Method of test for determination of weathering of natural building stones

IS 1125 - Scope & Key Specifications

• Scope: Covers testing of natural stones for properties like water absorption and volume changes after cyclic tests.

• Apparatus (Clause 4.1):

  • Enclosed balance, 1 kg capacity, sensitivity 0.01 g.
  • Suspension wire: brass, 0.81 mm dia.
  • Components: Beam (A), Loop (B), Suspension wire (C), Water level (D).

• Test Specimen Info to Report (Clause 7.2):

  • Preparation method.
  • Size & shape.
  • Sample ID: quarry location, stone name/position, date, trade name/grade.

• Key Formula (Clause 5.3):

[ \text{Water Absorption} = \frac{W_a - W_d}{W_d} \times 100% ]

Where:

• (W_a) = final weight in air after 30 cycles + 24h immersion

• (W_d) = dry weight before test

• (W_s) = weight suspended in water after test (used for volume calculation)

• Volume after test:

[ V_2 = \frac{W_a - W_s}{\rho_w} ]

(\rho_w) = density of water (usually 1 g/cm³)

Diagram of Apparatus (simplified):

graph LR
A[Beam of Balance] --> B[Loop for attachment]
B --> C[Suspension wire (0.81 mm brass)]
C --> Specimen[Specimen suspended in water]
Specimen --> D[Water level]

Note: Follow IS 2-1960 for rounding off values in reports.

IS 1125: Selection of Sample for Testing Weathering of Natural Building Stones

Key Points from Clauses 2.1 to 2.3:

• Representative Sample:
  The sample must represent the true average quality of the stone type or grade (Clause 2.1).

• Source of Sample:
  Samples can be taken from:

  • Quarried stone
  • Natural rock (as per 2.2.1 and 2.2.2)
  • Must be adequate in size to prepare the required number of test specimens (Clause 2.2).

• Multiple Samples for Variability:
  If quality varies perceptibly, select multiple samples to capture the range of properties (Clause 2.3).

Practical Guidelines:

Summary Diagram:

flowchart TD
    A[Start: Identify Stone Grade] --> B{Is stone quality uniform?}
    B -- Yes --> C[Select representative sample]
    B -- No --> D[Select multiple samples]
    C --> E[Ensure adequate size for tests]
    D --> E
    E --> F[Prepare test specimens]

Note: Always follow IS 1125 for detailed sampling and testing procedures to ensure reliable weathering assessment.

IS 1125: Preparation of Test Pieces - Key Points

• Test Piece Dimensions (Clause 3.1):

  • Cylinders: Diameter = 50 mm, Height = 50 mm
  • Cubes: Edge length = 50 mm

• Number of Test Pieces (Clause 3.3):

  • Minimum 3 test pieces per test to ensure reliability.

• Reporting Requirements (Clause 7.2):

  • Description of preparation method.
  • Size and shape of test pieces.
  • Sample identification: quarry name/location, rock position, sampling date, trade name/grade.

• Rounding Off Results (IS 2-1960):

  • Final test values should be rounded as per IS 2 guidelines.

Summary Table for Test Pieces

flowchart LR
    A[Sample Collection] --> B[Preparation of Test Pieces]
    B --> C{Shape}
    C -->|Cylinder| D[Diameter=50mm, Height=50mm]
    C -->|Cube| E[Edge=50mm]
    D & E --> F[Minimum 3 Pieces]
    F --> G[Testing]
    G --> H[Report Results]
    H --> I[Include preparation, size, ID]

This ensures standardized test piece preparation for consistent strength and durability testing of natural rock.

IS 1125 - Apparatus for Weathering Test: Key Details

Apparatus Description (Clause 4.1 & 1.83)

• Balance: Enclosed, 1 kg capacity, sensitivity 0.01 g.
• Suspension wire: Brass, diameter 0.81 mm.
• Basket: Made of 1.83 mm dia brass wire, all joints soldered.
• Key Components:
  • A: Beam of balance
  • B: Loop for attachment
  • C: Suspension wire
  • D: Water level
  • E: Bail of basket
  • 7: Suspension basket
  • K: Water jar support
  • M: Bottom of basket
  • N: Balance pan suspension rod
  • P: Cut-away section of basket

Important Weights and Volumes (Clause 5.1)

Key Formula for Absorption (A2)

[ A_2 = \frac{W_3 - W_1}{W_1} \times 100 ]

Notes

• Weights must be measured with the specified sensitive balance.
• Volume (V_1) is typically calculated from the water displacement method.
• Density (d) depends on temperature; refer to IS 2-1960 for rounding off rules.

flowchart LR
    W1[Oven-dried weight (W1)]
    W3[Surface-dried weight (W3)]
    W2[Weight in water (W2)]
    V1[Volume (V1)]
    d[Density of water (d)]
    A2[Absorption % (A2)]

    W1 --> A2
    W3 --> A2
    W2 --> V1
    V1 --> A2
    d --> A2

This apparatus and formula ensure precise measurement of specimen absorption and volume changes during weather

IS 1125: Procedure Summary for Testing

Apparatus (Clause 4.1)

• Enclosed balance, 1 kg capacity, sensitive to 0.01 g.
• Accessories for weighing specimen in water.
• Components:
  • A: Beam of balance
  • B: Loop for attachment
  • C: Suspension wire (0.81 mm dia brass)
  • D: Water level

Testing Cycles (Clause 5.2)

• Specimen placed in a 9 cm diameter, 1.5 cm deep dish.
• Add 2 g powdered gypsum + 25 ml water.
• Oven dry at 105 ± 2°C for at least 5 hours until dry.
• Cool to 25 ± 5°C.
• Repeat cycle 30 times, adding only 25 ml water after first cycle.

Key Measurements (Clause 5.3)

• ( W_A ) = Final weight in air after 30 cycles + 24h immersion.
• ( W_s ) = Final weight suspended in water after 30 cycles + 24h immersion.
• ( V_2 ) = Final volume after 30 cycles.

Rounding Off (Clause 0.3)

• Follow IS 2-1960 for rounding test results.

Formula for Specific Gravity or Volume Calculation:

[ \text{Volume } V_2 = \frac{W_A - W_s}{\rho_w} ]

where (\rho_w) = density of water (usually 1 g/cm³).

flowchart LR
    A[Start] --> B[Place specimen in dish]
    B --> C[Add 2g gypsum + 25 ml water]
    C --> D[Oven dry at 105±2°C for 5 hrs]
    D --> E[Cool to 25±5°C]
    E --> F{Repeat 30 cycles}
    F -->|Yes| C
    F -->|No| G[Weigh specimen in air (W_A)]
    G --> H[Weigh specimen suspended in water (W_s)]
    H --> I[Calculate volume (V_2)]
    I --> J[Report results]

This concise procedure ensures consistent testing and reporting under IS 1125.

IS 1125: Key Formulas & Specifications for Calculation

The code focuses on determining water absorption and volume changes of specimens after immersion and cyclic testing.

Key Parameters:

Important Formulas:

• Volume of specimen:

[ V = \frac{W_3 - W_2}{d} ]

• Water absorption (%) after 30 cycles:

[ A_2 = \frac{W_A - W_1}{W_1} \times 100 ]

• Density of specimen:

[ \rho = \frac{W_1}{V} ]

Apparatus:

• Enclosed balance (capacity 1 kg, sensitivity 0.01 g)
• Suspension wire (0.81 mm brass)
• Water container with level control

Reporting:

• Follow rounding rules per IS 2-1960.
• Report weights, volumes, absorption percentages clearly.

flowchart LR
    W1[Oven-dried weight (W1)]
    W3[Surface-dried weight (W3)]
    W2[Weight suspended in water (W2)]
    d[Density of water (d)]
    V1[Volume after 24h immersion (V1)]
    A2[Water absorption (%)]

    W3 -->|Subtract| W2
    W2 -->|Divide by| d
    d --> V1
    W1 -->|Calculate absorption with WA| A2

This concise summary aids in calculating specimen volume, density, and water absorption per IS 1125.

IS 1125: Report of Test Results - Key Points

Important Definitions (Clause 5.3)

• WA = Final weight in air of surface-dried specimen after 30 cycles + 24h immersion.
• V2 = Final volume of specimen after 30 cycles.
• Ws = Final weight of specimen suspended in water after 30 cycles + 24h immersion.

Reporting Requirements (Clause 7)

• 7.1: Report the average of three test results as:

  • % Increase in absorption
  • % Increase in volume

• 7.2: Include additional info:

  • Preparation method of test pieces
  • Size & shape of test pieces
  • Sample identification: quarry name/location, rock position, sampling date, trade name/grade

• Rounding: Final values rounded per IS 2-1960.

Typical Calculation Formulas

[ \text{Percentage Increase in Absorption} = \frac{W_A - W_0}{W_0} \times 100 ]

[ \text{Percentage Increase in Volume} = \frac{V_2 - V_0}{V_0} \times 100 ]

Where:

• (W_0), (V_0) = Initial weight and volume before test cycles.

Summary Diagram

flowchart TD
    A[Initial Specimen] --> B{Test Cycles (30 cycles + 24h immersion)}
    B --> C[Measure WA (weight in air)]
    B --> D[Measure Ws (weight in water)]
    B --> E[Measure V2 (volume)]
    C --> F[Calculate % Increase in Absorption]
    E --> G[Calculate % Increase in Volume]
    F & G --> H[Report Average of 3 Specimens + Sample Details]

Ensure all values are averaged over three specimens and reported with proper sample identification and preparation details.