Soil

The hydrometer method of grain size analysis calculates the physical proportions of the soil particles based on their settling rates in an aqueous solution and identifies it as sand clay or slit.

Specific gravity of soil solids is defined as the weight of soil solids to weight of equal volume of water.

The dry density of compacted soil is a measure of the amount of compaction achieved during construction. Knowing the field density and moisture content, the dry density can be calculated.The test involves hammering a cylindrical core cutter of known mass and volume into the soil mass, excavating it and calculating the mass of the soil contained in the cylinder.

Determination of field density using the sand replacement method involves three steps. The first step involves calibration of a sand-pouring cylinder. The soil density is measured in the second step and then the water content and dry density is measured in the third step.

Liquid Limit is measured by spreading a portion of the soil sample in the brass cup of a liquid limit machine and dividing it using a grooving tool. Plastic Limit is determined by repeatedly remolding a small ball of moist plastic soil and manually rolling it out into a 1/8in thread. Shrinkage Limit is performed by molding a soil pat of moist test material into a special shrinkage dish. The dish and soil are oven-dried and weighed, then the volume of the specimen is determined by water displacement.

A Modified Proctor test is conducted by placing soil in a standard mold and compacted with a standard ram. Compaction of soil is done by dropping a standard ram 25 times for each layer of soil from a standard distance. After compaction of all five layers, the weight of the soil is obtained and the dry density and moisture content is calculated.

Free Swell Index is the increase in volume of a soil, without any external constraints, on submergence in water.

Sieve analysis is a method that is used to determine the grain size distribution of soils that are greater than 0.075 mm in diameter. It is usually performed for sand and gravel.

The california bearing ratio test is penetration test meant for the evaluation of subgrade strength of roads and pavements and of the materials used in its construction.

Removing soil moisture by oven-drying a soil sample until the weight remains constant. The moisture content(%) is calculated from the sample weight before and after drying.