- It is a form of silica, which may be siliceous, argillaceous according to the composition. It is formed by decomposition of sandstone due to various weathering effects.
- Sand obtained from pits, shores, river bed, the seabed is known as natural sand.
- Sand obtained from crushing of stones is known as artificial sand.
- Sand is mostly used as inter-material in mortar and concrete. Sand may be divided into two categories depending upon its fineness and passing through an Indian standard sieve of size 4.75mm is termed as fine sand and retaining on its known as coarse sand.
- Sand increase the volume of mortar, thereby making economical and also prevents excessive shrinkage of cement paste, thereby avoiding crakes during setting. Fine sand occupies the voids in coarse aggregates.
- This helps in making concrete a solid, waterproof material. Very fine sand and very coarse sand is objecting in a sense that, fine sand is uneconomical whereas coarse sand gives harsh, less workable mix.