Method of test for determination of water absorption, apparent specific gravity and porosity of natural building stones

IS 1124: Scope Summary & Key Specifications

• Scope: Method for determination of true specific gravity of natural building stones.

• Test Piece Preparation:

  • Clause 6.6: Size and shape of test pieces must be clearly indicated.
  • Clause 6.7: Detailed description of test piece preparation is mandatory.

• Key Parameters (from Clause 6.1):
  Variables A, B, C define test conditions or sample characteristics (refer to clauses 6.1 & 6.2 for exact definitions).

• Evaluation & Reporting (Table 6, Clause 6.7):
  Results must be evaluated and reported per the standard format.

Typical Formula for Specific Gravity (G):

[ G = \frac{\text{Mass in air}}{\text{Mass in air} - \text{Mass in water}} ]

• Mass measured using a balance.
• Test piece fully saturated and surface dried.

Test Piece Size & Shape (Typical Guidelines):

Contact for Reference & Testing:

• Central Laboratory: Sahibabad Industrial Area, Plot No. 20/9, Site IV
• Regional Offices: New Delhi, Kolkata, Chandigarh, Chennai, Mumbai
• Branch Offices: Ahmedabad, Bangalore, Bhopal, Bhubaneswar, Coimbatore, Faridabad, etc.

flowchart LR
    A[Test Piece Preparation] --> B[Measure Mass in Air]
    B --> C[Measure Mass in Water]
    C --> D[Calculate Specific Gravity]
    D --> E[Evaluate & Report Results]

Note: For detailed test procedure, sample conditioning, and formula constants, refer to IS 1124 clauses 6.1 to 6.7.

IS 1124: Selection of Samples - Key Points

• Clause 2.1: Samples must represent the true average quality of the stone type or grade.
• Clause 2.2: Samples are taken from quarried stone or natural rock, sized adequately to prepare the required number of test specimens.
• Clause 2.3: If stone quality varies perceptibly, multiple samples should be selected to cover the range of properties.
• Clause 6.6: The size and shape of test pieces must be clearly specified for testing.

Sample Size & Preparation (General Guidance)

Summary Diagram of Sample Selection Process

flowchart TD
    A[Quarried Stone / Natural Rock] --> B{Check Quality Variation}
    B -- No --> C[Select Representative Sample]
    B -- Yes --> D[Select Multiple Samples]
    C --> E[Prepare Test Pieces]
    D --> E
    E --> F[Conduct Tests with Specified Size & Shape]

Note: For precise test piece dimensions and number, refer to IS 1124 test methods or related standards like IS 3495.

IS 1124: Preparation of Test Pieces for True Specific Gravity of Natural Building Stones

Key Specifications & Procedures:

• Size & Shape (Clause 6.6):
  Test pieces' size and shape must be clearly indicated.

• Material Selection (Clause 3.1):
  Use crushed/broken stone passing 20 mm IS sieve but retained on 10 mm IS sieve.

• Test Piece Weight (Clause 5.1):
  Approximately 1 kg per test piece.

• Preparation Steps (Clause 5.1):

  1. Wash to remove dust particles.
  2. Immerse in distilled water at 20–30°C for 24 hours.
  3. Remove entrapped air by gentle agitation (clockwise & anti-clockwise rotation).
  4. Drain water, surface dry gently on dry cloths until no moisture is removed.
  5. Spread on second dry cloth, air dry for ≥10 minutes away from direct heat/sunlight.
  6. Weigh the surface-dried test piece (weight = B).

• Documentation (Clause 6.7):
  Include detailed description of test piece preparation in the report.

Summary Table for Preparation:

This ensures accurate determination of true specific gravity by standardizing test piece preparation.

flowchart TD
    A[Crushed Stone (10-20 mm)] --> B[Wash to Remove Dust]
    B --> C[Soak in Distilled Water (24 hrs, 20-30°C)]
    C --> D[Remove Entrapped Air (Agitation)]
    D --> E[Drain & Surface Dry on Cloths]
    E --> F[Air Dry ≥10 min (No direct heat)]
    F --> G[Weigh Test Piece (Weight B)]

IS 1124 - Apparatus Key Specifications & Formulas

Apparatus (Clause 4.2)

• Glass Vessel: ~1.5 litre capacity.
• Dry Absorbent Cloths: Two pieces, each of 0.5 m² area.
• Water Cylinder: Larger cylinder for immersion and drainage.

Sample Preparation (Clause 5.3)

• Dry sample in oven at 100-110°C for ≥ 24 hours.
• Cool in desiccator to room temperature.
• Weigh dried sample → Weight = A.
• Record room temperature during test.

Key Variables (Clause 6.1)

• A, B, C are weights/volumes related to sample and apparatus (refer IS 1124 for exact definitions).

Evaluation (Clause 6.7)

• Include detailed description of sample preparation.
• Use provided tables for specific gravity calculations.

Typical Calculation for True Specific Gravity (G):

[ G = \frac{A}{(B - C)} ]

Where:

• A = Dry weight of sample (oven-dried)
• B = Weight of sample in water
• C = Weight of water displaced (or apparatus correction)

Summary Table: Apparatus Dimensions

flowchart TD
    A[Sample Collection] --> B[Dry in Oven (100-110°C, ≥24h)]
    B --> C[Cool in Desiccator]
    C --> D[Weigh Sample (A)]
    D --> E[Immerse in Water to get B]
    E --> F[Calculate Specific Gravity G = A/(B-C)]

For detailed apparatus and procedure, refer IS 1124 full text.

IS 1124 - Procedure Key Points

1. Test Piece Preparation (6.6 & 6.7):

   • Size and shape of test pieces must be clearly indicated.
   • Include detailed description of preparation method.

2. Apparent Porosity Calculation (6.3): [ \text{Apparent Porosity} = \frac{1000 - C}{\text{selected}} \times 100 ]

   • Where C is a parameter defined in clauses 6.1 and 6.2 (usually weight or volume related).

3. Parameters A, B, C (6.1 & 6.2):

   • Values and definitions of A, B, C are provided in these clauses and are essential for calculations.

4. Evaluation & Reporting (6.7 Table):

   • Follow the tabulated format for test result evaluation and reporting as per clause 6.7.

Summary Diagram of Procedure Flow

flowchart TD
    A[Test Piece Preparation] --> B[Indicate Size & Shape]
    B --> C[Conduct Test]
    C --> D[Calculate Apparent Porosity]
    D --> E[Evaluate & Report Results]
    E --> F[Include Preparation Description]

For detailed values of A, B, C and the full evaluation table, refer directly to clauses 6.1, 6.2, and 6.7 of IS 1124.

IS 1124: Evaluation and Report of Test Results (Clause 6.7 and related)

Key Specifications for Reporting:

• Test Piece Preparation: Detailed description of how test specimens were prepared must be included.
• Size & Shape: Indicate the size and shape of test pieces (Clause 6.6).
• Drying Procedure (Clause 5.3):
  • Dry samples at 100-110°C for ≥24 hours.
  • Cool in a desiccator to room temperature.
  • Weigh the dry sample (weight = A).
  • Record room temperature during testing.

Typical Report Contents:

• Identification of test pieces (size, shape).
• Preparation method (drying, conditioning).
• Test environment conditions (temperature, humidity).
• Measured weights and volumes.
• Calculated parameters (e.g., true specific gravity).

Formula for True Specific Gravity (from Clauses 6.1, 6.2):

[ \text{True Specific Gravity (G)} = \frac{A}{A + B - C} ] Where:

• A = Oven-dried weight of specimen,
• B = Weight of specimen in water,
• C = Weight of saturated surface dry specimen in air.

Summary Table for Test Reporting:

flowchart TD
    A[Test Piece Preparation]
    B[Drying at 100-110°C for ≥24h]
    C[Cooling in Desiccator]
    D[Weigh Dry Specimen (A)]
    E[Weigh Saturated Surface Dry Specimen (C)]
    F[Weigh Specimen in Water (B)]
    G[Calculate True Specific Gravity]
    
    A --> B --> C --> D
    D --> E
    E --> F
    D --> G