The ASTM D422 standard test method covers the determination of the particle-size distribution of soils, including gravel, sand, silt, and clay. The test method involves a series of sieving and sedimentation procedures to separate the soil particles into different size fractions. The results of this test are used to classify soils, estimate their engineering properties, and predict their behavior under various environmental conditions.
Engineers calculate the percentage of total mass retained on each sieve to determine the "cumulative percentage finer" than each size. Hydrometer Analysis
ASTM D422 is the bread and butter of soil mechanics. It is the first number we look at when deciding if a site is suitable for construction. While new standards have superseded the official ASTM designation, the principles of sieving and sedimentation remain the foundation of geotechnical laboratory testing. astm d422
If you are running the test or reviewing the data, watch out for these red flags:
From this curve, engineers extract three critical parameters: The ASTM D422 standard test method covers the
The test procedure outlined in ASTM D422 involves the following steps:
In this stage, a dry soil sample is passed through a series of nested sieves with decreasing aperture sizes. Engineers calculate the percentage of total mass retained
A hydrometer is used to measure the specific gravity of the suspension at timed intervals, which correlates to the amount of soil still in suspension. 3. Key Engineering Parameters