Posted By:Infra Bazaar
There is a spectacular growth of the construction industry and every river in India has made a major contribution to it through the supply of sand today. The mining of sand which is an essential part of construction has often been in the news. Sand is necessary for the river, but also plays a great role the in construction industry. The great volume of sand is exported from stream beds and coastal areas. Sand is the soil of the river, which provides and sustains all life that exists in the rivers. Along with gravel, it forms part of the hyporheic zone, between the surface water of the river and the groundwater beneath. Sand and gravel are used extensively in the preparation of concrete, and for each ton of cement, the building industry needs about seven times more tons of sand and gravel. Sand and gravel are mined across the world and account for the large volume of solid material extracted globally. It is the highest volume of raw material used on earth after water. It is 70-80% of the 50 billion tons material is mined every year. It has been gradually formed by erosive processes over thousands of years. Today they are being extracted at a rate far greater than what is renewed.
Sand is being mined exponentially, as a result of rapid economic growth in Asia and the resulting boom in construction. Sand mining generates extra vehicle traffic, which gives a boost to the economy and produces the material required for the urbanization that is the dream of many people all around the world. it is necessary for the long-term survival of a river. The humungous scale of sand and gravel extraction and the number of hydroelectricity projects coming up will have a great impact on the way of living of people. Sand can Harbor unique invertebrate fauna and micro-organisms such as fungi and microbes and can filter the water, due to its physical, chemical and biological conditions. Sand definitely contributes to the best in infrastructure. Sand is extracted inland quarries and riverbeds, but of late there is a shift to marine and coastal areas due to the decline of inland resources. River and marine aggregates are now the main sources for building and land reclamation.
Sand Mining and dredging activities, have to be properly planned to oversee the overburden and damage owing to its ecological impacts. It needs a national effort to develop an ecologically safe, cost-effective, technique for all projects. NGT reaffirmed the Supreme Court’s order last year which banned mining of sand, without environmental clearance from the Union Ministry of Environment and Forests. Care should be taken of this aspect also.
Substitutes for sand are also available. Quarry dust could be used to replace sand in concrete structures. The replacement of sand by incinerator ash exhibits higher compressive strength. Desert sand can be used if it is mixed with other materials.
Several investigations are being done to increase the effectivity of sand use. It is composed of individual grains and has a mechanical functioning when it comes into contact with other agents.