Define and explain the index properties of the soils.

The properties of soil which helps to assess it's  engineering behaviour and which assist in determining its classification accurately are termed as index properties of soil.

The laboratory tests, which provide information on physical properties of soil are known as classification test and numerical result of such test are known as index properties. Index properties may be divided into two general types:

• Soil grain properties
• Soil aggregate properties

The soil grain properties are the properties of the individual particle of which the soil is composed and are independent in the manner of soil formation. These properties can be determined from distributed samples. Soil aggregate properties,on the other hand, depend on the structure and arrangement of the particles in the soil mass whereas the soil grain properties are commonly used for soil identification and classification. The the soil aggregate properties have a greater influence on the engin....

The properties of soil which helps to assess it's  engineering behaviour and which assist in determining its classification accurately are termed as index properties of soil.

The laboratory tests, which provide information on physical properties of soil are known as classification test and numerical result of such test are known as index properties. Index properties may be divided into two general types:

• Soil grain properties
• Soil aggregate properties

The soil grain properties are the properties of the individual particle of which the soil is composed and are independent in the manner of soil formation. These properties can be determined from distributed samples. Soil aggregate properties,on the other hand, depend on the structure and arrangement of the particles in the soil mass whereas the soil grain properties are commonly used for soil identification and classification. The the soil aggregate properties have a greater influence on the engineering behaviour of soil mass some of soil grain  properties are:

• Particle size
• Grain shape
• Mineralogical composition

Some of soil aggregate properties are:

• Relative density
• Consistency
• Unconfined compressive strength
• Thixotropy
• Sensitivity and activity