With the Unified soil classification system, there are many ways of diagramming it. One of those was presented in the last post. With the AASHTO system, there’s generally only one, as shown in the Soils and Foundations Reference Manual. For classification this is pretty much it, but it’s not very informative when it comes to getting a “feel” for what these classifications mean.
Below is a chart from the Ohio Department of Transportation (about the only DOT I know of which uses the AASHTO system for just about everything they do) which describes each AASHTO classification in words and attempts to describe the type of soil for each type in the system.
vulcanhammer.net 
One thought on “Ohio DOT’s Rendition of the AASHTO Classification System”