Classification of Sands

 The classifications of sand are; Fine sand, medium sand, and coarse sand.

• Fine sand = 0.075 to 0.425 MM
• Medium sand = 0.425 to 2 MM
• Coarse Sand = 2.0 to 4.75 MM

Fine sand

Fine sand should consist of natural sands or crushed stone sands. It should be hard, durable, clean, and be free from organic matter, etc. Fine sand should not contain any appreciable amount of clay balls and harmful impurities such as alkalis, salts, coal, and decayed vegetation etc, the content of the silt should not exceed 4 %.

 Various type of sand:

Classification of sands talks about various type of sand, like; Pit sand, river sand, and sea sand.

Pit sand (coarse sand)

It is obtained by forming pits into soil from quarries, it consist of sharp angular grain which is free from salt. It is coarse sand, reddish yellow in color, and is used in concreting normally.

River sand

This is obtained from the bank of rivers. It usually consists of fine rounded grains. It is normally white and grayish in color. It is widely used for plastering and is available in clean condition.

Sea sand         

This is obtained from sea shores. It is brown in color and it also has the fine rounded grain. As it is obtained from sea it contains salt, which is used in attracting moisture from atmosphere. Such absorption causes dampness and disintegration of work. It is generally not used for engineering purpose due to its retards setting action of cement. It is normally used for non structural purposes.

Sands for construction works:

For different construction of works requires different standards of sands.

For brick works: It requires the finest module of fine sand should be 1.2 to 1.5 and silt content should not be more than 4 %.

For plastering works: It requires the finest module of fine sand, it should not be less than 1.5 and silt content should not be more than 4 %.

For Concerting Works: The coarse sand should be used with the finest modulus 2.5 to 3.5 and silt contents should not be more than 4%.

Note

The blending of sand should be done by adding more coarse sand to achieve the required finest module, if the above quality of sand is not readily available due to any kind of reasons. For obtaining more strength in construction work, washed sand should be used at the site. These are the classifications of sands.

Questions:

• Mention types of sand?
• Explain Fine sand?