Burnt clay fly ash building bricks-Specification

IS 13757 Scope Summary:

• Purpose: Defines requirements for brick dimensions, shapes, and testing, ensuring compliance by rounding off results per IS 2:1960.
• Reference Standards: Uses definitions from IS 2248:1981 and related standards listed in Annex A.
• Classification: Covers modular and non-modular brick sizes.

Key Specifications (Clause 6.1.2)

• These are non-modular brick sizes allowed.
• Dimensions are in millimetres.
• Frogs (indentations on bricks) shapes and sizes are illustrated in Fig. 1A and 1B (refer to IS 13757 for details).

Rounding Off Rule (IS 2:1960)

• Final test or analysis values must be rounded to the same number of significant figures as the specified value.

flowchart TD
    A[Start: Brick Testing] --> B{Measure Dimensions}
    B --> C[Round off values per IS 2:1960]
    C --> D{Check compliance with IS 13757 sizes}
    D -->|Yes| E[Brick accepted]
    D -->|No| F[Brick rejected]

This concise scope ensures bricks meet dimensional and quality norms for construction use.

IS 13757 - References: Key Specifications & Tables

1. Rounding Off (IS 2:1960)

• Final test/analysis results must be rounded off per IS 2 rules.
• Retain significant places equal to those in the specified value.

2. Referenced Indian Standards (Annex A)

3. Brick Dimensions (Clause 6.1.2)

(Figures 1A & 1B illustrate frog shapes and sizes)

Summary

• Use IS 2:1960 for rounding test results.
• Refer to Annex A IS codes for detailed manufacturing and testing.
• Brick sizes include 230×110×70 mm and 230×110×30 mm non-modular bricks.

flowchart LR
    A[IS 13757 Standard]
    A --> B[IS 2:1960 Rounding Rules]
    A --> C[Annex A: Referenced IS Codes]
    C --> C1[IS 1077, 2117, 2180, 2248, 3495, 3812, 5454]
    A --> D[Brick Dimensions]
    D --> D1[230×110×70 mm]
    D --> D2[230×110×30 mm]

This ensures compliance and quality control for burnt clay bricks per IS standards.

IS 13757 Definitions Summary

• Reference for Definitions:
  Clause 3.1 states that all definitions are as per IS 2248:1981 (currently under revision). IS 13757 does not provide standalone definitions but defers to IS 2248.

• Rounding Off Values:
  Clause 4 specifies rounding off test or analysis results per IS 2:1960.

  • Retain the same number of significant digits as the specified value.
  • Ensures consistency in reporting values.

• Brick Dimensions (Clause 6.1.2):
  Non-modular brick sizes allowed:

  Length (mm)	Width (mm)	Height (mm)
  230	110	70
  230	110	30

• Additional References:
  Annex A lists related Indian Standards necessary for full compliance.

Summary Table: Non-Modular Brick Sizes (Clause 6.1.2)

Note: For detailed definitions, consult IS 2248:1981. For rounding rules, refer to IS 2:1960.

IS 13757: Classification of Burnt Clay Fly Ash Bricks

1. Classification Basis (Clause 4.1)

Bricks are classified by average compressive strength as follows:

2. Rounding Off (General Quality)

• Test results should be rounded off per IS 2:1960.
• Retain the same number of significant digits as the standard value.

3. Fly Ash Content (Clause 12.5)

• Fly ash content allowed:
  • Up to 12.5 class: max 10% by weight
  • Above 12.5 class: max 15% by weight

This classification helps in selecting bricks for structural requirements based on strength.

IS 13757: General Quality Requirements for Burnt Clay-Fly Ash Bricks

1. Rounding Off (IS 2:1960)

• Final test/analysis values must be rounded to the same significant figures as the specified standard values.

2. Classification by Compressive Strength (Clause 4.1, Table 1)

3. Dimensional Tolerances (Clause 6.2.1)

• Modular Size Bricks (mm):

  Dimension	Range	Nominal ± Tolerance
  Length	3720 to 3880	3800 ± 80
  Width	1760 to 1840	1800 ± 40
  Height (90 mm bricks)	1760 to 1840	1800 ± 40
  Height (40 mm bricks)	760 to 840	800 ± 40

• Non-Modular Size Bricks (mm):

  Dimension	Range	Nominal ± Tolerance
  Length	4520 to 4680	4600 ± 80
  Width	2160 to 2240	2200 ± 40

IS 13757: Dimensions and Tolerances for Clay Building Fly Ash Bricks

1. Standard Modular Sizes (Clause 6.1.1)

2. Non-Modular Sizes (Clause 6.1.2)

3. Specifications (Clause 5.3)

• Bricks must have smooth rectangular faces with sharp corners.
• Uniformity in shape and colour is mandatory.

4. Rounding Off (General)

• Final test values must be rounded off as per IS 2:1960.
• Retain the same number of significant digits as the specified values.

Summary:

• Use modular sizes (190x90x90 mm or 190x90x40 mm) for standard bricks.
• Non-modular sizes (230x110x70 mm or 230x110x30 mm) are also permitted.
• Maintain sharp corners and uniformity.
• Follow IS 2 for rounding test results.

flowchart LR
    A[Bricks] --> B[Dimensions]
    B --> C[Modular Sizes]
    B --> D[Non-Modular Sizes]
    C --> |190x90x90| E[Standard Brick]
    C --> |190x90x40| F[Thin Brick]
    D --> |230x110x70| G[Large Brick]
    D --> |230x110x30| H[Thin Large Brick]
    A --> I[Surface Quality]
    I --> J[Smooth Faces]
    I --> K[Sharp Corners]
    I --> L[Uniform Shape & Colour]

IS 13757: Physical Requirements for Bricks - Key Specifications

1. Dimensional Tolerances (Clause 6.2.1)

Dimensions of 20 bricks measured in a straight line must be within these limits:

2. Measurement Procedure

• Arrange 20 bricks in a straight line, in contact.
• Measure total length with a steel tape or inextensible measure in one stretch.
• If impractical, divide into rows of 10 bricks and measure separately.
• Remove blisters, loose clay, and projections before measurement.

3. Rounding Off (Clause 7)

• Final test values should be rounded as per IS 2:1960.
• Retain significant figures equal to those in the specified value.

4. Frog Dimensions (Clause 6.1.2, Fig. 1)

Non-modular brick frogs:

flowchart LR
    A[Select 20 bricks randomly] --> B[Remove blisters & loose particles]
    B --> C[Arrange bricks in a straight line]
    C --> D[Measure total length with steel tape]
    D --> E{Length within tolerance

IS 13757: Sampling and Criterion for Conformity

• Sampling Procedure:
  Sampling of clay-flyash building bricks shall follow IS 5454 : 1978. This standard details the method to select representative samples for testing.

• Criterion for Conformity:
  The acceptance or rejection of the lot is based on criteria given in IS 5454 : 1978, which typically includes:

  • Sample size (n)
  • Acceptance number (Ac)
  • Rejection number (Re)

  These depend on lot size and quality level.

• Rounding Off:
  Test results shall be rounded as per IS 2 : 1960, keeping the same number of significant figures as the specified value.

• Efflorescence Limits:
  According to IS 3495 (Part 3) : 1992:

  • Up to Class 12.5 bricks: Efflorescence rating ≤ Moderate
  • Above Class 12.5 bricks: Efflorescence rating ≤ Slight

Summary Table (based on IS 5454 sampling concept)

(Exact values to be confirmed from IS 5454 : 1978)

flowchart TD
    A[Start: Lot of Bricks] --> B[Sampling as per IS 5454]
    B --> C[Test Samples as per IS 13757]
    C --> D{Test Results}
    D -->|Within Acceptance Criteria| E[Lot Accepted]
    D -->|Exceeds Rejection Criteria| F[Lot Rejected]
    E --> G[Use Bricks]
    F --> H[Reject or Reprocess]

For detailed sampling tables and acceptance criteria, refer directly to IS 5454 : 1978.

IS 13757 - Marking of Common Burnt Clay Building Bricks

Key Specifications on Marking (Clause 9.1):

• Each brick shall be marked with the manufacturer's identification mark or initials.
• Marking is typically done in the frog (the depression on one face of the brick).
• The manufacturer may also use the Standard Mark (Clause 9.1.1) to indicate compliance.

Purpose of Marking:

• Ensures traceability of the product.
• Assures conformity to the Indian Standard under BIS supervision.
• Helps in quality control and inspection.

Rounding Off (for test results):

• Follow IS 2:1960 rules for rounding off numerical values.
• The number of significant figures retained should match the specified value.

Summary Table for Marking:

Additional Notes:

• Marking aids in maintaining quality assurance under BIS licensing.
• Marked bricks are subject to continuous BIS checks for conformity.

flowchart LR
    A[Brick] --> B[Frog]
    B --> C[Manufacturer's Mark/Initials]
    C --> D[Traceability & Quality Control]
    D --> E[Compliance with IS 13757]

This ensures bricks can be identified and verified for quality as per IS 13757.