ASTM D6128 Standard Test Method for Shear Testing of Bulk Solids Using the Jenike Shear Tester

Get Certified ASTM D6128 Bulk Solids Shear Testing

ASTM D6128 testing provides important flow-property data for engineers designing storage bins, hoppers, and other bulk-solid handling systems. A qualified technician uses a Jenike shear tester to evaluate the material under controlled normal and shear loading conditions.

• Cohesive Strength: Determines the resistance of bulk solids to shear.
• Internal Friction: Evaluates frictional behavior within the bulk solid.
• Bulk Density: Measures the density of the tested bulk material.
• Wall Friction: Determines friction between the bulk solid and selected wall surfaces.
• Flow Assessment: Provides data for evaluating bulk-solid flow through storage and handling equipment.
• Limitations: The method is not applicable when the material cannot reach the required steady-state condition within the shear cell’s travel limit.

What are the uses of ASTM D6128 testing?

ASTM D6128 data help engineers understand how bulk solids behave during storage and discharge. The results are particularly useful when designing equipment that must maintain reliable and controlled material flow. This test covers:

• Hopper and Bin Design: Supports the design of storage equipment to reduce arching and ratholing.
• Mass-Flow Design: Helps determine suitable hopper-wall slope and smoothness.
• Flowability Evaluation: Characterizes the tendency of powders and bulk solids to flow or resist movement.
• Wall-Surface Selection: Provides wall-friction data for selecting suitable contact surfaces.
• Structural Design: Supplies flow-property parameters that may support the design of storage and handling equipment.

Which Materials Can Be Tested According to ASTM D6128?

ASTM D6128 is intended for bulk solid materials whose shear behavior can be evaluated using the Jenike shear tester. The method can be used to characterize materials under continuous flow and storage-at-rest conditions. This test applies to:

• Powders: Fine bulk materials requiring controlled flow assessment.
• Granular Solids: Coarse or granular materials handled in bins and hoppers.
• Cohesive Bulk Solids: Materials whose flow behavior is strongly affected by cohesive strength.
• Fine Fractions: For materials containing a significant proportion of particles finer than approximately 6 mm, cohesive strength and wall-friction testing may be performed on the fine fraction.

Why is ASTM D6128 Testing Important?

Bulk solids flow problems include arching, ratholing, flooding, segregation, loss of usable storage capacity, and caking, all of which are prevented by reliable flow. Engineers can use controlled shear-property data from ASTM D6128 to design bins and hoppers to minimize these issues.

ASTM D6128 Testing Process and Data Collection

The technician prepares the bulk-solid specimen and establishes the required testing conditions. The Jenike shear tester applies controlled normal and shear forces while the technician records the material response. The technician collects measurements under the required loading conditions and evaluates them to establish the material’s shear and flow properties. ASTM D6128 uses SI units as the standard units of measurement, and observed and calculated values are reported according to the applicable significant-digit and rounding requirements.

Common Challenges and Troubleshooting

Variations in sample condition can affect measured shear properties. Technicians should prepare representative specimens consistently. Some materials may not reach the required steady-state condition within the shear-cell travel limit. Such materials are outside the applicable testing range of the method. Inconsistent normal or shear loading can affect the measured response. Calibrated equipment and controlled loading are essential. Wall-friction results can change with the surface material and condition. Technicians should use the specified wall surface and maintain consistent test conditions.

• The report should identify the tested bulk solid and provide the measured shear data and calculated flow-property parameters, including the applicable cohesive strength, internal friction, bulk density, and wall-friction results.
• Results are reported using SI units, with observed and calculated values rounded according to the applicable requirements.
• The technician records the specimen identification, loading conditions, measurements, and relevant test observations.
• The analyst documents the calculated flow properties and evaluates the results for their intended storage or handling application.
• The final report contains the specimen details, measurement data, test conditions, calculations, and other necessary reporting details.

Link to ASTM D6128