ASTM D6913 Standard Test Methods for Particle-Size Distribution (Gradation) of Soils Using Sieve Analysis

Get Certified ASTM D6913 Testing for Reliable Soil Gradation Evaluation 

Soil particle-size distribution affects important engineering characteristics such as hydraulic conductivity, compressibility, and shear strength. ASTM D6913 provides a controlled sieve-analysis procedure that laboratories can use to quantify the distribution of soil particles within the applicable size range. Engineers use the resulting gradation data to classify soils, evaluate construction materials, select fill materials, and assess drainage requirements. The standard also allows for the calculation of the coefficient of uniformity and the coefficient of curvature from the particle-size distribution curve.

• Determines soil particle-size distribution and gradation between 75 mm and 75 μm.
• Uses square-opening sieves for particle separation and provides single sieve sets and composite sieving procedures.
• Provides Method A and Method B and allows moist, air-dried, and oven-dried specimen processing.
• Supports washing and dispersion procedures and provides minimum specimen-mass requirements.

What are the uses of ASTM D6913 testing? 

Laboratories use ASTM D6913 testing to identify soil gradation for geotechnical and construction applications. Engineers use this method to evaluate how soil composition may affect engineering performance. This standard:

• Determines particle-size distribution of soils, helping calculate the coefficient of uniformity and the coefficient of curvature.
• Helps evaluate highway embankment materials and supports backfill evaluation and selection of earthen-dam materials.
• Supports drainage-filter design and quality control and evaluates groundwater drainage materials.
• Supports selection of dynamic compaction and grouting approaches.

Which Materials Can Be Tested Under ASTM D6913? 

ASTM D6913 primarily applies to soils containing particles between 3 in. (75 mm) and No. 200 (75 μm). The standard may also apply to some particle-based materials that are not technically soil but meet the following requirements.

Why is ASTM D6913 Important?

ASTM D6913 provides a standardized method for measuring soil gradation. Particle-size distribution strongly influences the engineering behavior of soil and helps engineers understand the relative proportions of coarse and fine particles.

ASTM D6913 Testing Process and Data Collection

Technicians first take the representative soil samples, determine their maximum particle size, and select appropriate specimen mass and processing procedure. Then, they use a moist, air-dried, or oven-dried procedure based on soil characterization. Next, technicians disperse and wash the specimens and place them on the selected sieve set, shake the sieve mechanically or manually, and determine the mass retained on each sieve. The laboratory then calculates the percentage passing each sieve and develops the particle-size distribution curve.

ASTM D6913 Common challenges and troubleshooting

Soil gradation may vary based on representative sampling, specimen preparation, sieve selection, specimen mass, and weighing and sieving equipment. Common challenges include sieve overloading, inadequate specimen dispersion, incomplete washing of fine particles, material loss during transfer, incorrect specimen mass, improper sieve selection, and inconsistent drying conditions. The technician should check sieves and mechanical sieve shakers, determine the correct specimen weight, avoid loading the sieves, and note any procedural changes. ASTM D6913 specifically notes that personnel competence and suitable equipment and facilities affect result quality.