Methods of Test for Aggregates for Concrete, Part I: Particle Size and Shape

IS 2386 Part 1 — Scope & Key Specifications

This part covers methods of test for aggregates used in concrete, focusing on particle size analysis and physical properties.

Key Specifications:

• Sieve Sizes (IS 460-1962):

• Thickness Gauge Dimension:

[ \text{Thickness Gauge} = 0.6 \times \text{Mean Sieve Size} ]

• Rounding Off: Follow IS 2-1960 rules for rounding test results.

• Test Equipment Accuracy: Balance accuracy should be ±0.1% of sample weight.

• Sieve Analysis Chart: Logarithmic scale for sieve size vs arithmetic scale for % passing.

Summary Diagram of Aggregate Testing Setup:

flowchart LR
    A[Sample Preparation] --> B[Sieve Nest]
    B --> C[Weigh Retained Material]
    C --> D[Calculate % Passing]
    D --> E[Plot Sieve Analysis Chart]
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IS 2386 Part 1 Key References & Specifications

1. Sieve Sizes (Clause 2.2.1, Table I)

• Square hole perforated plate sieves:
  80, 63, 50, 40, 31.5, 25, 20, 16, 12.5, 10, 6.3, 4.75 mm
• Fine mesh wire cloth sieves:
  3.35, 2.36, 1.18 mm, 600, 300, 150, 75 microns

2. Thickness and Length Gauges (Clause 5.2, Table V)

• Thickness Gauge = 0.6 × mean sieve size (mean sieve size = average of passing and retained sieve sizes)

3. Rounding Off (Clause 0.5)

• Follow IS 2-1960 rules for rounding numerical values.
• Maintain the same number of significant digits as specified.

This ensures standardization in sieve analysis and aggregate testing per IS 2386 Part 1.

IS 2386 Part 1 — Definitions & Key Specifications

1. Aggregate Size & Gauges (Clause 5.2, Table V)

• Thickness Gauge (mm) = 0.6 × Mean Sieve Size
• Dimensions for thickness and length gauges for various aggregate sizes:

2. Sieve Sizes for Aggregate Testing (Clause 2.2.1, Table I)

• Square hole, perforated plate sieves: 80, 63, 50, 40, 31.5, 25, 20, 16, 12.5, 10, 6.3, 4.75 mm
• Fine mesh, wire cloth sieves: 3.35, 2.36, 1.18 mm, 600, 300, 150, 75 microns

3. Reporting (Clause 2.6)

• Results must be calculated and reported as per the specified procedures.

This ensures standardized measurement and classification of aggregates for concrete testing per IS 2386 Part 1.

flowchart LR
    A[Aggregate Sample] --> B[Sieve Analysis]
    B --> C{Sieve Type

IS 2386 Part 1 – Apparatus Specifications

The apparatus for testing aggregates includes:

• Metal Cylinder

  • Capacity: ~3 litres
  • Shape: Diameter ≈ Height (e.g., 15 cm × 15 cm)
  • Material: Metal, thickness ≥ 3 mm
  • Requirement: Rigid to retain shape under rough usage

• Tamping Rod

  • Material: Metal
  • Shape: Circular cross-section
  • Diameter: 16 mm
  • Length: 60 cm
  • End: Rounded

• Balance

  • Capacity: 10 kg
  • Accuracy: Readable to 1 gram

• Scoop

  • Size: Approximately 20 cm × 12 cm × 5 cm
  • Capacity: About 1 litre (heaped)

These apparatus ensure consistency and accuracy in aggregate testing.

graph LR
A[Metal Cylinder] -->|15 cm dia & height| B[3 L Capacity]
C[Tamping Rod] -->|16 mm dia, 60 cm length| D[Rounded End]
E[Balance] -->|10 kg capacity| F[1 g readability]
G[Scoop] -->|20x12x5 cm| H[~1 L Capacity]

IS 2386 Part 1: Sampling and Sample Preparation Key Points

1. Minimum Sample Weights (Clause 2.3, Table II)

• Sample preparation: Use quartering or sample divider from the larger sample.

2. Equipment Specifications

• Balance: Accuracy of 0.1% of test sample weight.
• Sieve Nest: Two sieves - 75 micron IS sieve (lower) and approx. 1.18 mm IS sieve (upper).
• Container: Large enough for sample + water with vigorous agitation.
• Oven: Uniform temperature at 110 ± 5°C.

3. Sieve Sizes & Metal Gauges

• Use IS sieves as per Table V (not provided here).
• Metal gauges per IS 2386 figures (Fig. 2 & Fig. 3) for sample preparation.

4. General Notes

• Sampling must ensure representative material.
• Sample size depends on max particle size.
• Sieving and drying procedures standardized for consistency.

flowchart LR
    A[Larger Sample] -->|Quartering / Sample Divider| B[Sample for Sieving]
    B --> C[Sieving using IS Sieves]
    C --> D[Drying in Oven (110 ± 5°C)]
    D --> E[Testing]

For detailed sieve sizes and metal gauge patterns, refer to IS 2386 Part 1 figures and tables.

IS 2386 Part 1 — Key Test Procedures & Specifications

1. Thickness and Length Gauges (Clause 5.2, Table V)

2. Balance Requirements (Clauses 3.3.1 & 4.4.3)

• Accuracy: ±0.1% of test sample weight.
• Capacity: Sufficient for test sample size.

3. Sieves

• Use IS standard sieves (e.g., 75-micron and 1.18-mm for fines).
• Sizes as per Table V for aggregate gradation.

4. Test Sample Preparation

• Container: Large enough to hold sample + water for agitation.
• Oven: Maintain uniform temperature of 110°C ± 5°C for drying.

5. Rounding Off (Clause 0.5)

• Follow IS 2-1960 rules.
• Retain significant digits as per specified values.

6. Additional Notes

• Thickness gauge dimension = 0.6 × mean sieve size.
• Use metal gauge as per Fig. 2 (not shown here) for thickness measurement.

flowchart TD
    A[Sample Collection] --> B[Weigh Sample (Balance ±0.1% accuracy)]

IS 2386 Part 1: Determination of Material Finer than 75 Microns

Key Equipment & Specifications (Clause 3.3.1)

• Balance: Accuracy of 0.1% of test sample weight.
• Sieves:
  • Lower sieve: 75-micron IS sieve.
  • Upper sieve: ~1.18-mm IS sieve (per IS 460-1962).
• Container: Large enough for sample + water, allowing vigorous agitation without loss.
• Oven: Maintains uniform temperature of 110°C ± 5°C.

Calculation (Clause 3.5)

[ \text{Percentage finer than 75 microns} = \frac{B - C}{B} \times 100 ]

Where:

• ( A ) = % finer than 75 microns
• ( B ) = Original dry weight of sample (g)
• ( C ) = Dry weight after washing (g)

Graphical Recording (Clause 2.6.1 & Fig. 1)

• Use cumulative % passing plotted on a logarithmic scale for aperture size.
• Vertical scale: Arithmetic (% passing).
• Horizontal scale: Logarithmic (aperture size in microns).

Summary Table: Equipment & Conditions

This method ensures precise quantification of fines (<75 microns) critical for aggregate quality control in concrete.

IS 2386 (Part 1) - Sieve Analysis of Aggregates: Key Points

1. Sieve Sizes (Clause 2.2.1, Table I)

• Square hole perforated plate sieves:
  80, 63, 50, 40, 31.5, 25, 20, 16, 12.5, 10, 6.3, 4.75 mm
• Fine mesh wire cloth sieves:
  3.35, 2.36, 1.18 mm, 600, 300, 150, 75 microns

2. Minimum Sample Weight for Sieving (Table IV)

3. Maximum Weight Retained on Sieve (Table III)

• Limits depend on sieve diameter (45 cm or 30 cm) and sieve size.
• Example: For 50 mm sieve, max weight retained = 10 kg (45 cm sieve), 4.5 kg (30 cm sieve).

4. Thickness Gauge Dimension (Table V)

• Thickness gauge = 0.6 × mean sieve size
• Example: For 50 mm sieve, thickness gauge = 0.6 × 45 mm = 27 mm

5. Calculation of Weighted Percentage (Clause 4.5.1)

• Weighted % = (Mass % passing gauge in fraction) × (Mass % of fraction in total sample)

Summary Formula for Thickness Gauge

[ \text{Thickness Gauge} = 0.6 \times \text{Mean Sieve Size} ]

Visual: Sieve Sizes Hierarchy

graph TD
    A[80 mm]

IS 2386 (Part 1) – Particle Shape Determination

The standard focuses on particle size and shape assessment by sieve analysis and gauge tests.

Key Steps & Formula (Clause 4.5.1):

• For each sieve fraction:
  • Calculate x = (Mass of pieces passing the gauge in that fraction) / (Total mass of pieces in that fraction) × 100%
  • Calculate y = (Total mass of pieces in that fraction) / (Total mass of sample retained on 6.3 mm sieve) × 100%
• Weighted percentage passing gauge for each fraction = x × y

This weighted value helps assess particle shape characteristics (e.g., flaky or elongated particles).

Additional Notes:

• The sample considered is the aggregate retained on the 6.3 mm sieve.
• Amendments include substitution of a value in Fig. 3 for shape factor from 58.5 to 64.4.

Summary Table (Conceptual):

This method quantifies particle shape to ensure aggregate suitability for concrete, minimizing flaky/elongated particles that weaken mix strength.

IS 2386 Part 1: Calculation and Reporting of Results

Key Points from Clauses 2.6 & 4.5

• Clause 2.6: Results must be calculated and reported clearly as per the test or analysis performed.

• Clause 4.5:

  • Final values (observed or calculated) should be rounded off according to IS 2:1960 (Rules for Rounding Off Numerical Values).
  • The number of significant figures in the reported result should match the number of significant figures in the specified value of the standard.

Important Specifications:

Example of Rounding Off (IS 2:1960):

• If specified value = 12.3 (3 significant figures), report result as 12.3 or 12.4, not 12.345.
• If specified value = 0.123 (3 significant figures), report result as 0.123 or 0.12, not 0.12345.

flowchart LR
    A[Test/Analysis] --> B[Calculate Result]
    B --> C{Round off as per IS 2:1960}
    C --> D[Match Significant Figures]
    D --> E[Report Final Value with Units & Conditions]

This ensures consistency, clarity, and compliance with IS 2386 Part 1 reporting requirements.

IS 2386 Part 1: Precision and Accuracy Key Points

1. Balance Accuracy

• Must have accuracy of 0.1% of the test sample weight (Clauses 4.4.3a, 5.4.3a, 2.2.2).
• Sensitivity should match the test sample size for precise measurements.

2. Metal Gauge

• Must conform to the specific pattern shown in Fig. 2 (Clause 4.4.3b) and Fig. 3 (Clause 5.4.3b).
• Ensures consistent sample thickness or dimension control during tests.

3. Sieves

• Use IS standard sieves with sizes specified in Table V (Clauses 4.4.3c, 5.4.3c).
• Critical for particle size distribution accuracy.

4. Rounding Off

• Final test values must be rounded as per IS 2:1960 rules.
• Retain the same number of significant digits as the specified value (Clause 0.5).

Summary Table for Balance Accuracy

flowchart LR
    A[Test Sample] --> B[Weigh on Balance]
    B -->|Accuracy ±0.1%| C[Record Weight]
    C --> D[Use Metal Gauge (Fig. 2/3)]
    D --> E[Sieving with IS Sieves (Table V)]
    E --> F[Data Rounded per IS 2:1960]

This ensures high precision and accuracy in aggregate testing per IS 2386 Part 1.

IS 2386 (Part 1) - Key Notes, Tables & Specifications

1. Dimensions of Thickness and Length Gauges (Clause 5.2, Table V)

• Thickness Gauge = 0.6 × mean sieve size

2. Sieve Specifications (Clause 2.2.1, Table I)

• Square hole perforated plate sieves: 80, 63, 50, 40, 31.5, 25, 20, 16, 12.5, 10, 6.3, 4.75 mm
• Fine mesh wire cloth sieves: 3.35, 2.36, 1.18 mm and 600, 300, 150, 75 microns

3. Material Finer than 75 Microns (Clause 3.3.1)

• Balance accuracy: 0.1% of sample weight
• Sieves: Nest of 75-micron and ~1.18-mm IS sieves (per IS:460-1962)
• Oven: Maintain 110°C ± 5°C for drying

4. Rounding Off (Clause 0.5)

• Follow IS 2-1960 rules
• Retain significant figures equal to specified values

Summary Diagram: Thickness Gauge Calculation

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