Mechanical Soil Compactor, California Method 216

Mechanical Soil Compactor – California Method 216

The California Modified Automatic Soil Compactor is designed for precise and repeatable soil compaction testing. It is commonly used in laboratories and field testing environments to meet California Method 216, ASTM, and AASHTO requirements.

The unit is supplied with a 2 in (51 mm) round 10 lb hammer, factory-installed with a standard round face. The piston and rod are included as part of the machine. Molds, alternative hammers, and accessories are available separately.

• Dimensions: 24 × 18 × 36 in
• Weight: 150 lb

Explore more options in
Soil Compaction Equipment.

Compatibility and Compaction Setup

The compactor is compatible with 4 in (102 mm) ID molds and supports a 5.5 lb (2.5 kg) hammer with a 12 in (305 mm) drop. A compaction mold is required to hold the soil securely during testing and ensure uniform density.

The standard round hammer can be replaced with a pie-shaped face hammer of the same 3.14 in² area. This option is ideal for covering the full sample surface when using 6 in molds.

Key design features include:

• Hammer lift that compensates for soil thickness
• Free-fall hammer with weight concentrated at the foot
• Adjustable hammer weight from 5.5 to 10 lb using surcharge weights

These features ensure accurate calibration and consistent results across different soil types.

Standards Compliance

The round base supports the compaction molds and promotes even compaction. This ensures compliance with major international testing standards, including:

Meets Test Methods:

• AASHTO T99, T134, T135, T136, T180, T192, T220
• ASTM D698, D1557, D1558, D558, D559, D560
• BS 1377, BS 1994

For cement fineness calibration, reference materials such as
NIST 114R Portland Cement Fineness SRM are recommended.

Related tools can be found under
Soil Testing Equipment.

Understanding Soil Compaction

Soil compaction is a critical process in construction, geotechnical engineering, and quality control testing. It increases soil density to improve strength, stability, and load-bearing capacity.

Mechanical compaction is preferred over manual methods because it:

• Reduces operator error
• Improves repeatability
• Meets standardized testing requirements

Automatic compactors are commonly used to determine:

• Maximum dry density
• Optimum moisture content

These values are essential for safe and durable construction.

Development of Mechanical Soil Compactors

Early soil compactors required manual hammer drops, which led to inconsistent results and operator fatigue. This changed with the introduction of automatic soil compactors in the mid-20th century.

Key advancements include:

• 1950s–60s: Hammer lift mechanisms and rotating bases
• 1970s–80s: Digital counters and adjustable hammer weights
• 1990s–2000s: Computerized controls, data logging, and safety interlocks

Modern compactors use solid-state electronics for consistent performance, improved safety, and reduced maintenance.

Features and Specifications

The Automatic Soil Compactor is built for efficiency and precision.

Features:

• Automatic mold rotation after each hammer blow
• Independent start/stop controls
• Preset number of blows for standard or modified tests
• Adjustable rammer height and weight
• Solid-state controls for durability
• Automatic digital counter (≈26 blows/minute)

A calibration kit is recommended to verify hammer height and drop accuracy.

Parts and Accessories

Standard components include:

• Hammer and surcharge weights
• Compaction mold
• Base plate for stability
• Digital counter for blow tracking

Accessories allow the system to be configured for different test standards and soil types.

View compatible accessories under
Soil Compaction Accessories.

Operation and Maintenance

For best performance:

• Operate the compactor only by trained personnel
• Follow manufacturer setup instructions
• Inspect moving parts regularly
• Clean and lubricate components as required

Routine maintenance ensures accurate test results, safe operation, and long equipment life.