Test Method Title
Standard Method of Test for Determining the Plastic Limit and Plasticity Index of Soils
Reference Number
AASHTO T 90
Material
Soil
Test Property
Plastic Limit
Description of Test
The Plastic Limit of a soil is the lowest water content at which the soil remains plastic. Soil is rolled into a 3 mm diameter thread at a rate of 80-90 strokes per minute on a glass plate. It is then broken into 6-8 pieces, squeezed together and re-rolled until the soil can no longer be rolled into a thread. At this time, the moisture content of the crumbled pieces are measured.
Number of Test Specimens
2
Test Specimen Size
15 grams of material passing the #40 sieve, total
Keywords
Atterberg Limits, Limits, Plastic Limit