laterite stone block for masonry

IS 3620: Scope - Key Specifications & Tables

1. Dimensions & Tolerances (Clause 3.1 & 3.3):
Standard laterite stone block sizes (mm):

• Tolerance: +5 mm allowed on these dimensions.

2. Physical Properties & Testing (Clause 7.4):

• Sampling as per Table 3 (sub-sample size).
• Tests: Compressive strength, water absorption, specific gravity.
• Lot acceptance: No failures in tested blocks.

3. Rounding Off (Clause 0.4):

• Final test/analysis values rounded per IS 2-1960.
• Retain significant figures same as specified values.

Summary:

• Use Table 1 for block sizes with +5 mm tolerance.
• Test physical properties on random samples per clause 7.4.
• Round off results as per IS 2.

flowchart TD
    A[Laterite Stone Blocks] --> B[Dimensions per Table 1]
    B --> C{Tolerance +5 mm}
    A --> D[Sampling per Table 3]
    D --> E[Tests: Compressive Strength, Water Absorption, Specific Gravity]
    E --> F{All tests passed?}
    F -->|Yes| G[Lot Accepted]
    F -->|No| H[Lot Rejected]

IS 3620: General Requirements - Key Formulas, Tables & Specifications

1. Tolerance on Dimensions (Clause 3.3)

• Tolerance: +5 mm allowed on dimensions specified in Table 1.

2. Physical Properties (Clause 4.1 & Table 2)

3. Sampling & Conformity (Clause 7.3 & 7.4, Table 3)

• Sampling: Random sub-sample size as per Table 3.
• Tests: Compressive strength → Water absorption → Specific gravity.
• Acceptance: Lot passes if no block fails any test.
• Defective Blocks: Permissible defectives limit as per Table 3.

Summary Diagram of Testing Flow

flowchart TD
    A[Select Lot] --> B[Random Sampling (Table 3)]
    B --> C[Examine General Requirements]
    C --> D{Defectives ≤ Permissible?}
    D -- Yes --> E[Test Compressive Strength]
    E --> F[Test Water Absorption]
    F --> G[Test Specific Gravity]
    G --> H{Any Failures?}
    H -- No --> I[Lot Accepted]
    D -- No --> J[Lot Rejected]
    H -- Yes --> J

Note: Refer to Table 1 for dimensions and Table 3 for sampling details as per IS 3620.

IS 3620: Dimensions and Tolerances for Laterite Stone Blocks

Key Specifications:

• Standard Sizes (Table 1):

• Tolerance:

  • A tolerance of +5 mm is permitted on all dimensions specified in Table 1 (Clause 3.3).

• Custom Sizes:

  • Sizes other than those in Table 1 may be supplied if mutually agreed (Clause 3.2).

• Stabilization:

  • Blocks should be exposed for 3 months before use to ensure stabilization, avoiding rain exposure (Clause 2.2).

Summary:

• Use standard sizes with +5 mm tolerance.
• Custom sizes allowed by agreement.
• Proper curing/stabilization critical for durability.

flowchart TD
    A[Laterite Stone Blocks] --> B[Standard Sizes (Table 1)]
    B --> C{Tolerance +5 mm}
    A --> D[Custom Sizes]
    D --> E[Agreement between purchaser & supplier]
    A --> F[Stabilization]
    F --> G[3 months exposure]
    F --> H[Protect from rain]

IS 3620: Physical Properties of Laterite Stone Blocks

Key Notes:

• Dimensional tolerance: +5 mm allowed (Clause 3.3).
• Sampling for physical tests should be random and per Clause 7.4.
• A lot passes if no block fails in compressive strength, water absorption, or specific gravity tests.
• Final test values must be rounded per IS:2-1960 rules.

Summary Table (Physical Properties):

| Property            | Min/Max Value | Unit     | Test Standard          |
|---------------------|---------------|----------|-----------------------|
| Water Absorption    | ≤ 12          | % mass   | IS 1124-1974          |
| Specific Gravity    | ≥ 2.5         | -        | IS 1124-1974          |
| Compressive Strength| ≥ 3.5         | N/mm²    | IS 1121 (Part I)-1974 |

This ensures durability and suitability of laterite blocks for construction as per IS 3620.

IS 3620: Workmanship - Key Specifications & Sampling

• Inspection criteria (Clause 7.3):
  Blocks selected per Table 3 are checked for:

  • General requirements (Clause 2)
  • Dimensions (Clause 3) with ±5 mm tolerance (Clause 3.3)
  • Workmanship (Clause 5)
    Any defective block = block rejected.

• Sampling & Conformity (Table 3, Clause 7.2):

• Physical Properties Testing (Clause 7.4):
  Sub-sample tested for compressive strength, water absorption, and specific gravity.
  Lot passes if none fail.

Summary:
Workmanship acceptance is based on zero or minimal defectives per sample size, with dimensional tolerance ±5 mm. Sampling follows Table 3, ensuring quality control before physical testing.

flowchart TD
    A[Select blocks as per Table 3] --> B{Check: General, Dimensions, Workmanship}
    B -- Pass --> C[Sample sub-sample for physical tests]
    B -- Fail --> D[Reject block/lot if defectives > permissible]
    C --> E[Test compressive strength, water absorption, specific gravity]
    E -- All pass --> F[Lot accepted]
    E -- Any fail --> D

IS 3620: Marking Key Points

• Clause 6.1: Blocks must be marked with the manufacturer's identification mark or initials in a suitable manner for traceability.

• Clause 3.3: A tolerance of +5 mm is allowed on dimensions specified in Table 1 (dimensional accuracy).

• Sampling & Testing (Clause 7.4):

  • Random sub-samples are taken from the lot for testing physical properties:
    • Compressive strength
    • Water absorption
    • Specific gravity
  • Lot passes if none of the tested blocks fail these tests.

Summary Table for Marking & Tolerances

Conceptual Flow for Marking & Quality Control

flowchart TD
    A[Manufacturing] --> B[Marking with Manufacturer's ID]
    B --> C[Dimension Check (+5 mm tolerance)]
    C --> D[Sampling as per Table 3]
    D --> E[Physical Tests: Strength, Absorption, Gravity]
    E --> F{Any Failures?}
    F -- No --> G[Lot Accepted]
    F -- Yes --> H[Lot Rejected]

Note: For detailed sampling sizes and dimension tables, refer to IS 3620 Table 1 and Table 3.

IS 3620: Sampling and Criteria of Conformity

Sampling Procedure (Clause 7.2)

• Sample size depends on lot size as per Table 3 below.
• Manufacturer's blocks are marked for identification (Clause 6.1).
• Samples tested separately for each lot (Clause 7.1.1).

Criteria of Conformity (Clause 7.4)

• After general requirements, dimension, and workmanship pass, test sub-sample for:
  • Compressive strength
  • Water absorption
  • Specific gravity
• Lot is accepted only if none of the sub-sample blocks fail any test.

Summary Flowchart (Sampling & Testing)

flowchart TD
    A[Start: Lot of Blocks] --> B[Mark blocks with ID]
    B --> C[Select sample size as per Table 3]
    C --> D[Test for general requirements, dimension, workmanship]
    D -->|Pass| E[Select sub-sample for physical tests]
    D -->|Fail| F[Reject Lot]
    E --> G[Test compressive strength, water absorption, specific gravity]
    G -->|All pass| H[Accept Lot]
    G -->|Any fail| F[Reject Lot]

Note: Ensure random sampling for unbiased results. Use sub-sample size from Table 3 for physical property tests.