Method of identification of natural building stones

IS 1123 - Scope & Key Specifications Summary

Scope (Clause 3.2):

• Identification of building stones based on physical and engineering properties.
• Classification of stones into Igneous, Sedimentary, and Metamorphic types.
• Use of Table 1 for characteristics and engineering properties.

Key Table: Characteristics of Building Stones (Excerpt from Table 1)

Important Notes:

• Stones should be free from flaws, joints, and fractures for structural use.
• Engineering properties like compressive strength, tensile strength, porosity, and modulus of elasticity guide suitability.
• Use Table 1 for selecting stones based on project requirements.

flowchart LR
    A[Identify Rock Type] --> B{Rock Class}
    B -->|Igneous| C[Granite / Basalt / Syenite]
    B -->|Sedimentary| D[Sandstone / Limestone]
    B -->|Metamorphic| E[Schist / Quartzite]
    C --> F[Check Engineering Properties]
    D --> F
    E --> F
    F --> G[Select Stone Based on Use & Strength]

For detailed engineering design, refer to IS 1123 Table 1 and follow guidelines on reporting and sample identification (Clause 4.1).

IS 1123: Selection of Sample for Natural Building Stones

Key Specifications:

• Sample Source: Fresh, unweathered rock from quarry ledge or natural outcrop.
• Sample Size: Minimum 25 kg per distinct stratum.
• Sampling Method:
  • Inspect quarry face for variations in color, texture, structure.
  • Collect separate samples from each visually different stratum.
  • Exclude damaged pieces (blasting, wedges, heating).

Summary Table:

Notes:

• Adequate size ensures enough material for all required tests.
• Sampling must represent all visible variations to ensure stone grade consistency.

flowchart TD
    A[Inspect Quarry Face] --> B{Variations?}
    B -- Yes --> C[Collect ≥ 25 kg Sample per Variation]
    B -- No --> D[Collect ≥ 25 kg Sample]
    C & D --> E[Exclude Damaged Stones]
    E --> F[Prepare Test Pieces]

This ensures representative sampling for reliable stone identification and testing.

IS 1123: Identification of Natural Building Stones - Key Points

1. Reporting (Clause 4.1)

• Report date of sample taken, identification of sample, and type of stone.

2. Characteristics of Building Stones (Table 1, Clause 3.2)

3. Common Stone Types & Uses

• Granite: High strength, used for bridges, dams, monuments.
• Basalt: Dense, used for heavy structures, pavements.
• Sandstone: Used in masonry, dams, ornamental stone.
• Syenite, Trachyte, Andesite: Used as dimension stones or aggregates.

4. Identification Procedure (Summary)

• Examine colour, texture, mineral composition.
• Test physical properties: specific gravity, strength, porosity.
• Check for flaws, joints, fractures affecting usability.

Example: Granite Properties Snapshot

IS 1123 - Reporting on Building Stones: Key Points

Reporting Requirements (Clause 4.1)

• Report must include:
  • Date of sample collection
  • Sample identification
  • Type of stone (refer Table 1 for classification)

Table 1: Characteristics & Engineering Properties of Building Stones (Clause 3.2)

Usage & Availability Notes

• Granites and basalts are preferred for heavy structures like dams, bridges.
• Sedimentary stones like sandstone are used for masonry and ornamental works.
• Metamorphic stones like slate are used for roofing and tiles.

Summary Diagram: Reporting Flow

flowchart TD
    A[Sample Collection] --> B[Record Date & ID]
    B --> C[Identify Stone Type]
    C --> D[Refer Table 1 for Properties]
    D --> E[Report Preparation]
    E --> F[Submission to BIS/Client]

Note: Use Table 1 from IS 1123 for detailed stone classification and engineering properties during reporting. Always specify sample details and stone type for clarity and traceability.

IS 1123: Characteristics of Building Stones – Key Data

Typical Stone Types & Uses:

• Granite: Light to pink, quartz/feldspar; high strength; used for bridges, monuments, pavements.
• Basalt (Deccan Trap): Dark grey/black, medium grain; used for heavy structures, road metal.
• Sandstone: Stratified, quartz-rich; masonry, dams, ornamental stone.
• Slate: Fine-grained, fissile; roofing, tiles.
• Khondalite & Schists: Used in blocks/slabs, but may weather easily.

Notes:

• Stones must be free from flaws, joints, and fractures for structural use.
• Porosity and abrasion resistance directly affect durability.
• Identification includes color, texture, mineralogy, and engineering properties.

flowchart LR
    A[Building Stones] --> B[Physical Properties]
    B --> C[Specific Gravity]
    B --> D[Strength (Compressive, Tensile, Shear)]
    B --> E[Porosity & Abrasion Resistance]
    B --> F[Modulus of Elasticity]
    A --> G[Uses]
    G --> H[Structural (Bridges, Dams)]
    G --> I[Decorative (Monuments, Tiles)]

Reference: IS 1123 Table 1, Clause 3.2 for detailed stone characteristics

Classification of Stones as per IS 1123

IS 1123 classifies natural building stones mainly by rock type, physical properties, and engineering characteristics.

Key Rock Classes & Properties (from Table 1, Clause 3.2)

IS 1123: Physical & Engineering Properties of Building Stones

Key Specifications (from Table 1, Clause 3.2):

Common Rock Types & Uses:

• Granite: High strength (2×10⁵ to 6×10⁵ kg/cm²), used for heavy structures, pavements, monuments.
• Basalt: Medium to high strength (1500-3000 kg/cm²), suitable for bridge piers, river walls.
• Sandstone: Moderate strength (200-1700 kg/cm²), used in masonry, dams.
• Slate: Low to medium strength (1000-2000 kg/cm²), used for roofing, tiles.

Notes:

• Strength and other properties depend on mineral composition and texture.
• Porosity affects durability; lower porosity means better resistance to weathering.
• Joints and fractures reduce effective strength and usability.

Formula for Modulus of Elasticity (E):

[ E = \frac{\sigma}{\epsilon} ] Where:

• ( \sigma ) = stress (kg/cm²)
• ( \epsilon ) = strain (dimensionless)

Summary Diagram (Rock Properties & Uses)

graph TD
    A[Building Stones] --> B[Igneous Rocks]
    A --> C[Sedimentary Rocks]
    B --> D[Granite]
    B --> E[Basalt]
    C --> F[Sandstone]
    C --> G[

Use of Stones - Key Specifications from IS 1123

Sampling & Inspection (Clauses 2.2.1 & 2.2.2)

• Samples: Minimum 25 kg from each stratum differing in colour, texture, structure.
• Inspection: Check quarry face or field stones for variations, joints, fractures, and flaws.
• Reject: Stones damaged by blasting, heating, or with cracks and joints unsuitable for homogeneous blocks.

Physical & Engineering Properties (Table 1 Highlights)

Important Notes

• Stones must be free from flaws, cracks, joints to ensure durability.
• Porosity affects durability; lower porosity preferred for

Inspection of Quarry and Field Stones (IS 1123)

Key Clauses:

• Clause 2.2.1 (Quarry Stones):

  • Inspect quarry face for strata variation (color, texture, structure).
  • Collect ≥ 25 kg samples from each distinct stratum.
  • Exclude damaged pieces (blasting, wedges, heating).

• Clause 2.2.2 (Field Stones and Boulders):

  • Conduct detailed inspection over supply area.
  • Record types and conditions of stones.
  • Select separate samples for each class based on visual inspection.

• Clause 4.1 (Reporting):

  • Report date, sample ID, and stone type.

Important Table Extract: Characteristics of Building Stones (Clause 3.2)

Summary of Inspection Procedure:

1. Visual Inspection:

   • Identify strata variations.
   • Note color, texture, and structural differences.

2. Sampling:

   • Quarry: ≥ 25 kg samples per stratum.
   • Field: Separate samples for each stone class.

3. Exclusion Criteria:

   • Avoid damaged/deteriorated stones.

4. Reporting:

   • Document sample details (date

IS 1123: Key Annexures, Tables & Specifications Summary

1. Table 1: Characteristics of Building Stones (Clause 3.2)

2. Stone Types & Uses

• Granite: High strength, used in bridges, dams, monuments.
• Basalt (Deccan Trap): Dense, good for heavy structures.
• Sandstone: Used in masonry, dams, ornamental stone.
• Trachyte & Andesite: Dimension stones, decorative use.

3. Reporting Requirements (Clause 4.1)

• Date of sample taken
• Sample identification
• Type of stone

4. Identification Approach

• Petrographical examination
• Mineralogical composition
• Texture & structure

Example: Compressive Strength Classification of Granite

Summary Diagram: Stone Identification Process

flowchart TD
    A[Sample Collection] --> B[Physical Examination]
    B --> C[Petrographical Analysis]
    C --> D[Mineralogical Composition]
    D --> E[Classification & Reporting]

Note: Values are indicative; always refer to latest IS 1123 edition for precise data.