Sand is an important building material. It abundantly occurs in nature and is formed by the decomposition of rocks. Sand particles consist of small grains of silica (SiO2). It forms a major ingredient in concrete, lime mortar, cement mortar, etc.
2.1 NATURAL SOURCES OF SAND
Sand is formed by the weathering of rocks. Based on the natural sources from which sand is obtained, it is classified as follows:
- Pit sand
- River sand
- Sea sand
2.1.1 Pit sand
This sand is obtained by forming pits in soils. It is excavated from a depth of about 1-2 m from the ground level. This sand is found as deposits in soil and it consists of sharp angular grains, which are free from salts. It serves as an excellent material for mortar or concrete work. ...