Methods of test for soils, Part 1: Preparation of dry soil samples for various tests

IS 2720 Part 1 - Scope: Key Specifications & Tables

This part of IS 2720 covers methods of test for soils, including sample preparation, drying, pulverization, and quantity requirements for various tests.

1. Sample Preparation & Drying

• Drying temperature: Oven at 105-110°C ± 5°C (typically 24 hours).
• Air drying allowed for some tests (e.g., shrinkage factors, direct shear).

2. Quantity of Soil Sample & Pulverization (Passing Sieve Size)

IS 2720 Part 1: Apparatus Key Specifications

Drying Apparatus (Clause 2.6)

• Drying Oven: Thermostatically controlled, non-corroding interior.
• Temperature: Maintained between 105°C and 110°C.
• Duration: Typically 24 hours for drying soil samples.

Sample Preparation (Clause 9.5, Tables)

Notes:

• Sample pulverization depends on test type; finer sieves (e.g., 425 micron) for chemical tests.
• Air drying is used for tests sensitive to oven drying.
• Oven drying at 105-110°C for 24 hours is standard for moisture and chemical content determination.

flowchart TD
    A[Soil Sample] --> B{Test Type

IS 2720 Part 1 - Preparation of Soil Samples for Tests

Key Specifications from Table 1 (Clause 3.3, 4.75, 9.5):

IS 2720 Part 1: Quantity of Soil Sample for Laboratory Tests

Key Points & Tables:

1. Quantity of Sample (Clause 4.1 & Table 1)

• Quantities vary by test type; refer to specific IS 2720 parts for exact values.
• Representative sampling from large soil mass by quartering or riffling (Clause 4.2).
• For coarse gravel, quartering by cone is avoided; use quadrant mixing.

2. Sample Quantity for Water Content (Table 2)

3. Sample Quantity for Various Tests (Table 1 Extract)

IS 2720 Part 1: Drying of Soil Samples - Key Points

Drying Temperature & Duration

• Oven drying temperature should not exceed 110°C.
• Soils with organic or calcareous content: max 60°C to avoid alteration.
• Typical drying: 105-110°C for 24 hours for most tests.

Drying Apparatus (Clause 2.6)

• Thermostatically controlled oven maintaining 105-110°C.
• Interior made of non-corroding material.

Drying Requirements for Specific Tests (Summary from Table 1)

Notes:

Detailed content not available.

IS 2720 Part 1: Pulverizing and Sieving Procedures - Key Points

Pulverizing Procedure (Clause 3.3)

• Break large clods with a wooden mallet.
• Further pulverize using a pestle and mortar or mechanical device with rubber-covered pestle.
• Pass pulverized soil through the specified sieve.
• Re-pulverize soil retained on sieve until minimal soil passes through.
• Avoid breaking individual soil particles.

Pulverizing Apparatus (Clause 2.3)

• Use mortar and rubber-covered pestle (manual or power-driven).
• Soft wood pestle and mortar also acceptable.

Degree of Pulverization & Sample Size (Table 1 Summary)

Important Notes

• Pulverization sieve size depends on test type.
• Pulverization aims to break aggregates, not individual grains.
• Sample drying temperature usually 105-110°C for 24 hours unless otherwise specified.

Summary Diagram of Pulverizing Procedure

flowchart TD
    A[Collect Soil Sample] --> B[Break Large Clods with Wooden Mallet]
    B --> C[Pulverize in Mortar & Pestle]
   

Detailed content not available.

Rounding Off of Test Results (IS 2720 Part 1)

• Clause 0.3: Final test values (observed or calculated) shall be rounded off as per IS:2-1960 (Rules for rounding off numerical values).
• The number of significant figures retained in the rounded value must match that of the specified value in the standard.

Key Points from IS 2720 Part 1 - Sample Preparation & Testing

IS:2-1960 Rounding Rules Summary

• If the digit to be dropped is <5, drop it and leave preceding digit unchanged.
• If the digit to be dropped is >5, increase preceding digit by 1.
• If the digit to be dropped is 5, round to nearest even digit.

flowchart TD
    A[Test Result (Observed/Calculated)] --> B[Check Specified Value Precision]
    B --> C[Round off as per IS:2-1960]
    C --> D

IS 2720 Part 1 - References to Other Parts: Key Table Summary

This part serves as a guide to sample preparation and links to specific test methods in other parts of IS 2720.

IS 2720 Part 1 (1983) — Key Annexure Tables & Specifications

1. Sample Preparation & Drying Conditions

• Drying Temperature: Oven at 105-110°C ± 5°C for 24 hours (typical for moisture content, specific gravity, unconfined compressive strength).
• Air drying used for tests like shrinkage factors, direct shear, consolidation properties.

2. Quantity of Soil Sample Required (Selected Tests)

3