Methods of test for soils, Part 8: Determination of water content-dry density relation using heavy compaction

IS 2720 Part 8: Scope Overview

• Scope: This part of IS 2720 covers the determination of water content of soils by various methods.
• Applicable Sieves: Use IS sieves of 4.75 mm, 19 mm, and 37.5 mm conforming to IS 460 (Part 1)-1978 for sample preparation.
• Standards Referenced:
  • IS 2809-1972 for soil engineering definitions.
  • IS 460 (Part 1) for test sieves specifications.
• Compaction Moulds: Specifications for light and heavy compaction mould assemblies are provided for sample preparation.
• Rounding Off: Numerical values are to be rounded as per revised rules in the standard.

Key Formula for Water Content (w):

[ w = \frac{W_w}{W_s} \times 100 ]

Where:

• ( W_w ) = Weight of water in the soil sample
• ( W_s ) = Weight of dry soil

Summary Table: Sieve Sizes for Soil Preparation

This scope ensures consistent sample preparation and testing for accurate soil water content determination.

IS 2720 Part 8 (1983) - Key References & Specifications

• Test Sieves:

  • Use 4.75 mm, 19 mm, and 37.5 mm IS sieves conforming to IS 460 (Part 1)-1978 (Wire cloth test sieves).
  • These sieves are essential for particle size distribution in soil testing.

• Compaction Mould Assembly:

  • Specifications for light and heavy compaction moulds are provided (refer IS 2720 Part 8 for exact dimensions and material).

• Glossary & Symbols:

  • IS 2720 Part 8 refers to a glossary of soil engineering terms and symbols for consistency.

• Definitions:

  • Soil engineering terms follow IS 2809-1972 definitions.

Important Notes:

• Rounding off numerical values should follow the revised rules as per the standard.
• Always verify sieve specifications and compaction mould dimensions from the respective IS codes mentioned.

If you need specific formulas or tables for compaction or sieve analysis, please specify!

IS 2720 Part 8 (1983) - Apparatus for Compaction Test

Key apparatus specifications:

• Container (Clause 3.5):
  Airtight, non-corrodible container for water content determination.

• Sieves (Clause 3.7):
  IS sieves of sizes:

  • 4.75 mm
  • 19 mm
  • 37.5 mm
    Conforming to IS:460 (Part 1) - 1978 (wire cloth test sieves).

• Metal Rammer (Clause 3.9):
  Heavy compaction rammer as per IS:9189-1979.
  Typically:

  • Weight: 4.9 kg
  • Drop height: 450 mm

• Compaction Mould Assembly:
  For light and heavy compaction, as specified in IS 2720 Part 8.

Typical Compaction Test Setup

Compaction Energy Formula (for Heavy Compaction):

[ E = W \times H \times N ]

Where:

• (E) = Energy per unit volume (J/m³)
• (W) = Weight of rammer (N)
• (H) = Height of fall (m)
• (N) = Number of blows per layer × Number of layers

flowchart LR
    A[Soil Sample] --> B[Sieving (4.75 mm)]
    B --> C[Water Content Determination]
    C --> D[Compaction Mould Filling]
    D --> E[Compaction by Metal Rammer]
    E --> F[Measure Dry Density]

This summarizes the key apparatus and their specifications per IS 2720 Part 8 for soil compaction tests.

IS 2720 Part 8: Soil Specimen Preparation Key Points

• Sample Size:

  • Take a 5 kg air-dried soil sample passing through a 19 mm IS sieve (Clause 5.1.1).
  • For compaction tests, take five or more samples of 2.5 kg each, passing 19 mm sieve (Clause 5.2.1).

• Moisture Content:

  • Mix samples with varying water amounts to cover a range of moisture contents.
  • This range should include the moisture content at which maximum dry density occurs.

• Compaction:

  • Use a Heavy Compaction Rammer conforming to IS 9189-1979 (Clause 3.9).

Typical Procedure Summary

Moisture Content Calculation

[ w = \frac{W_w}{W_s} \times 100 ]

• (W_w) = Weight of water
• (W_s) = Weight of dry soil

Dry Density Calculation

[ \rho_d = \frac{\rho}{1 + w} ]

• (\rho) = Bulk density
• (w) = Moisture content (decimal)

flowchart LR
    A[Soil Sample (5 kg)] --> B[Pass 19 mm IS Sieve]
    B --> C[Divide into 2.5 kg samples]
    C --> D[Mix with varying water content]
    D --> E[Compact with Heavy Rammer (IS 9189)]
    E --> F[Determine Dry Density vs Moisture Content]
    F --> G[Find Maximum Dry Density]

This ensures accurate determination of compaction characteristics per IS 2720 Part 8.

IS 2720 Part 8 (1983) – Key Formulas, Tables & Specifications for Procedure

1. Sieve Specifications (Clause 3.7)

• Use IS sieves of 4.75 mm, 19 mm, and 37.5 mm conforming to IS:460 (Part 1)-1978 (Wire cloth test sieves).
• These sieves are essential for particle size analysis and soil grading.

2. Compaction Mould Assembly

• Specifications for light and heavy compaction moulds are standardized.
• Typical mould sizes:
  • Light compaction: 1000 cm³ volume
  • Heavy compaction: 2000 cm³ volume

3. Rounding Off Numerical Values

• Numerical results should be rounded off as per revised IS rules to maintain consistency.

4. Procedure for Soil Not Susceptible to Crushing (Clause 5.1)

• Use standard compaction procedure with specified moulds and sieves.
• Ensure soil gradation is maintained (no crushing during compaction).
• Follow compaction energy and moisture content guidelines as per IS 2720 Part 7 & 8.

Typical Formula for Dry Density (ρd):

[ \rho_d = \frac{W}{V \times (1 + w)} ]

• (W) = Weight of wet soil (g)
• (V) = Volume of mould (cm³)
• (w) = Moisture content (decimal)

Summary Table: IS Sieves

flowchart TD
    A[Start: Soil Sample] --> B[Sieving through IS 37.5 mm]
    B --> C[Sieving through IS 19 mm]
    C --> D[Sieving through IS 4.75 mm]
    D --> E[Comp

IS 2720 Part 8 (1983) - Key Formulas & Specifications for Calculations

This part deals with determination of water content of soils. While the provided context lacks explicit formulas, the standard references key practices:

Important Points:

• Rounding off: Values must be rounded as per IS 2:1960, retaining significant digits matching the standard's specified values.
• Sieves used: For soil gradation before testing, use IS sieves of 4.75 mm, 19 mm, and 37.5 mm conforming to IS 460 (Part 1)-1978.
• Compaction Moulds: Specifications for light and heavy compaction mould assemblies are provided for sample preparation.

Common Formula for Water Content (w):

[ w = \frac{W_w}{W_s} \times 100 ]

Where:

• ( W_w ) = Weight of water in the soil sample
• ( W_s ) = Weight of dry soil solids

Notes:

• Weight of water is obtained by subtracting dry weight from wet weight after oven drying at 105-110°C.
• Ensure proper sample size and preparation as per IS 2720 Part 8.

flowchart LR
    A[Soil Sample] --> B[Weigh Wet Soil (W_wet)]
    B --> C[Oven Dry at 105-110°C]
    C --> D[Weigh Dry Soil (W_dry)]
    D --> E[Calculate Water Content: w = ((W_wet - W_dry)/W_dry)*100]

Summary: Use IS sieves (4.75, 19, 37.5 mm), follow IS 2:1960 for rounding, and calculate water content by weight difference method.

IS 2720 Part 8 — Reporting of Results: Key Points

• Rounding Off:
  Results must be rounded per IS 2-1960 rules, keeping the same number of significant figures as specified in the standard.

• Dry Density vs. Moisture Content (Clause 6.3 & 7.1):

  • Plot dry density (γ_d) against moisture content (w).
  • Draw a smooth curve through the points.
  • Identify the maximum dry density on this curve (Optimum Moisture Content, OMC).

• Stone Content Reporting (Clause 7.4):

  • Report the percentage of stone retained on the 19 mm IS sieve to the nearest 1%.

Typical Reporting Format Example:

graph LR
A[Moisture Content (w)] --> B[Plot points]
B --> C[Draw smooth curve]
C --> D[Find Maximum Dry Density (γ_d max)]

This ensures clarity and consistency in reporting compaction test results per IS 2720 Part 8.

IS 2720 Part 8 - Notes and Precautions: Key Points

Though the code excerpt lacks explicit formulas or tables for notes and precautions, here are essential guidelines based on IS 2720 series and soil testing best practices:

Key Specifications & Precautions:

• Sieve Sizes: Use IS sieves of 4.75 mm, 19 mm, and 37.5 mm as per IS 460 (Part 1)-1978 for particle size analysis.
• Compaction Moulds: Use specified moulds for light and heavy compaction tests to ensure consistent sample volume.
• Rounding Off: Follow IS rules for rounding numerical values to maintain precision.
• Terminology: Use definitions from IS 2809-1972 for soil engineering terms.
• Sample Preparation: Ensure uniform moisture content and avoid contamination.
• Test Environment: Conduct tests at standard lab conditions to minimize variability.

Common Formulas (from IS 2720 series):

• Dry Density, ρd = (Mass of dry soil) / (Volume of soil)
• Water Content, w = (Mass of water / Mass of dry soil) × 100%

Summary Table: Typical IS Sieves

flowchart LR
    A[Soil Sample] --> B[Sieve Analysis]
    B --> C[Use IS Sieves 4.75, 19, 37.5 mm]
    B --> D[Compaction Test]
    D --> E[Light Compaction Mould]
    D --> F[Heavy Compaction Mould]
    E & F --> G[Calculate Dry Density and Water Content]

Always refer to IS 2720 Part 8 for detailed test procedures and IS 2809 for definitions.