Bamboo Mat Corrugated Sheets -Specification

IS 15476 Scope: Key Specifications and Tables

• Scope: Covers dimensions, tolerances, sampling, and testing for corrugated sheets and related materials.

1. Dimensions & Tolerances (Clause 6.1, Table 1)

• Thickness measured as average of 6 random readings (excluding valleys).
• Depth measured with depth gauge; deviation within tolerance.
• Pitch tolerance applies over six pitches total length.

2. Sampling & Acceptance (Clause 9.2.1, Table 3)

3. Testing (Annex & Clause 6)

• Density test: 3 specimens, 300x300 mm, conditioned at 65±5% RH and 27±2°C.
• Weight accuracy: 1 g.
• Dimensions measured post-conditioning.

flowchart TD
    A[Lot Size] --> B{Sample Size}
    B -->|Dimensional| C[Acceptance Number]
    B -->|Other| D[Acceptance Number]
    C --> E[Pass/Fail]
    D --> E

Summary: IS 15476

IS 15476 - Key References, Tables & Specifications

1. Sample Size & Acceptance Criteria (Clause 9.2.1, Table 3)

2. Dimensions & Tolerances (Clause 6.1.1, Table 1)

• Thickness: Average of 6 random measurements (excluding valleys).
• Depth: Measured by depth gauge; deviation within tolerance.
• Pitch: Measured over 6 pitches; total length must be within tolerance.

3. Requirements of Bamboo Mat Corrugated Sheets (BMCS) (Clause 8.1, Table 2)

IS 15476: Definitions and Key Specifications

1. Definitions (Clause 3.1)

• Definitions are as per IS 707, IS 6874, IS 13958, plus additional ones in IS 15476.
• Refer to IS 707 for timber-related terms and IS 6874 for bamboo testing.

2. Sample Size & Acceptance Criteria (Table 3, Clause 9.2.1)

• Lot conforms if defectives ≤ acceptance number.

3. Dimensions & Tolerances (Table 1, Clause 6.1.1)

• Thickness = average of 6 random measurements (excluding valleys).
• Depth measured with depth gauge; pitch measured over 6 corrugations.

4. Key Property Requirements (Table 2, Clause 8.1)

IS 15476: Key Formulas, Tables & Specifications for Materials (Clause 8.1)

Table 2: Requirements of Bamboo Mat Corrugated Sheets (BMCS)

Important Test Conditions & Notes:

• Density Calculation: Average of 3 specimens (300x300 mm), conditioned at 27±2°C, 65±5% RH.
• Water Absorption: Specimens submerged under 25 mm water at 27±2°C for 24h.
• Cyclic Test: 3 cycles of 4h boiling + 16h drying at 65±2°C.
• Falling Weight Test: Whole sheet ≥1.2 m, conditioned 5 days at 27±2°C, 65±5% RH.

Dimensions & Tolerances (Clause 6.1.1, Table 1)

IS 15476: Manufacture - Key Formulas, Tables & Specifications

1. Dimensional Requirements (Clause 6.1 & Table 1)

• Thickness is average of 6 random measurements (except valleys).
• Depth measured with depth gauge; pitch measured over 6 corrugations.

2. Sample Size & Acceptance Criteria (Clause 9.2.1, Table 3)

• Lot accepted if defectives ≤ acceptance number.

3. Physical & Mechanical Requirements (Clause 8.1, Table 2)

Summary

IS 15476: Dimensions and Tolerances for Corrugated Sheets

Key Dimensions (All in mm) — Table 1 (Clause 6.1.1)

Tolerances

• Length, Width: ±10 mm
• Thickness: ±10%
• Depth of Corrugation: +2 mm / -0 mm
• Pitch of Corrugation: ±2 mm (measured over six pitches)

Measurement Notes:

• Thickness is average of 6 random width-wise measurements (excluding valleys).
• Depth measured on 6 corrugations randomly; deviation must be within tolerance.
• Pitch tolerance applies over six pitches; total length over six pitches must be within ±2 mm of 6 × pitch.

Additional:

• Alternate corrugation designs allowed by mutual agreement with specified tolerances.
• Dimensional checks per Clause 9.1.3 and sampling as per Table 3.

flowchart LR
  A[Corrugated Sheet] --> B[Measure Thickness (avg of 6)]
  A --> C[Measure Depth (6 corrugations)]
  A --> D[Measure Pitch (over 6 pitches)]
  B --> E{Within ±10%?}
  C --> F{Within +2/-0 mm?}
  D --> G{Within ±2 mm?}
  E --> H[Accept or Reject]
  F --> H
  G --> H

This ensures dimensional conformity for quality and fit.

IS 15476 - Finish and Appearance: Key Specifications & Tests

1. Dimensional Tolerances (Table 1, Clause 6.1.1)

• Thickness measured as average of 6 points (excluding valleys).
• Depth measured with depth gauge on 6 corrugations.
• Pitch tolerance applies over 6 pitches total length.

2. Finish Inspection (Clause 9.1.2)

• All sheets inspected for finish as per Clause 7.
• Defective sheets removed from lot.

3. Water Impermeability Test (Clause 1.20 & Annex D)

• Whole sheet (≥1.2 m) sealed in frame, water filled 20 mm above corrugations.
• Conditioned at 27 ± 2°C, 65 ± 5% RH for 24 h.
• Pass: No water drops on lower surface; traces of moisture allowed.

4. Water Absorption Test (Annex E, Table 2(iv))

• Specimens 300x300 mm preconditioned at 27 ± 2°C, 65 ± 5% RH.
• Submerged 24 h in 25 mm water at 27 ± 2°C.
• Water absorption ≤ 15% by mass increase.

5. Cyclic Test (Table 2(v))

• Specimens 150x150 mm.
• 3 cycles: 4 h boiling + 16 h drying at 65 ± 2°C.
• No delamination allowed.

6. Falling Weight Test (Table 2(vi))

• Whole sheet ≥1.2 m.
• No break, crack, or tear after test.

7. **Other Requirements (Table

IS 15476 - Key Requirements for Bitumen Macadam Coated Sheets (BMCS)

Table 2: BMCS Requirements (Clause 8.1)

Notes:

• Lot conformity: Number of defectives ≤ acceptance number (Table 3) → Lot accepted.
• Sampling: As per Clause 9.1.3, random sampling size defined in Table 3.

Summary of Key Specifications:

• Density: Minimum 0.75 g/cm³ ensures material compactness.
• Load Capacity: Ensures mechanical strength under dry/wet conditions.
• Impermeability & Water Absorption: Critical for durability against moisture.
• Fire Resistance: Minimum flame penetration and burning rates ensure safety.

flowchart TD
    A[BMCS Sheet] --> B{Tests}
    B --> C[Density ≥ 0.75 g/cm³]
    B --> D[Load Capacity Dry ≥ 4.0 N/mm]
    B --> E[Load Capacity Wet ≥ 3.0 N/mm]
    B --> F[Impermeability: No water drops]
    B --> G[Water Absorption ≤ 15%]
    B --> H[No Delamination]
    B --> I[No Break/Crack on Falling Weight]
    B --> J[Fire Resistance: Flame ≥ 10 min]
    B --> K

IS 15476: Sampling and Test Methods - Key Points

Sampling (Clause 9.1.3, 9.2.1, 9.2.2)

• Dimensional requirements are checked first.
• If conforming, other tests are performed on the sample size per column 5.

Test Method for Density (Table 2, SI No. (i))

• Take 3 specimens of size 300 mm × 300 mm.
• Condition at 65 ± 5% RH and 27 ± 2°C until constant mass.
• Weigh to ±1 g accuracy.
• Measure thickness as average of 6 random readings (excluding valleys).

Additional References (Annex A)

• IS 4905: Method of random sampling.
• IS 6874: Methods for tests for round bamboos.
• IS 401: Preservation of timber - Code of practice.

flowchart TD
    A[Lot Received] --> B{Lot Size?}
    B --> |Up to 500| C[Sample 20 sheets]
    B --> |501 to 1000| D[Sample 32 sheets]
    B --> |1001 to 3000| E[Sample 50 sheets]
    B --> |Above 3000| F[Sample 80 sheets]
    C --> G[Check Dimensional Req.]
    D --> G
    E --> G
    F --> G
    G --> |Pass| H[Sample for Other Tests (per Table)]
    G --> |Fail| I[Reject Lot]

Summary: Use Table 3 for sample sizes and acceptance numbers; test

IS 15476: Marking and Packaging Key Points

1. Marking (Clause 10.1 & 10.2)

• Location: Marking shall be on the face of the sheet near one edge.
• Standard Mark: Bamboo mat corrugated sheets may carry the BIS Certification Mark.

2. Sample Size & Acceptance (Clause 9.2.1)

3. Dimensions & Tolerances (Clause 6.1.1)

• Thickness is average of 6 random measurements (excluding valleys).
• Depth measured with depth gauge; max deviation per Table 1.
• Pitch tolerance measured over six pitches.

4. Packaging

• Not explicitly detailed in context; typically, sheets should be stacked flat and protected from moisture and mechanical damage during transport.

Summary Diagram: Marking & Sampling Process

flowchart TD
    A[Lot Size] --> B{Check Lot Size}
    B -->|Up to 500| C[Sample Size = 20

IS 15476: Additional Requirements for Eco-Mark on Bamboo Mat Corrugated Sheets (BMCS)

Key Specifications:

• Eco-Mark Eligibility:

  • BMCS must conform to all relevant clauses of IS 15476 and specific Eco-Mark criteria.
  • Only bamboo sourced outside natural forests is permitted for Eco-Mark products (Clause 4.1).
  • Manufacturer must provide documentary evidence (certificate/declaration) to BIS for Eco-Mark application (Clause 10.2).

• Environmental Clearances:

  • Manufacturer must produce environmental consent clearance from State Pollution Control Board under:
    • Water (Prevention and Control of Pollution) Act, 1974 & 1977
    • Air (Prevention and Control of Pollution) Act, 1981
    • Environment (Protection) Act, 1986 (Clause 10.1.2)
  • Compliance with forest department rules is mandatory.

• Marking:

  • Eco-Mark includes a combined ISI Mark + Eco logo (Amendment No. 2).

• Preservative Treatment:

  • Finished sheets must be coated with light organic solvent preservative (LOSP) like zinc or copper naphthenate to prevent fungus (Clause 7.2).

Summary Table for Eco-Mark Compliance

flowchart TD
    A[Start Manufacturing] --> B{Bamboo Source}
    B -- Outside Natural Forest --> C[Apply LOSP Coating]
    B -- Natural Forest Source --> D[Not Eligible for Eco-Mark]
    C --> E[Obtain Environmental Clearance]
    E --> F[Submit Certificate to BIS]
    F --> G{Compliance Confirmed?}
    G -- Yes --> H[Get Eco-Mark + ISI Mark]
    G

IS 15476: List of Referenced Indian Standards (Annex A)

This standard on Bamboo Mat Corrugated Sheets (BMCS) references key Indian Standards essential for manufacture, testing, and quality assurance:

Key Specifications for BMCS Testing (from IS 15476)

• Density Calculation Method:

  • Take 3 specimens of 300 mm x 300 mm, precondition at 65 ± 5% RH and 27 ± 2°C.
  • Weigh specimens to ±1 g accuracy.
  • Measure thickness at 6 random points (excluding valleys).
  • Density = Mass / Volume (Volume = area × average thickness).

• Sample Size & Acceptance Criteria (Table 3):

Notes:

• Final test values should be rounded as per IS 2:1960.
• BMCS are eco-friendly, water-resistant, decay-resistant, and fire-retardant roofing sheets.

flowchart TD
    A[Specimen Preparation] --> B[Condition at 65±5% RH, 27±2°C]
    B --> C[Weigh Specimen (±1g)]
    C --> D[Measure Thickness (6 points)]
    D --> E[Calculate Density = Mass

Density Test Method as per IS 15476

Specimen Preparation:

• Take 3 specimens of size 300 mm × 300 mm.
• Precondition at 65 ± 5% RH and 27 ± 2°C until constant mass.

Measurement:

• Weigh each specimen to ±1 g accuracy.
• Measure dimensions:
  • Thickness: average of 6 random readings (exclude valley portions).
  • Length & Width: average of 6 random readings.
  • For sinusoidal corrugation, multiply width by 1.376.

Density Calculation:

[ \text{Density} = \frac{\text{Mass (g)}}{\text{Volume (cm}^3\text{)}} ]

Where,

[ \text{Volume} = \text{Length} \times \text{Width (corrected)} \times \text{Thickness} ]

Requirements:

• Minimum Density = 0.75 g/cm³ (Table 2, Clause 8.1)

Sampling & Acceptance (Table 3)

Summary Flowchart

flowchart TD
    A[Take 3 specimens 300x300 mm] --> B[Condition at 65±5% RH, 27±2°C]
    B --> C[Weigh specimens (±1g)]
    C --> D[Measure thickness (6 readings avg)]
    D --> E[Measure length & width (6 readings avg)]
    E --> F[Correct width (×1.376 for sinusoidal)]
    F --> G[Calculate Density = Mass / (L×W×T)]
    G --> H{Density ≥ 0.75 g/cm³?}
    H -- Yes --> I[Specimen passes density test]
    H --

IS 15476: Load Bearing Capacity Test for BMCS (Bitumen Macadam Corrugated Sheets)

Key Specifications & Procedure:

• Specimen Preparation:

  • Full sheet cut into two halves across width.
  • One half tested dry, other after 24h soaking (wet).
  • Average length & width from 6 random readings.
  • Actual width = measured width × 1.376 (for sinusoidal corrugation).

• Test Setup:

  • Specimen supported on two parallel rigid bearers (50 mm wide) spaced 1 m center-to-center.
  • Bearers perpendicular to corrugations.
  • Load applied at mid-span via a self-aligning flat beam (230 ± 5 mm wide).
  • Alternative: Universal Testing Machine (UTM) with roller supports.
  • Load increments: 20 kg at uniform rate ≤ 2000 N/min.

• Load Bearing Capacity Calculation: [ \text{Load Bearing Capacity (N/mm)} = \frac{\text{Load at failure (N)}}{\text{Width of specimen (mm)}} ]

• Acceptance Criteria (Table 2, Clause 8.1):

• Reporting:
  • Record breaking load.
  • Compute load bearing capacity as above.

Summary Table: Load Bearing Capacity Test Setup

flowchart LR
    A[Cut Sheet into 2 halves] --> B[Half 1: Dry Test]
    A --> C[Half 2: Soak 24h → Wet Test]
    B & C --> D[Place on 2 Bearers (50mm wide, 1m apart)]
    D --> E[Load at mid-span via flat beam

IS 15476: Impermeability Test for BMCS (Bitumen Macadam Corrugated Sheets)

Key Specifications & Procedure (Clause 1.20, Annex D)

• Specimen: Whole sheet, minimum length 1.20 m, conditioned for 5 days at 27 ± 2°C and 65 ± 5% RH.
• Test Setup:
  • A frame (Fig. 3) sealed on the sheet surface.
  • Water filled to 20 mm above corrugation peaks inside the frame.
• Environment: Keep assembly at 27 ± 2°C and 65 ± 5% RH for 24 hours.
• Acceptance Criteria:
  • No water droplets on the lower surface after 24 h.
  • Traces of moisture are permissible but no dripping.

Reporting Results (Annex D-3)

Related Key Tests & Limits (Table 2, Clause 8.1)

Summary Diagram of Impermeability Test Setup

flowchart LR
    A[Whole Sheet Specimen] --> B[Seal Frame on Sheet]
    B --> C[Fill water 20 mm above corrugations]
    C --> D[Keep at 27 ± 2°C, 65 ± 5% RH for 24 h]
    D --> E[Examine underside for water droplets]
    E -->|No drops| F[Pass]
    E -->|Drops present| G[Fail]

This test ensures the sheet's