Ceramic Tiles-Methods of Test, Sampling and Basis of Acceptance, Part 1: Determination of Dimensions and Surface Quality

IS 13630 Part 1: Scope Overview

• Scope Definition: IS 13630 Part 1 primarily covers guidelines and requirements for structural design and detailing of specific construction elements (e.g., concrete, steel, or composite structures). It ensures safety, serviceability, and durability.

• Rounding Off Rules:
  As per IS 2:1960, all calculated or observed values must be rounded off to the same number of significant figures as specified in the standard. This ensures consistency in reporting test or analysis results.

• Referenced Standards:
  The standard draws upon related IS codes for comprehensive design criteria, such as IS 456 for concrete or IS 800 for steel, depending on the material.

Key Points for Scope (Generalized):

If you need formulas or tables for a specific element (e.g., load calculations, reinforcement detailing), please specify the section or element type.

IS 13630 Part 1: Measurements of Length and Width

Key Specifications:

• Ignore spacer lugs, glaze bobs, and irregularities hidden in joints (Clause 1.3).
• Tiles with area < 400 mm² are excluded from length, width, thickness, straightness, rectangularity, and flatness measurements (Clause 1.2).

Measurement Procedure (Clause 2.4):

• Square tiles: Average dimension = mean of 4 side measurements.
• Oblong tiles: Average dimension per side = mean of 2 measurements per similar side.
• Sample average = mean of 40 measurements.
• Length and width averages = mean of 20 measurements each.

Rectangularity (Clause 5.5):

• Expressed as a percentage of length and width for oblong tiles.
• For square tiles, expressed as a percentage of the tile size.

Summary Table for Measurement Averages:

Rectangularity Formula:

[ \text{Rectangularity (%)} = \frac{|L - W|}{\text{Reference dimension}} \times 100 ]

• For oblong tiles, reference dimension = length or width.
• For square tiles, reference dimension = tile size.

flowchart LR
    A[Tile] --> B{Tile Type}
    B -->|Square| C[Measure 4 sides]
    B -->|Oblong| D[Measure 2 sides per pair]
    C --> E[Average 4 sides per tile]
    D --> F[Average 2 sides per pair]
    E --> G[Average of 40 tiles]
    F --> H[Average of 20 measurements per dimension]
    G --> I[Calculate rectangularity %]
    H --> I

This ensures consistent and standardized measurement of tile dimensions per IS 13630 Part 1.

IS 13630 Part 1: Test Specimens and Sampling

• Number of Specimens:
  As per Clauses 2.2, 3.2, 4.3, and 6.3, 10 whole tiles of each type shall be tested. This ensures statistical reliability in test results.

• Sampling Procedure:

  • Tiles should be randomly selected to represent the batch.
  • Specimens must be free from visible defects unless testing for such defects.
  • The size and type of tiles must conform to the specifications for the intended test.

• Key Points:

  • Testing is done on whole tiles, not fragments.
  • The sample size (10 tiles) is consistent across various clauses, emphasizing uniformity.

No specific formula is required for sampling; the standard mandates 10 whole tiles per type as the minimum sample size.

flowchart LR
    A[Batch of Tiles] --> B[Random Sampling]
    B --> C[Select 10 Whole Tiles]
    C --> D[Test Specimens]
    D --> E[Evaluate Results]

This ensures representativeness and reliability in tile quality assessment.

IS 13630 Part 1: Measurements of Straightness of Sides

Key Definitions (Clause 4.1.2)

• Straightness of Sides: Deviation of the center line of a tile side from a perfectly straight line in the tile plane.
• Applies only to straight sides of tiles.
• Ignore spacer lugs, glaze bobs, and irregularities hidden after fixing (Clause 1.3).

Apparatus (Clauses 4.2.1 & 5.2.1)

• Use a dial gauge mounted on:
  • A straight edge or steel square (Fig. 1 in IS 13630-1).
• Dial gauge measures deviation as the straight edge is moved along the tile side.

Measurement Procedure

1. Place the tile on a flat surface.
2. Position the straight edge along the tile side.
3. Move the dial gauge along the side to record deviation.
4. The maximum deviation from the zero reading is the straightness error.

Typical Specification Limits (from IS 13630 and best practice)

Summary Diagram (Mermaid.js)

flowchart LR
    A[Tile Side] --> B[Straight Edge]
    B --> C[Dial Gauge measures deviation]
    C --> D[Record max deviation = Straightness error]

Note: Always ensure the dial gauge is calibrated and the tile is clean and free from surface irregularities affecting measurement.

Measurement of Rectangularity (IS 13630 Part 1:2006)

Key Definitions:

• Rectangularity: Deviation of a tile's corner from a perfect right angle.
• Measured by placing the tile corner against a precise calibrating plate angle.

Formula (Clause 5.1.2):

[ \text{Rectangularity deviation (%)} = \frac{8}{L} \times 100 ]

Where:

• (L) = Length of the adjacent sides of the tile (in mm)
• (8) = Deviation of the outer corner from the plate (measured 5 mm from the corner, in mm)

Expression of Results (Clause 5.5):

• For oblong tiles: Rectangularity deviation expressed as a percentage of length and width.
• For square tiles: Expressed as a percentage of the tile size.

Test Report Must Include (Clause 4.5):

• Tile description
• Straightness measurements of sides
• Maximum deviation from straightness (%) relative to work sizes

flowchart LR
    A[Place tile corner against calibrating plate angle]
    B[Measure deviation (8) 5 mm from corner]
    C[Measure length of adjacent sides (L)]
    D[Calculate deviation % = (8/L)*100]
    E[Express deviation as % of length/width or size]
    A --> B --> C --> D --> E

This method ensures precise quantification of rectangularity for quality control of ceramic tiles.

IS 13630 Part 1: Surface Flatness (Curvature and Warpage) Key Points

Definitions (Clause 6.1.1 & 6.1.2)

• Surface flatness is measured by curvature and warpage on ceramic tiles.
• Measurements are taken at three positions on the tile surface.
• If the top surface has relief, measure on the back surface.

Measurement Parameters (Clause 6.6)

The test report must include:

Calculation of Curvature and Warpage

• Curvature (C) and Warpage (W) are deviations from a reference flat plane.
• Expressed as:

[ \text{Curvature or Warpage (%)} = \frac{\text{Max deviation (mm)}}{\text{Reference length (mm)}} \times 100 ]

• Reference length is typically the diagonal or edge length of the tile.

Summary Table for Reporting

Visualization of Measurement Positions

graph TD
  A[Tile Surface]
  A --> B(Centre Curvature Measurement)
  A --> C(Edge Curvature Measurement)
  A --> D(Warpage Measurement over entire surface)

Note: Use precision instruments like straight edges and feeler gauges or laser flatness testers for accurate measurement.

IS 13630 Part 1: Test Reports and Expression of Results

1. Test Report Contents (Clauses 2.5, 5.6, 7.6)

• Tile Description: Type, size, shape.
• Measurements:
  • Length & width of each tile.
  • Average size of 10 specimens (square/oblong).
  • Thickness and rectangularity measurements.
• Deviations:
  • Percent deviation from work size and average size (2 or 4 sides).
  • Maximum deviation from rectangularity (% related to work size).
• Surface Flatness (Curvature & Warpage):
  • Number and area of tiles tested.
  • Assessment criteria.
  • Percentage of defect-free tiles.

2. Key Formulas for Deviations & Curvatures

3. Expression of Results (Clause 6.5)

• Results expressed as average sizes, deviations (%) from nominal/work sizes.
• Flatness and warpage results expressed as percentage deviations relative to tile dimensions.
• Defect percentages reported for quality control.

flowchart TD
    A[Test Specimens] --> B[Measurements]
    B --> C{Measurements}
   

IS 13630 Part 1 — Terminology Key Points

The terminology clauses (4.1, 5.1, 6.1, 6.1.1) define essential terms for ceramic tile measurement, especially surface flatness.

Key Definitions (Clause 6.1.1) for Surface Flatness:

• Curvature: The deviation of the tile surface from a flat plane, measured as the maximum height difference along the tile's length or width.
• Warpage: The distortion of the tile surface causing it to bend or twist out of plane, measured as the maximum height difference diagonally across the tile.
• Surface Flatness Measurement: Quantified by measuring the maximum gap between the tile surface and a straightedge or a reference plane.

Measurement Specifications:

• Use a straightedge of length equal to the tile size.
• Measure gaps at multiple points to determine max deviation.
• Flatness limits depend on tile size and type (refer to IS 13630 Part 1 tables).

Typical Flatness Limits (Indicative):

flowchart LR
    A[Tile Surface] --> B[Measure Curvature]
    A --> C[Measure Warpage]
    B --> D{Max height difference along length/width}
    C --> E{Max height difference diagonally}
    D --> F[Compare with flatness limits]
    E --> F

Summary: IS 13630 Part 1 defines flatness terms precisely for ceramic tiles to ensure quality control by measuring curvature and warpage using straightedges and limiting deviations as per tile size.

IS 13630 Part 1: Apparatus and Calibration Key Points

• Apparatus Selection (6.4.1.1):
  Choose apparatus sized correctly for the test; place the calibrating plate precisely on three accurately positioned studs.

• Calibrating Plate (6.2.1.2):

  • Material: Metal or glass
  • Thickness: Minimum 10 mm
  • Must be true flat to ensure accurate calibration.

• Measurement Tools (2.1):
  Use vernier calipers or equivalent for precise linear measurements.

• Calibration Procedure (5.4.2):
  Insert the calibrating plate exactly, then adjust the dial gauge to a known reference reading.

Calibration Setup Summary

flowchart TD
    A[Select Apparatus] --> B[Place Calibrating Plate on 3 Studs]
    B --> C[Measure Plate Thickness (≥10 mm)]
    C --> D[Insert Plate in Instrument]
    D --> E[Adjust Dial Gauge to Known Value]

This ensures accurate calibration for reliable measurement results as per IS 13630 Part 1.

Basis of Acceptance per IS 13630 (Part 1):

The acceptance of ceramic tiles is based on test reports and specified tolerances:

Key Test Report Contents (Clause 7.6 & 2.5):

• Description of tiles.
• Number and area of tiles tested.
• All length and width measurements.
• Average size per tile (square or oblong).
• Percentage deviation from work size and average size of test specimens.
• Percentage of tiles without defects.

Dimensional Deviations:

• Straightness of sides: Deviation = C/L (Fig. 3)
• Rectangularity: Deviation = 8/L (Fig. 4)
• Centre curvature: Ac/D (Fig. 5)
• Edge curvature: As/L (Fig. 6)
• Warpage: Aw/D (Fig. 7)

Where:

• L = length of tile side
• D = diagonal length
• C, Ac, As, Aw = measured deviations as per figures

Rounding Off:

• Final test values rounded per IS 2:1960, matching significant figures of specified values.

Summary Table for Dimensional Deviations:

This ensures tiles meet quality and dimensional standards before acceptance.