Methods of Test for Aggregates for Concrete, Part V: Soundness
1963 Edition

Overview of Soundness Testing

• Defines the technical scope for evaluating aggregates' resistance to weathering-induced disintegration.
• Excludes contractual stipulations.
• Emphasizes rounding conventions as per IS 2:1960.

Essential Sieves (Clause 2.1)

• Conformance to IS 460:1962 mandatory.

Test Data Recording (Clause 9.2, Table I)

• Parameters include sieve size, percentage grading, initial weight, percentage passing after test, and weighted average loss.
• Separate consideration given to fine and coarse aggregates.

Rounding Guidelines

• Follow IS 2:1960 for numerical rounding maintaining significant digits.

flowchart TD
    A[Aggregate Sample] --> B[Sieving as per IS 460]
    B --> C[Conduct Soundness Test]
    C --> D[Record Weight and Grading Data]
    D --> E[Compute Weighted Loss Percentage]
    E --> F[Apply Rounding Rules]
    F --> G[Evaluate Aggregate Quality]

Overview of Apparatus

Sieves (Clause 2.1)

• Square mesh sieves per IS 460-1962.
• Fine series include 0.15 to 4.75 mm sizes.
• Coarse series between 8 mm and 80 mm.

Drying Oven (Clause 2.5)

• Operating temperature: 105°C to 110°C.
• Evaporation rate must be at least 25 grams per hour over 4 hours with door closed.
• Verified by water loss from beakers at controlled temperature.

Data Recording (Clause 9.2)

• Use Table I format documenting sieve size, grading percentage, initial weight, post-test percentage passing, and weighted average loss.

graph LR
A[Sieves] --> B[Fine Range: 0.15 - 4.75 mm]
A --> C[Coarse Range: 8 - 80 mm]
D[Drying Oven] --> E[Temp: 105-110°C]
D --> F[Evaporation ≥ 25 g/h]
G[Soundness Data] --> H[Record and Calculate Loss]

Sample Requirements (Clause 4.1)

• Fine aggregates should pass through a 10 mm IS sieve.
• Minimum 100 grams required for each size fraction representing at least 5% of the total sample.

Size Fractions

Sieving Details

• Use IS 460:1962 compliant sieves.
• Fine series: 150, 300, 600 μm, 1.18, 2.36, 4.0, 4.75 mm.
• Coarse series: 8, 10, 12.5, 16, 20, 25, 31.5, 40, 50, 63, 80 mm.

Loss Calculation

• If any size fraction is under 5% of total weight, assign percentage loss from the next smaller fraction.

Data Recording

• Capture sieve size, grading percentage, pre-test weight, post-test percentage passing, and weighted average loss.

Fine Aggregate Criteria (Clause 4.1)

• Must pass through the 10 mm sieve.
• Each size fraction making up 5% or more of the sample must weigh at least 100 grams.

Coarse Aggregate Criteria (Clause 4.2)

• Remove particles finer than 4.75 mm.
• Minimum sample weights vary by size fraction, for example: | Size Range (mm) | Required Weight (g) | Notes | |-----------------|--------------------|-------| | 10 - 4.75 | 300 | | | 20 - 10 | 1000 | Composition ratio specified | | 40 - 20 | 1500 | Composition ratio specified | | 63 - 40 | 3000 | Composition ratio specified | | ≥ 80 | 3000 | Size distribution required |

Reporting Format

• Document sieve sizes, grading percentages, weights before testing, percentage passing after testing, and weighted average corrected loss.

Notes

• If a fraction is less than 5%, use loss from adjacent sizes.
• Larger sample sizes are permissible.

Sample Grading and Size (Clause 4.1 & 4.4)

• Fine aggregates to pass through 10 mm sieve.

• Each size fraction with ≥5% content must provide at least 100 g.

• Size divisions as follows: | Passing Sieve | Retained On | |---------------|-------------| | 600 μm | 300 μm | | 1.18 mm | 600 μm | | 2.36 mm | 1.18 mm | | 4.75 mm | 2.36 mm | | 10 mm | 4.75 mm |

• For fractions under 5%, assign loss as average of neighboring fractions.

Sieves Specification (Clause 2.1)

Calculation of Weighted Average Loss

• Use weighted sum of percent loss multiplied by weight fraction before testing.

Equipment (Clause 2.1)

• Employ sieves conforming to IS 460:1962 standards.
• Fine sieves: 150, 300, 600 μm, 1.18, 2.36, 4.75 mm.
• Coarse sieves: 8 to 80 mm range.

Quantitative Analysis (Clause 7.1)

• After completing the final cycle and cooling, wash samples to eliminate sulphate residues verified by BaCl2 test.
• Dry samples at 105–110°C to constant weight.
• Sieve samples according to aggregate sizes: | Aggregate Size (mm) | Sieve for Loss Analysis (mm) | |---------------------|------------------------------| | 63 - 40 | 31.5 | | 40 - 20 | 16 | | 20 - 10 | 8 | | 10 - 4.75 | 4 |

Reporting (Clause 9.2)

• Record sieve size, grading percentage, initial weight, post-test percentage passing, and weighted average corrected loss.

Rounding

• Round results in accordance with IS 2:1960, preserving significant figures.

Procedure (Clause 7.1)

• Following the final immersion cycle and cooling, wash the specimen to remove residual sulphates confirmed by BaCl2 test.
• Dry fractions at 105–110°C to constant weight and weigh each.
• Sieve according to size: | Aggregate Size (mm) | Sieve for Loss Determination (mm) | |---------------------|----------------------------------| | 63 - 40 | 31.5 | | 40 - 20 | 16 | | 20 - 10 | 8 | | 10 - 4.75 | 4 |

Recording

• Use Table I format capturing sieve size, grading, pre-test weight, post-test passing percentage, and weighted average loss.

Additional Notes

• Qualitative inspection involves visual assessment of fragmentation types.
• Combined post-test fractions should be sieved to obtain cumulative percentage retained on standard sieves.

Visual Inspection (Clause 8.2)

• Examine each fraction for signs of excessive grain splitting, disintegration, cracking, flaking, or crumbling.
• Focus primarily on particles larger than 20 mm but also inspect smaller sizes.

Sieve Analysis After Testing

• Combine all fractions and detritus.
• Perform sieve analysis using sizes: 150, 300, 600 μm, 1.18, 2.36 mm, 4.75, 10, 20, 40, and 80 mm.
• Record cumulative percentage retained.

Quantitative Steps

• Wash sample to remove sulphate residues using BaCl2 test.
• Dry at 105–110°C to constant weight.
• Sieve according to aggregate size classifications.

flowchart TD
    A[Post-Test Sample] --> B[Wash and BaCl2 Test]
    B --> C[Dry at 105-110°C]
    C --> D[Weigh and Sieve Fractions]
    D --> E{Particle Size}
    E -->|>20 mm| F[Visual Damage Evaluation]
    E -->|≤20 mm| G[Optional Visual Inspection]
    D --> H[Record Cumulative % Retained]

Reporting Requirements (Clauses 9.1 & 9.2)

• Include weights of individual size fractions before testing.
• Document percentage finer by weight for each fraction.
• Calculate and report weighted average percentage loss using grading data.
• For particles over 20 mm, count total and damaged particles (disintegration, cracking, etc.).
• State solution type used (Na2SO4 or MgSO4).

Rounding

• Follow IS 2:1960 rounding practices maintaining significant digits.

Suggested Reporting Table (Table I)

Calculation

• Weighted average loss computed as sum of (grading % × loss %) divided by 100.

Data Recording (Clause 9.2)

• Use standardized forms capturing sieve sizes (ranging from 150 μm to 63 mm), weights before and after testing, and computed weighted average losses.

Quantitative Examination (Clause 7.1)

• After final test cycle and cooling, wash samples free of salts (verified with BaCl2).
• Dry at 105–110°C to a constant weight.
• Sieve fine aggregates using original sieves and coarse aggregates with specified sieve sizes based on their dimensions.

Sieves Specifications (Clause 2.1)

• Employ sieves complying with IS 460:1962.
• Fine sieve sizes: 0.15, 0.3, 0.6, 1.18, 2.36, 4.75 mm.
• Coarse sieve sizes: 8, 10, 12.5, 16, 20, 25, 31.5, 40, 50, 63, 80 mm.

Rounding Procedures (Clause 0.5)

• Round off results as per IS 2:1960, preserving the significant figures of the reported values.

Weighted Average Loss Formula

• Weighted average loss is the sum of each fraction's percentage loss multiplied by its grading percentage, divided by 100.