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Dry unit weight

It is defined as “ the weight of soil solids per unit total volume of sample”

Dry Unit Weight of Soil = ( Weight of Soil Solids/Total Volume of Soil)

Since

W = Wa + Ww + Ws = 0 + 0 + Ws = Ws = Wd , therefore,

When all the voids of soil are filled with air it is called Dry Soil and Unit Weight as Dry Unit Weight e.g. Oven Dried Soil in Laboratory

VIDEOS
Determination of Dry Density of Soil by Core Cutter Method
Determination of Dry Density of Soil by Sand Replacement Method
Determination of Dry Density of Soil by Sand Replacement Method

AS PER IS-( INDIAN STANDARD)
IS 13468 (pdf) 1992 Apparatus for determination of dry density of soil by core cutter method-
IS 2720-28 Determination of dry density of soils, in-place, by the sand replacement method
IS-2720-29 Determination of Dry Density of Soils In-place by the Core-cutter Method

1. Liquid limit The water content at which the soil has such a small shear strength that it flows to close a groove of standard width when jarred in a specified manner. The Liquid Limit, also known as the upper plastic limit, is the water content at which soil changes from the liquid state to a plastic state. OR It is the minimum moisture content at which a soil flows upon application of very small shear force. Liquid Limit (LL or WL) ‑ the water content, in percent, of a soil at the arbitrarily defined boundary between the semi‑liquid and plastic states. Liquid limit is defined as “ the moisture content at which soil changes from liquid state to plastic state” According to Casagrande Liquid Limit Test it is also defined as “ the moisture content at which two sides of a groove come close together for a distance of 12.7 mm under the impact of 25 number of blows” According to fall cone test method Liquid Limit is also defined as “the moisture content at which the cone( fall cone test) penetrates with in the soil for 1 cm when falls freely for 5 seconds. 2. Plastic limit The water content at which the soil begins to crumble when rolled into threads of specified size. The Plastic Limit, also known as the lower plastic limit, is the water content at which a soil changes from the plastic state to a semisolid state. Plastic Limit (PL or WP) ‑ the water content, in percent, of a soil at the boundary between the plastic and semi‑solid states. It is defined as “The moisture content at which the soil behaves like a plastic material is called plastic limit” It may also be defined as “The moisture content at which the soil changes from plastic state to semi solid state"

Determination of Liquid Limit and Plastic Limit of Soil
Determination of Liquid Limit and Plastic Limit of Soil

AS PER IS-( INDIAN STANDARD)

IS 2720-5 Methods of test for soils, Part 5: Determination of liquid and plastic limit