The liquid limit procedure is repeated until determinations are within certain ranges. What are the moisture content ranges?

The moisture content ranges for the liquid limit procedure are established to ensure that the results are consistent and reliable. In this context, the correct set of moisture content ranges is indeed 25-35, 20-30, and 15-25.

When performing the liquid limit test, the goal is to determine the water content at which a soil changes from a plastic to a liquid state. Multiple tests are conducted, and the measured liquid limits should fall within defined ranges before the testing can be considered complete. If the moisture contents from successive tests are within these specified ranges, it confirms that the liquid limit has been accurately determined and is reflective of the soil's behavior.

The choice of using moisture content ranges that gradually overlap, with the higher end of one range meeting the lower end of the next, helps to ensure that the right amount of moisture is being tested and allows for consistency across multiple tests. This methodology is important for characterizing the soil correctly, which is crucial for various engineering applications related to soil stability and suitability for construction purposes.