Burnt clay flat terracing tiles- Specification, Part 1: Machine made

IS 2690 Part 1: Scope Summary

• Scope: Covers testing and quality requirements for specific tiles (details depend on tile type).
• Reference Standards: Uses definitions from IS 2248:1992.
• Rounding Off: Results must be rounded as per IS 2:1960 rules, retaining the same significant figures as specified.
• Test Result Calculation: Average values should be computed as per Clause 4.2.
• Span (X): Defined as per tile size for testing.
• Apparatus: Details for bearer supports (A & B) and test setup for transverse testing are specified (see Fig. 2).

Key Points for Compliance

Formula for Average Value (Clause 4.2)

[ \text{Average Value} = \frac{\sum \text{Test Results}}{n} ]

Where n = number of test samples.

Diagram: Test Setup Essentials (Simplified)

graph LR
A[Bearer A] -- Span X --> B[Tile Sample]
B -- Span X --> C[Bearer B]

For detailed apparatus dimensions and test procedures, refer directly to IS 2690 Part 1:1993 and IS 2248:1992.

IS 2690 Part 1 (1993) - Key References and Formulas

1. Calculation of Average Value (Clause 4.2)

• Average value ( \bar{X} ) of test results is calculated as:

  [ \bar{X} = \frac{\sum X_i}{n} ]

  where ( X_i ) = individual test result, ( n ) = number of tests.

• Round off final results as per IS 2:1960 rules, keeping significant figures consistent with specified values.

2. Test Setup for Flexural Strength (Clause 3.1.2 & Annex B)

• Support span ( X ) = 3/4 of tile dimension (longer face for rectangular tiles).
• Load applied perpendicular to span at 45 to 55 kg/min.
• Support bearers must ensure uniform load distribution.

3. Apparatus Essentials (Fig. 1 & Fig. 2)

• Tile testing machine includes:
  • Bearers A & B supporting tile.
  • Load application mechanism with trigger.
  • Containers for lead shots (load increments).
  • Springs and bolts for support adjustments.

4. Contact & Amendments

• BIS offices and contact numbers are provided for updates.
• Amendments issued post-publication should be checked for latest standards.

Summary Table for Flexural Strength Test Setup

flowchart LR
    A[Tile Specimen] --> B[Bearers (Span = 3/4 tile length)]
    B --> C[Load Applied Perpendicular]
    C --> D[Load Increment via Lead Shots]
    D --> E[Measure Deflection & Failure Load]
    E --> F[Calculate Average Strength]

This concise guide aligns with IS 2690 Part 1 for flexural strength testing of roofing tiles.

IS 2690 Part 1 (1993) - Definitions & Key Specifications

• Reference for Definitions:
  Clause 3.0 states that definitions are as per IS 2248:1992 (Glossary of terms relating to structural clay products).

• Rounding Off Rules:
  Results of tests or analyses must be rounded off following IS 2:1960 rules, maintaining the same number of significant figures as specified values.

• Average Value Calculation:
  Clause 4.2 and Table B-4 specify that average test results should be calculated as the arithmetic mean of individual values.

• Span (X):
  Defined as per tile size for transverse testing apparatus (see Fig. 2 in IS 2690 Part 1).

Summary Table: Key References for Definitions & Calculations

Formula: Average Value Calculation

[ \text{Average} = \frac{\sum_{i=1}^n X_i}{n} ]

Where:

• (X_i) = individual test result
• (n) = number of tests

If you need detailed definitions, refer directly to IS 2248:1992 for terminology related to structural clay products.

IS 2690 Part 1 - General Quality: Key Points

• Rounding off Test Results (Clause 4):
  Final test values must be rounded per IS 2:1960 rules, retaining the same number of significant figures as the specified standard value.

• Calculation of Average (Clause 4.2):
  Average value ( \bar{X} ) is calculated from test results for reporting compliance:
  [ \bar{X} = \frac{1}{n} \sum_{i=1}^n X_i ]

• Reference for Definitions (Clause 3.0):
  Use definitions from IS 2248:1992 for terms related to quality and testing.

• Apparatus Essentials (Fig. 2):
  The standard specifies bearer details and span based on tile size for transverse testing.

• Water Absorption Test (Annex A, Clause 6.1):
  Details test specimens and procedure to assess tile water absorption, critical for quality control.

Summary Table: Test Result Reporting

flowchart LR
    A[Test Specimen] --> B[Conduct Test]
    B --> C[Record Values]
    C --> D[Calculate Average \(\bar{X}\)]
    D --> E[Round off per IS 2:1960]
    E --> F[Compare with Specified Value]
    F --> G{Complies?}
    G -->|Yes| H[Accept Quality]
    G -->|No| I[Reject / Re-test]

This ensures consistent quality evaluation per IS 2690 Part 1.

IS 2690 Part 1: Key Specifications for Terracing Tiles

Dimensions & Shape

• Tiles must be uniform in shape and size.
• Faces: Plain or grooved.
• Back: Corrugated for mortar adhesion.

Tolerances (Clause 5.1.4)

Warpage (Clause 5.2.1)

• Maximum warpage ≤ 1% of tile dimension.
• Measurement method:
  • Place a straight-edge on tile over a flat surface.
  • Measure max gap using a metallic wedge.

Summary Table

flowchart LR
    A[Terracing Tile] --> B[Uniform Shape & Size]
    A --> C[Face: Plain or Grooved]
    A --> D[Back: Corrugated]
    A --> E[Tolerances]
    E --> F[Pressed: ±2%]
    E --> G[Extruded: ±3%]
    A --> H[Warpage ≤ 1%]
    H --> I[Measured by straight-edge & wedge]

This ensures tile quality for proper installation and durability.

IS 2690 Part 1: Water Absorption Key Points

Water Absorption Calculation (Clause 3.1)

[ \text{Percentage Water Absorption} = \frac{B - A}{A} \times 100 ]

• A = Weight of dry specimen (g)
• B = Weight after 24 hours immersion in cold water (g)

Reporting (Clause 3.2)

• Average percentage water absorption of multiple tiles is reported as the final value.

Test Specimens (Annex A, Clause 6.1)

• Specimens should be dried and weighed accurately before immersion.
• Immersion duration: 24 hours in cold water.

Additional Specification (Clause 5.2.1)

• Maximum warpage ≤ 1% of tile dimension.
• Measure warpage using a straight-edge and metallic wedge.

Summary Table

flowchart TD
    A[Dry Tile Weight (A)] --> B[Immerse 24 hrs in cold water]
    B --> C[Wet Tile Weight (B)]
    C --> D[Calculate Water Absorption %: ((B - A)/A)*100]
    D --> E[Report Average Water Absorption]

This ensures tile quality by limiting porosity and dimensional stability.

Flexural Strength as per IS 2690 Part 1

Key Formula (Clause 4.1: B-4.1)

[ \text{Flexural Strength} = \frac{150 \times W \times S}{b \times t^2} \quad \text{kg/cm}^2 ]

Where:

• W = Breaking load (kg)
• S = Span (mm) = 3/4 × length of tile
• b = Width of tile (mm)
• t = Thickness of tile (mm)

Test Setup (Clause 3.1.2 & Annex B)

• Tile supported flat-wise on bearers with span = 3/4 length of tile
• Support along longer face for rectangular tiles
• Load applied perpendicular to span at 45-55 kg/min
• Uniform load distribution ensured by packing between tile and bearers

Additional Specifications

• Average water absorption ≤ 15% (Clause 6.1)
• Test specimens: 6 tiles (Annex B-1)
• Use tile testing machine as per Fig. 1 (dimensions and components detailed in IS 2690 Part 1)

Summary Table for Flexural Strength Calculation

flowchart LR
    A[Tile] --> B[Support on Bearers (Span = 3/4 length)]
    B --> C[Apply Load Perpendicular to Span]
    C --> D[Measure Breaking Load W]
    D --> E[Calculate Flexural Strength using Formula]

This method ensures consistent and reliable determination of roofing tile flexural strength per IS 2690 Part 1.

IS 2690 Part 1: Sampling and Testing Summary

Sampling Procedure (Clause 8.1)

• Minimum 6 tiles randomly selected per 1000 tiles or fraction thereof in a lot.
• Minimum 15 tiles must be tested per lot.
• Additional samples may be taken at purchaser's discretion.

Testing & Reporting (Clause 4.2, Table B-4)

• Calculate average value of test results.
• Round off results as per IS 2:1960 rules.
• Retain significant figures same as specified values.

Key Specification for Strength (Clause 7.1)

• Average Modulus of Rupture (MOR) for 6 tiles ≥ 2 N/mm² (bending test per Annex B).

Sampling Formula:

[ \text{Number of samples} = \max(15, , 6 \times \lceil \frac{\text{Number of tiles in lot}}{1000} \rceil) ]

Testing Apparatus (Fig. 2 Essentials)

• Two bearers support tile.
• Load applied at center span = tile size (X).
• Transverse bending test to determine MOR.

Summary Table: Sampling and Testing

flowchart LR
    A[Lot of Tiles] --> B{Number of Tiles > 1000?}
    B -- Yes --> C[Samples = 6 × number_of_1000s]
    B -- No --> D[Samples = 6]
    C --> E{Samples < 15?}
    D --> E
    E -- Yes --> F[Samples = 15]
    E -- No --> G[Samples as calculated]
    F --> H[Conduct Tests]
    G --> H
    H --> I[Calculate Average MOR]
    I --> J{MOR ≥ 2 N/mm²?}
    J -- Yes --> K[Pass]
    J -- No --> L[Fail]

This concise summary covers sampling size, testing

IS 2690 Part 1 (1993) — Marking of Terracing Tiles

Key Specifications (Clause 9.1 & 9.1.1):

• Each terracing tile shall be legibly and indelibly marked with:
  • Source of manufacture
  • Letter 'M' to indicate the tile is machine made
• Marking area shall not exceed 5% of the tile surface.
• Tiles may bear the Standard Mark as per BIS licensing and quality control norms.

Important Notes on Marking:

• The Standard Mark assures compliance with IS 2690 under BIS supervision.
• Marking must be durable and visible without impairing tile performance.
• Use IS 2:1960 rounding rules for test results related to marking compliance.

Summary Table: Marking Requirements

Additional Reference:

• Clause 4.2: Average test values for marking-related tests to be calculated as per Table B-4.
• For licensing details, contact BIS regional offices listed in the standard.

flowchart LR
    A[Tile Surface] --> B{Marking Area ≤ 5%?}
    B -- Yes --> C[Mark Source + 'M' (Machine Made)]
    B -- No --> D[Reduce Marking Area]
    C --> E[Apply Standard Mark (Optional)]

This ensures traceability and quality assurance for terracing tiles under IS 2690 Part 1.

IS 2690 Part 1: Water Absorption Test Key Points

Test Procedure (Clause A-2.1)

• Dry tile specimens in an oven at 100–110°C until constant weight.
• Cool and weigh the dry specimen (A).
• Immerse specimen fully in clean water at 24–30°C for 24 hours.
• Remove, wipe surface water carefully, and weigh wet specimen (B) within 3 minutes.

Formula for Water Absorption (Clause A-3.1)

[ \text{Percentage Water Absorption} = \frac{B - A}{A} \times 100 ]

Where:

• A = weight of dry specimen (g)
• B = weight after 24-hour immersion (g)

Reporting (Clause A-3.2)

• Calculate average water absorption from multiple specimens.
• Report as percentage water absorption.

Summary Table

This test ensures tiles meet durability and quality standards by limiting water absorption.

Determination of Flexural Strength as per IS 2690 Part 1

Key Formula (Clause B-4.1):

[ \text{Flexural Strength} = \frac{150 \times W \times S}{b \times t^2} \quad \text{kg/cm}^2 ]

• W = Breaking load (kg)
• S = Span (mm) = 3/4 × tile length
• b = Width of tile (mm)
• t = Thickness of tile (mm)

Test Setup (Clause B-3.1.2):

• Tile supported flat-wise on bearers.
• Span = 3/4 of tile length.
• Load applied perpendicular to span at 45–55 kg/min.
• Packing used for uniform load distribution.

Additional Specifications:

• Average water absorption of 6 tiles ≤ 15% (Clause 6.1).
• Use tile testing machine as per Fig. 1 with specified MS components.

Summary Table for Flexural Strength Calculation:

flowchart LR
    A[Tile Specimen] --> B[Support on Bearers (Span = 3/4 length)]
    B --> C[Load Applied Perpendicular at 45-55 kg/min]
    C --> D[Breaking Load (W)]
    D --> E[Calculate Flexural Strength using formula]

Use this formula and procedure to determine flexural strength reliably as per IS 2690 Part 1.