AASHTO T 215-14 (2018) PDF Download

The AASHTO T 215-14 (2018) standard outlines a procedure for determining the permeability of water through granular (cohesionless) soils in a steady-state condition. The method is based on Darcy's Law, which states that the coefficient of permeability is the ratio of the flow rate to the hydraulic gradient.

This test is specifically designed for disturbed granular soils that contain less than 10 percent by mass of material passing the 75-µm (No. 200) sieve. Soils with a significant amount of material smaller than the 75-µm (No. 200) sieve may experience consolidation effects that can influence the test results. In such cases, a different test procedure, such as the ASTM D 5084 method, should be used to determine the permeability of fine-grained and cohesive soils.

The AASHTO T 215-14 standard provides two methods of test, Method A and Method B, depending on the specific permeameter used. The chosen method will be based on the equipment available for conducting the permeability test.