calcium silicate bricks

IS 4139: Scope - Key Points & Formulas

Scope:
IS 4139 covers methods for testing and evaluating drying shrinkage of bricks.

Key Specifications:

• Measuring Apparatus (Clause 2.1):

  • Use a micrometer or dial gauge accurate to 0.002 mm.
  • Gauge mounted on a frame with 5 mm diameter steel balls or Invar steel rods as reference points.

• Rounding Off (General):

  • Results rounded as per IS 2:1960, maintaining the same significant figures as specified values.

Drying Shrinkage Calculation (Clause 5.1):

[ \text{Drying Shrinkage (%)} = \frac{\text{Wet Length} - \text{Dry Length}}{\text{Wet Length}} \times 100 ]

• Average the shrinkage of 3 bricks to represent the batch.

Summary Table: Drying Shrinkage Calculation

flowchart TD
    A[Specimen Preparation] --> B[Measure Wet Length]
    B --> C[Dry Specimen]
    C --> D[Measure Dry Length]
    D --> E[Calculate Shrinkage %]
    E --> F[Average of 3 Specimens]

Note: Always refer to the latest edition of IS 4139 and IS 2 for precise compliance and rounding rules.

IS 4139 Referenced Standards & Specifications Summary

• Rounding off values: Follow IS 2:1960 for rounding numerical results, retaining significant figures as per specified values.

• Referenced Indian Standards (Clause 2.1):

  IS Number	Year	Subject
  IS 3495 (Parts 1-4)	1992	Tests on burnt clay bricks: compressive strength, water absorption, efflorescence, warpage
  IS 5454	1978	Sampling methods for burnt clay bricks
  IS 15648	2006	Pulverized fuel ash for lime-pozzolana mixtures

• Pulverized Fuel Ash Usage: Limited quantities conforming to IS 15648 may be added to mixes (Clause 4.1).

• Drying Shrinkage Calculation (Clause 5.1):
  [ \text{Drying Shrinkage %} = \frac{\text{Wet Length} - \text{Dry Length}}{\text{Wet Length}} \times 100 ]
  Average of three specimens is taken as batch value.

• Standard Mark: Products conforming to IS 4139 carry the BIS mark, ensuring quality and compliance.

Key Takeaway

• Use IS 2:1960 for rounding.
• Refer to IS 3495 for brick testing methods.
• Use IS 15648 for pulverized fuel ash specifications.
• Calculate drying shrinkage as % difference between wet and dry lengths.

flowchart LR
    A[IS 4139 Standard] --> B[Testing Methods: IS 3495]
    A --> C[Sampling: IS 5454]
    A --> D[Pozzolana Ash: IS 15648]
    B --> E[Compressive Strength, Water Absorption, Efflorescence, Warpage]
    D --> F[Limited use in mix]

For detailed test procedures and values, consult the respective IS codes.

IS 4139 - General Quality: Key Formulas and Specifications

1. Drying Shrinkage Calculation (Clause 5.1 & Table A-5.1)

• Formula:

[ \text{Drying Shrinkage (%)} = \frac{\text{Wet Length} - \text{Dry Length}}{\text{Wet Length}} \times 100 ]

• Average drying shrinkage is the mean of 3 specimens.

2. Drying Shrinkage Limits (Clause 7.2, Table 1)

• Note: Drying shrinkage test may be skipped for bricks used under permanently damp conditions.

3. Rounding Off (Clause 3)

• Follow IS 2:1960 for rounding numerical values.
• Retain the same number of significant figures as specified.

4. Related Standards

• IS 3495 (Methods of test for burnt clay bricks)
• IS 3812 (Fly ash specification)
• IS 5454 (Sampling of burnt clay bricks)

flowchart LR
    A[Wet Length] --> B[Measure Dry Length]
    B --> C[Calculate Shrinkage %]
    C --> D[Compare with Table 1 Limits]
    D --> E{Conforms?}
    E -->|Yes| F[Accept Batch]
    E -->|No| G[Reject Batch]

This ensures quality control of calcium silicate bricks per IS 4139.

IS 4139: Physical Characteristics of Calcium Silicate Bricks

1. Dimensions & Tolerances (Clause 6.1)

• Standard sizes:
  • 190 mm × 90 mm × 90 mm
  • 190 mm × 90 mm × 40 mm
• Tolerances:
  • Length: ± 3 mm
  • Breadth & Height: ± 2 mm
• Other sizes allowed by agreement, same tolerances apply.

2. Classification by Compressive Strength (Clause 5.1)

3. Drying Shrinkage Limits (Clause 7.2 & Table 1)

• Shrinkage test may be skipped for bricks used under permanently damp conditions.

4. Drying Shrinkage Calculation (Annex A-5.1)

[ \text{Drying Shrinkage} = \frac{\text{Wet Length} - \text{Dry Length}}{\text{Wet Length}} \times 100% ]

• Average of 3 specimens used for batch evaluation.

This concise summary provides key physical specs, classification, and shrinkage criteria as per IS 4139.

IS 4139: Classification of Calcium Silicate Bricks

1. Classification by Compressive Strength (Clause 5.1)

2. Drying Shrinkage Limits (Clause 7.2, Table 1)

• Drying shrinkage test may be omitted for bricks used under permanently damp conditions.

3. Material Composition (Clause 4.1)

• Made from finely ground sand/siliceous rock and lime.
• Fly ash (IS 3812:1981) can be added in limited quantity.

Summary

• Classification is primarily based on compressive strength.
• Shrinkage limits decrease with higher strength classes.
• Proper rounding off of test results as per IS 2:1960 is mandatory.

flowchart TD
    A[Raw Materials: Sand + Lime + Fly Ash] --> B[Manufacturing Process]
    B --> C[Calcium Silicate Brick]
    C --> D{Check Compressive Strength}
    D -->|7.5 to <10| Class_7_5[Class 7.5]
    D -->|10 to <15| Class_10[Class 10]
    D -->|15 to <20| Class_15[Class 15]
    D -->|≥20| Class_20[Class 20]
    C --> E{Drying Shrinkage Test}
    E -->|Yes| Check_Shrinkage[Compare with class limits]
    E -->|No (damp conditions)| Skip_Test[No test needed]

IS 4139: Dimensions and Tolerances for Calcium Silicate Bricks

Key Specifications:

• Measuring Apparatus (Clause 2.1):

  • Use a micrometer or dial gauge accurate to 0.002 mm.
  • Gauge mounted on a frame with 5 mm diameter balls as reference points.
  • Invar steel rods with hemispherical ends (5 mm diameter) recommended for precise measurement.

• Classification by Compressive Strength (Clause 5.1):

• Tolerance Guidelines:
  • Final test values rounded as per IS 2:1960.
  • Dimensional tolerances are implied to be very tight due to the precise measurement method.

Drying Shrinkage Calculation (Annex A-5):

[ \text{Drying Shrinkage (%)} = \frac{\text{Wet Length} - \text{Dry Length}}{\text{Wet Length}} \times 100 ]

• Average drying shrinkage is the mean of three specimens.

Summary Diagram of Measurement Setup:

graph LR
A[Specimen] -->|5 mm ball| B[Measuring Frame]
B -->|Dial Gauge 0.001 mm| C[Reading]
B -->|5 mm ball| D[Specimen]

Note: Use calibrated instruments and follow IS 2 for rounding off numerical results.

IS 4139: Physical Characteristics of Calcium Silicate Bricks

1. Dimensions & Tolerances (Clause 6.1)

• Standard Sizes:
  • 190 mm × 90 mm × 90 mm
  • 190 mm × 90 mm × 40 mm
• Tolerances:
  • Length: ± 3 mm
  • Breadth & Height: ± 2 mm
• Other sizes allowed by agreement, same tolerances apply.

2. Compressive Strength Classes (Clause 5.1)

3. Drying Shrinkage Limits (Clause 7.2 & Table 1)

• Shrinkage calculated as:
  [ \text{Drying Shrinkage} = \frac{\text{Wet Length} - \text{Dry Length}}{\text{Wet Length}} \times 100 ]

4. Sampling & Conformity (Clause 8 & Annex A-5)

• Average drying shrinkage is mean of 3 specimens.
• Bricks under permanently damp conditions may skip shrinkage test.

flowchart TD
    A[Calcium Silicate Brick] --> B[Dimensions & Tolerances]
    B --> C{Size}
    C -->|Standard| D[190×90×90 or 190×90×40 mm]
    C -->|Other| E[By Agreement]
    A --> F[Physical Properties]
    F --> G[Compressive Strength Class]
    G --> H[7.5, 10,

IS 4139: Sampling and Criterion for Conformity

1. Sampling & Criterion Reference

• Sampling of bricks and conformity criteria are governed by IS 5454:1978 (Clause 8.1).
• Final test results should be rounded per IS 2:1960 rules, maintaining the same significant figures as specified values.

2. Drying Shrinkage Limits (Table 1, Clause 7.2)

• Drying shrinkage test may be skipped for bricks used under permanently damp conditions.

3. Measuring Apparatus (Annex A, Clause 2.1)

• Use a micrometer or dial gauge accurate to 0.002 mm.
• Gauge mounted in a frame with recessed ends seating on 5 mm diameter balls fixed on the specimen.
• Invar steel rod with hemispherical ends or steel balls ensures precise length measurement.

Summary:

• Follow IS 5454 for sampling.
• Round off results as per IS 2.
• Drying shrinkage limits depend on class designation.
• Use precise measuring apparatus with 0.002 mm accuracy.

flowchart LR
    A[Sampling as per IS 5454] --> B[Testing bricks]
    B --> C{Drying Shrinkage}
    C -->|Class 7.5 or 10| D[Max 0.06% shrinkage]
    C -->|Class 15 or 20| E[Max 0.04% shrinkage]
    B --> F[Measure length change]
    F --> G[Use micrometer gauge (0.002 mm)]
    G --> H[Result rounded as per IS 2]
    H --> I[Conformity decision]

IS 4139 - Marking (Clause 9.1) & Related Specifications

• Marking Requirement:
  Each brick shall be marked with:

  • Manufacturer's identification mark or initials
  • Class of brick

• Purpose:
  Ensures traceability and compliance with the standard.

Measurement & Testing (Related Clauses)

• Drying Shrinkage Calculation (Clause 5.1):
  [ \text{Drying Shrinkage (%)} = \frac{\text{Wet Length} - \text{Dry Length}}{\text{Wet Length}} \times 100 ]

  • Average of 3 bricks is taken as batch drying shrinkage.

• Measuring Apparatus (Clause 2.1):

  • Use a micrometer or dial gauge accurate to 0.002 mm.
  • Gauge mounted on a frame with 5 mm diameter steel balls as reference points on specimens.
  • Use Invar steel rods with hemispherical ends or steel balls for precise length measurement.

Summary Table for Marking

flowchart TD
    A[Brick Sample] --> B[Mark with Manufacturer ID & Class]
    B --> C[Measure Wet Length]
    C --> D[Dry Brick]
    D --> E[Measure Dry Length]
    E --> F[Calculate Drying Shrinkage %]

This marking and measurement ensure quality control and standard compliance per IS 4139.

IS 4139: Method for Determination of Drying Shrinkage of Calcium Silicate Bricks

Key Specifications & Formulas:

• Test Specimen: As per Annex A (Clause 7.2), specimens are dried with free air access; no wet specimens placed simultaneously in the oven (Clause A-4.4).

• Drying Shrinkage Calculation (Clause 5.1, Table A-5):

[ \text{Drying Shrinkage (%)} = \frac{L_{\text{wet}} - L_{\text{dry}}}{L_{\text{wet}}} \times 100 ]

Where:

• (L_{\text{wet}}) = Length of specimen before drying

• (L_{\text{dry}}) = Length of specimen after drying

• Average drying shrinkage is the mean of three specimens.

Acceptable Drying Shrinkage Limits (Table 1, Clause 7.2):

Note: Drying shrinkage test is not required for bricks used under permanently damp conditions.

flowchart TD
    A[Test Specimen Preparation] --> B[Measure Wet Length \(L_{wet}\)]
    B --> C[Dry Specimen (free air access)]
    C --> D[Measure Dry Length \(L_{dry}\)]
    D --> E[Calculate Drying Shrinkage %]
    E --> F[Compare with Table 1 Limits]
    F --> G{Conforms?}
    G -->|Yes| H[Accept Batch]
    G -->|No| I[Reject Batch]

This method ensures quality control by limiting dimensional changes due to drying, critical for brick performance.