Liquid Limit of Soil

The liquid limit is the water content at which a fine-grained soil stops behaving as a plastic material and starts to flow like a liquid. It is determined using the Casagrande apparatus (counting the blows needed to close a standard groove in the soil paste) or the cone penetrometer method, both of which are permitted under IS 2720 (Part 5).

Liquid limit is one half of the Atterberg limits pair (with plastic limit) used to classify fine-grained soils and to estimate compressibility, shrink-swell behaviour and suitability as a construction material.