The natural river sand was the cheapest resources of sand. However the excessive mining of rive bed to meet the increasing demand for sand in construction industry has lead to the ecological imbalance in the state. Now the sand available in the riverbed is very coarse and contains very high percentage of silt and clay. The silt and the clay presence in the sand reduce the strength of the concrete and holds dampness. The natural river sand is the product of sedimentation. mica, coal, fossils and other organic impurities are present in the river sand above certain percentage which make the sand useless for concrete work.
Acute shortage and high price for river sand has lead to the adulteration of sand with salty sea sand which has raised serious concern among builders. |