Method of test for abrasion resistance of concrete

IS 9284: Key Formulas, Tables & Specifications (Introduction & Abrasion Loss)

Abrasion Loss Reporting (Clause 8.1)

• Abrasion loss of concrete is averaged over 12 surfaces (4 surfaces each of 3 cubes).
• Reported to the nearest 0.01 g.
• Expressed as percent loss.

Tentative Maximum Abrasion Loss Values (Appendix A)

Notes:

• These values are tentative and for broad guidance only.
• Abrasion loss is a critical durability measure for concrete surfaces exposed to traffic or wear.

Summary Formula for Abrasion Loss (%):

[ \text{Abrasion Loss (%)} = \frac{\text{Weight loss (g)}}{\text{Initial weight (g)}} \times 100 ]

flowchart LR
    A[Concrete Cubes] --> B[3 Cubes]
    B --> C[4 Surfaces Each]
    C --> D[12 Surfaces Total]
    D --> E[Abrasion Test]
    E --> F[Weight Loss Measured]
    F --> G[Calculate % Loss]
    G --> H[Report Average Abrasion Loss]

This ensures uniformity and reliability in abrasion loss measurement as per IS 9284.

IS 9284: Scope & Key Specifications on Abrasion Loss of Concrete

Scope (Clause 8.1)

• Abrasion loss is reported as the average percent loss from 12 surfaces (4 surfaces each of 3 cubes).
• Measurement precision: nearest 0.01 g.

Tentative Maximum Abrasion Loss Values (Appendix A-1)

Abrasive Charge (Clause 3.3)

• Sand conforming to IS 650-1966, graded to pass 1.00 mm sieve and retained on 0.50 mm sieve.
• Reusable after sieving through 0.50 mm.

Nozzle & Air Pressure (Clause 3.2.2)

• Air pressure: 0.14 N/mm² (approx. 1.4 bar).
• Nozzle assembly fixed with lock nut; hopper cone angle ensures sand flow.

Summary Formula for Abrasion Loss (%):

[ \text{Abrasion Loss} = \frac{\text{Weight loss (g)}}{\text{Original weight (g)}} \times 100 ]

flowchart LR
    A[Concrete Cubes (3)] --> B[4 Surfaces each]
    B --> C[12 Surfaces Total]
    C --> D[Measure Weight Loss (g)]
    D --> E[Calculate % Abrasion Loss]
    E --> F[Report Average Abrasion Loss ±0.01g]

This ensures standardized abrasion resistance evaluation per IS 9284.

Working Principle (IS 9284)

• The test abrades concrete cubes by impinging air-driven silica sand on their surface.
• A conical galvanized iron hopper holds the sand charge; its cone angle ensures sand flows down naturally.
• Sand is fed through a nozzle passing from the hopper bottom through the cabinet top.
• Air pressure of 0.14 N/mm² (approx. 1.4 bar) drives the sand; pressure is monitored near the nozzle by a gauge.
• The sand used is graded per IS 650:1966, passing 1.00 mm and retained on 0.50 mm sieve.
• The apparatus dimensioning (nozzle, hopper, cabinet) ensures consistent sand flow and impingement (see Fig. 2 in IS 9284).

Key Specifications Summary

Sand Abrasion Setup (Simplified Flow)

flowchart TD
    A[Compressor] -->|Air @ 0.14 N/mm²| B[Pressure Gauge]
    B --> C[Air Tube]
    C --> D[Nozzle through Hopper]
    D --> E[Sand from Hopper]
    E --> F[Concrete Cube Surface]

This setup ensures controlled sand impingement to evaluate abrasion resistance of concrete cubes.

IS 9284: Apparatus Specifications & Key Details

1. Conical Galvanized Iron Hopper (Clause 3.2.2)

• Holds sand charge driven by air pressure.
• Nozzle passes through hopper bottom and cabinet top; nozzle is threaded at cabinet top.
• Lock nut & washer fix nozzle assembly.
• Air pressure gauge fitted near nozzle on copper/brass tube.
• Air supply pressure: 0.14 N/mm² (approx. 1.4 bar).
• Hopper cone angle ensures sand flows down naturally.
• Nozzle dimensions per Fig. 2 (all dimensions in mm).

2. Specimen Carrier and Cradle (Clause 3.2.3)

• Cradle moves 17 cm between two fixed points.
• Carrier and cradle angled 10° to horizontal.
• Nozzle tip kept 2.5 cm from specimen edge (10 cm cube).
• Allows two impingements per surface by rotating specimen 180°.

3. Abrasive Charge (Clause 3.3)

• Sand per IS 650-1966, graded to:
  • Pass 1.00 mm IS sieve
  • Retained on 0.50 mm IS sieve
• Reusable after sieving through 0.50 mm.

4. Table: Suggested Maximum Abrasion Loss (Appendix A)

Summary Diagram of Apparatus Setup

flowchart TB
    A[Compressor] -->|Air at 0.14 N/mm²| B[Pressure Gauge]
    B --> C[Copper/Brass Air Tube]
    C --> D[Nozzle Assembly]
    D --> E[Conical Hopper with Sand]
    E --> F[Specimen Carrier on Cradle]
    F --> G[Concrete Specimen (10 cm cube)]
    style D fill:#f9f,

IS 9284: Operating Conditions for Abrasion Test on Concrete

Key Operating Conditions (Clause 4.1)

• Air Pressure: 0.14 N/mm² (1.4 bar)
• Abrasive Charge: Sand as per IS 650-1966, graded to pass 1.00 mm sieve and retained on 0.50 mm sieve (Clause 3.3)
• Quantity of Charge: 4000 g per impingement
• Abrasion Loss Measurement: Mass loss (grams) after two impressions on the same concrete cube face

Abrasive Charge Specification (Clause 3.3)

• Sand must conform to IS 650-1966
• Particle size between 0.5 mm and 1.0 mm
• Reusable after sieving through 0.5 mm sieve

Apparatus Setup (Clause 3.2.2)

• Conical galvanized iron hopper with sand inlet holes at bottom
• Nozzle fixed through hopper and cabinet top with lock nut and washer
• Pressure gauge near nozzle to maintain 0.14 N/mm² air pressure
• Hopper cone angle ensures sand flows freely

Summary Table: Operating Parameters

flowchart TD
    A[Sand Hopper] --> B[Nozzle]
    B --> C[Concrete Specimen Surface]
    D[Compressor] --> E[Air Tube with Pressure Gauge]
    E --> B
    style B fill:#f9f,stroke:#333,stroke-width:2px
    style C fill:#bbf,stroke:#333,stroke-width:2px

This setup ensures consistent abrasion testing under controlled air pressure and sand charge conditions per IS 9284.

IS 9284: Preparation of Concrete Specimens for Abrasion Test

Key Specifications (Clauses 3.2.3, 4.1, 5.1, 6.1)

• Specimen size: 10 cm cube, cured for 28 days or as received.
• Pre-test conditioning: Oven dry at 50°C for 24 hours; surface rubbed with emery paper to expose aggregates.
• Specimen carrier setup:
  • Mounted on cradle movable between two fixed points 17 cm apart.
  • Carrier & cradle inclined at 10° to horizontal, presenting specimen face at 10° to vertical.
  • Nozzle tip positioned 2.5 cm from specimen edge (midpoint of half side).
• Operating conditions:
  • Air pressure: 0.14 N/mm²
  • Abrasive charge: 4,000 g sand per impingement
  • Two impingements per surface by rotating specimen 180°.
• Measurement: Abrasion loss = mass loss (g) after two impressions on same surface.

Test Procedure Summary

flowchart LR
    A[Prepare 10 cm cube specimen] --> B[Oven dry at 50°C for 24 hrs]
    B --> C[Rub surface with emery paper]
    C --> D[Weigh specimen]
    D --> E[Place on carrier (10° incline)]
    E --> F[Position nozzle 2.5 cm from edge]
    F --> G[Blast with 4000 g abrasive sand at 0.14 N/mm²]
    G --> H[Move cradle 17 cm slowly during blast]
    H --> I[Rotate specimen 180°]
    I --> J[Repeat blast]
    J --> K[Clean & weigh specimen]
    K --> L[Calculate mass loss (abrasion loss)]

Formula for Abrasion Loss

[ \text{Abrasion Loss (g)} = W_{\text{before}} - W_{\text{after}} ]

• (W_{\text{before}}) = specimen mass before test
• (W_{\text{after}}) = specimen mass after two sand impingements

This ensures standardized abrasion resistance evaluation of concrete per IS 9284.

IS 9284: Test Procedure for Abrasion Resistance of Concrete

Key Steps (Clause 6.1)

• Use a weighed, dry concrete cube specimen.
• Place on specimen carrier with one smooth vertical surface facing the nozzle tip.
• Nozzle tip positioned 2.5 cm from the edge, at the middle of half the cube side.
• Expose surface to sand blast with 4,000 g sand charge.
• Move the cradle slowly between two fixed points during blasting.
• Rotate specimen 180° horizontally and repeat blast on the same surface (two impressions total).
• After testing, clean and weigh specimen to determine mass loss (abrasion loss in grams).

Additional Notes

• Applicable also to stone and cement mortar surfaces (Clause 3.1).
• Results should be rounded as per IS 2-1960 rules.
• Mass loss quantifies abrasion resistance: lower loss = higher resistance.

Summary Table

flowchart LR
    A[Weighed Dry Specimen] --> B[Place on Carrier]
    B --> C[Nozzle at 2.5 cm from edge]
    C --> D[Sand blast with 4000 g sand]
    D --> E[Move cradle slowly]
    E --> F[Rotate specimen 180°]
    F --> D
    D --> G[Clean & weigh specimen]
    G --> H[Calculate mass loss]

This procedure ensures standardized abrasion resistance measurement for concrete surfaces.

IS 9284: Calculation and Expression of Results

1. Loss in Mass Calculation (Clause 7.1)

[ m = m_1 - m_2 ]

• ( m ) = loss in mass (g)
• ( m_1 ) = mass before test (g)
• ( m_2 ) = mass after test (g) (on one surface with two impressions)

2. Reporting Abrasion Loss (Clause 8.1)

• Average abrasion loss is calculated over 12 surfaces (4 surfaces each of 3 cubes).
• Reported to the nearest 0.01 g.
• Expressed as percent loss.

3. Tentative Maximum Abrasion Loss Values (Appendix A)

Summary Diagram: Abrasion Loss Calculation Flow

flowchart TD
    A[Specimen Mass Before Test (m1)] --> B[Conduct Abrasion Test]
    B --> C[Specimen Mass After Test (m2)]
    C --> D[Calculate Loss: m = m1 - m2]
    D --> E[Repeat for 12 surfaces]
    E --> F[Calculate Average Loss]
    F --> G[Express as % Loss and Report]

Note: Round numerical values as per Clause 3.2.1 rules.

IS 9284 - Abrasion Loss Reporting and Tentative Limits

Key Formula for Abrasion Loss (Clause 8.1)

• Abrasion Loss (%) =
  [ \frac{\text{Average weight loss of 12 surfaces (4 surfaces × 3 cubes)}}{\text{Original weight}} \times 100 ]
• Report average abrasion loss to nearest 0.01 g and express as % loss.

Tentative Maximum Values of Abrasion Loss (Appendix A, Table A-1)

Summary:

• Test 12 surfaces (4 per cube × 3 cubes).
• Express abrasion loss as % weight loss.
• Use the above limits for assessing concrete surfacing durability.

flowchart TD
    A[Test 3 cubes] --> B[Measure 4 surfaces each]
    B --> C[Calculate weight loss per surface]
    C --> D[Average weight loss of 12 surfaces]
    D --> E[Convert to % abrasion loss]
    E --> F[Compare with max permissible values]

This ensures consistent evaluation of abrasion resistance per IS 9284.

IS 9284: Tentative Suggested Values of Abrasion Loss

This standard evaluates abrasion resistance of concrete surfaces by measuring mass loss after abrasive charge impingement on concrete cubes (density 24-26 kN/m³).

Key Points:

• Abrasion loss = mass loss of specimen after test.
• Applies to normal weight concrete, stone, and cement mortar surfaces.
• Test simulates abrasion on pavements, industrial floors, platforms, dockyards, footpaths.

Tentative Permissible Abrasion Loss (Appendix A, broad guidance):

Test Principle:

• Abrasive charge impacts concrete cube surface.
• Measure initial mass (M₁) and final mass (M₂).
• Abrasion loss = M₁ - M₂ (grams)

Notes:

• Values are tentative and for broad guidance only.
• Follow IS 2-1960 for rounding off results.
• Results help assess suitability of concrete mix for specific abrasion conditions.

flowchart LR
    A[Prepare Concrete Cube] --> B[Measure Initial Mass (M₁)]
    B --> C[Abrasion Test: Abrasive Charge Impingement]
    C --> D[Measure Final Mass (M₂)]
    D --> E[Calculate Abrasion Loss = M₁ - M₂]
    E --> F[Compare with Permissible Values]

This provides a practical approach to estimate abrasion resistance per IS 9284.