testing.
• 5.2 Sample Size: Number of packages to sample depends on lot size, per Table 2.
• 5.4 Criteria for Conformity:
  • 5.4.1: Conditions for acceptance must be met (usually acceptance quality limits).
  • 5.4.2: All test results on composite samples must meet specification requirements.

Table 2: Number of Packages to Sample (Example format)

(Exact values per IS 2547 Part 2 Table 2)

Summary:

• Select sample packages as per lot size (Table 2).
• Test samples individually and as composite.
• Lot is conforming if all composite test results meet specs.
• Use acceptance criteria from 5.4.1 (usually AQL or similar).

flowchart TD
    A[Start: Lot Received] --> B[Select Sample Packages (Table 2)]
    B --> C[Test Samples Individually]
    C --> D{Do all individual samples conform?}
    D -- No --> E[Reject Lot]
    D -- Yes --> F[Prepare Composite Sample]
    F --> G[Test Composite Sample]
    G --> H{Composite meets specs?}
    H -- No --> E
    H -- Yes --> I[Accept Lot]

This ensures quality control via statistically valid sampling and testing per IS 2547 Part 2.

IS 2547 Part 2 (1976) — Marking and Packaging Key Points

Marking (Clause 6.1)

• Each package must clearly show:
  • Manufacturer's name
  • Type of plaster (undercoat or final coat)
  • Date of manufacture
  • Net mass
• Optional: Use of Standard Mark as per BIS Act 1986 provisions (Clause 6.1.1 & 6.2)

Packaging & Sampling (Clause 5.2 & Table 5.3)

• Samples must be taken individually from each package.
• Samples for compressive strength and free lime content tests.
• Store samples in clean, dry, airtight containers for lab testing.

Summary Diagram

flowchart TD
    A[Package] --> B[Marking]
    B --> B1[Manufacturer's Name]
    B --> B2[Type of Plaster]
    B --> B3[Date of Manufacture]
    B --> B4[Net Mass]
    B --> B5[Standard Mark (optional)]

    A --> C[Sampling]
    C --> C1[Select packages as per lot size]
    C --> C2[Take samples individually]
    C --> C3[Store in airtight containers]
    C --> C4[Test for compressive strength & free lime]

This ensures traceability, quality control, and compliance with BIS standards.

IS 2547 Part 2: Key Formulas & Specifications for Soluble MgO & Na2O

1. Determination of Soluble Magnesium Oxide (MgO)

• Based on IS 1760-1962, 200 ml sample solution is taken.
• Calcium is precipitated per Clause 9.3 of IS 1760-1962.
• Filtrate from calcium estimation is used for Mg determination.

Formula for MgO %:

[ \text{MgO %} = \frac{A \times 0.1291 \times 2.5 \times 100}{B} ]

• A = mass of oxinate (g)
• B = mass of sample (g)

2. Determination of Soluble Sodium Oxide (Na₂O)

• Follow IS 4032-1968 (Clause 4.11) with modifications:
  • Take 50 ml sample solution in 100 ml flask.
  • Add 9 ml of 63,000 ppm CaO solution.
  • Make volume up to 100 ml.

Formula for Na₂O %:

[ \text{Na}_2\text{O %} = \frac{A \times 100}{W} ]

• A = ppm of Na₂O in solution
• W = mass of sample (g)

3. Additional Notes

• For free lime (Ca(OH)₂) determination, refer Appendix B Table 1.
• 1 ml of 0.50 N acid neutralizes 0.37% Ca(OH)₂ in a 5 g sample.

flowchart LR
    A[Sample Solution] --> B[Precipitate Calcium]
    B --> C[Filtrate for MgO]
    C --> D[Measure Oxinate Mass (A)]
    D --> E[Calculate MgO % using formula]

    A --> F[Take 50 ml for Na2O]
    F --> G[Add CaO solution]
    G --> H[Make volume 100 ml]
    H --> I[Measure Na2O ppm (A)]
    I --> J[Calculate Na2O % using formula]

Summary:

• Use oxinate mass for MgO % calculation.
• Use ppm concentration

Key Formulas and Specifications for Determination of Free Lime Content (IS 2547 Part 2)

1. Statistical Evaluation (Clause 5.4.1)

For test results on free lime content:

• Calculate Average (X) and Range (R) of test values.
• Compute expressions:
  [ X \pm 0.4R ]
• Acceptance criteria:
  [ X - 0.4R \geq \text{Minimum limit} \quad \text{and} \quad X + 0.4R \leq \text{Maximum limit} ]

2. Free Lime Content Determination (Appendix B, Table 1)

• Sample size: 5 g
• Titration factor: 1 ml of 0.50 N acid corresponds to 0.37% Ca(OH)₂ (free lime)

3. Procedure Summary (from Appendix B)

• Dissolve sample and titrate with 0.50 N acid.
• Calculate free lime content using: [ \text{Free Lime (%)} = \text{ml acid used} \times 0.37 ]

4. Sampling (Clause 5.2, Table 2)

Summary Diagram: Free Lime Content Testing Flow

flowchart TD
    A[Sample Collection] --> B[Weigh 5 g Sample]
    B --> C[Titrate with 0.50 N Acid]
    C --> D[Calculate Free Lime % = ml Acid × 0.37]
    D --> E[Calculate Average (X) and Range (R)]
    E --> F[Check X ± 0.4R against Limits]
    F --> G{Accept or Reject}

Note: Ensure samples are stored in clean, dry, airtight containers before testing to avoid moisture effects.