This lecture reviews the Atterberg limits and why they are important to geotechnical engineers. Some basic information about the liquid limit and plastic limit tests are provided. Some basic properties like the plasticity index, the liquidity index, and the activity of a soil are introduced and briefly discussed.

Link to an example of a liquid limit test: http://www.youtube.com/watch?v=pfEWVfqB8eg

Critical Questions to Consider:
1) What are the Atterberg limits, and why are they important to geotechnical engineers?

2) Why would the volume and consistency behavior of soil in the presence of water be a useful thing for geotechnical engineers to understand?

3) What is the difference between the hydrometer test and the Atterberg limit test? Why would both of these tests be important and useful?

4) What are some of the common uses for the Atterberg limits?