Test Method Title
Standard Test Method for Dispersive Characteristics of Clay Soil by Double Hydrometer
Reference Number
ASTM D4221
Material
Soil
Test Property
Percent Dispersion
Description of Test
The percent passing the 5-µm size is determined using test procedures in Test Method D422. The percent passing the 5-µm size is determined using the test procedures in this test method. This test method differs from Test Method D422 primarily in that no mechanical agitation nor chemical dispersants are used. The percent dispersion is calculated by dividing the percent passing the 5-µm size using this test method by the percent passing the 5-µm size obtained using Test Method D422 and by multiplying the result by 100.
Number of Test Specimens
2
Test Specimen Size
Material passing #10 sieve of 115 grams for sandy soil and 65 grams for silt and clay soil
Keywords
Clays, deflocculation, dispersion, dispersion clay, erosion, hydrometer analysis, jugging, particle size, piping.