All about Sand and its use as a construction material.

Sand has been nature’s contribution to human development. Any housing that is seen, any concrete bridge that is walked on, any steps that are climbed carry these natural blessings in abundance. Whether in the manufacture of bricks or as a base material for preparing concrete, sand is there everywhere.

For this purpose mining through sand blocks has been taking place in active collaboration between private groups and government. Like the Abhinna group, which engages in mining through Sand Blocks in West Bengal – in areas like Uttar Dinajpur, Birbhum, Purba Paschim Burdwan, Bankura, Medinipur, Purulia, Malda and Jalpaiguri District.


Here we get to know about this bountiful gift of nature :

 About Sand : What we call sand in common terms is actually a mixture of fragmented particles of decomposed rocks, shells, corals etc. Sand had been a result of fragmentation over the years. In terms of size, it is finer than gravel and coarser than silt. Though sand is a mixture of many materials,  the most common constituents of sand is silica.  Another important constituent of sand is calcium carbonate. The percentage of composition of the constituents varies from place to place, depending on natural surroundings.


Uses of Sand in Construction :  Though there have been different uses of sand – from manufacture of glasses to ingredient for polishing tools, it for construction industry that sand is most popularly used. The popularity of sand as a base material for concrete was popularized during World War I when there grew an abundant need to construct paved roads. This popularity grew through the 1920s. Then came in the late 1940s and early 1950s – an era which witnessed the boom in housing. Over the years as the concept of apartments came in, the need for sand as the base material for concrete grew.

In concrete sand is mixed with gravel, cement and water and made into a slurry. This slurry when hardened forms a rock-solid concrete structure which provides the base strength to buildings. The coarse, angular structure and the strength of the sand provides the inter molecular space for adequate binding, as well as provides strength to the concrete structure.


Different Types of natural sand that obtained :

1) Pit Sand : Pit sands are coarse sand. This type of sand  are obtained from digging deep pits where there is an abundance of supply. This is generally  red-orange in color. The coarse and angular shape of the particles makes it usable in concrete.

2) River Sand : Desert sand is obtained from river bed. Compared to pit sand it is of finer quality. It is whitish grey in color. The grains are more fine and rounded due to mutual attrition. This makes it of a very fine quality. It is much used in construction especially for plastering.

3) Sea Sand : It is obtained from sea shores. The grain is brown and rounded. However sea sand is not much used as construction material because the rounded structure makes it less resistant to molecular rearrangement.  Moreover sea sand contains salts which erodes the plastered surface and causes seepage in the long run.

4) Desert Sand : This is the type of sand one would find in the desert region formed by the erosion of rock for many million years.  Desert sand is however not suitable for construction purposes.



Responsible Sand Mining : Looking at the enormous need of sand for construction purposes, sand mining becomes an inevitable reality. Sand mining is done either through sand pits or extraction from river beds. However rampant mining is always prohibited and a few groups like the Abhinna Group- a mining company in kolkata has taken up the cause of ‘responsible sand mining’ where sand mining takes place with extreme caution and care. Extreme caution is taken to maintain the natural balance and without unending disturbance to natural topography. By this the sand is obtained but keeping the environment aspect in mind.