The sand is an inevitable material in construction which is used in almost every activity such as concrete, plastering, PCC, back-filling, earth embankment & many other works. The river sand naturally deposits in the riverbank, formed over many decades from the rock disintegrated and deposits on the river banks.
However, Due to the fast-growing urbanization, usage of river sand has rapidly increased over the past decade, but at the same time, that much of river sand is not available to supply. Over-excavation of sand also leads to drying of groundwater in and around the particular areas, and it is very harmful to the environment.
Due to the non-availability of river sand & environmental impact, the usage of Manufactured sand in the construction industry started increasing day by day. In Fact utilization of M sand in construction is appreciated because it is eco-friendly.
The Manufactured sand is manufactured by crushing the quarry stones into required grain size & after washing, grading the crushed cubical shape with rounded edges, it turned as a construction material. The hard rocks are blasted into medium-sized stones, and those stones are transported to the plant. Then the stones are washed and cleaned from dust & other impurities. The cleaned stones are placed into the primary crusher to crush the rocks into 40 mm aggregates. After that, the 40 mm aggregates are passed to the secondary crusher, which makes the 40 mm aggregates into 20 mm and below. Now the aggregates are screened and if found oversized aggregates again those aggregates are involved in crushing. After 1st stage screening, the aggregates are passed into a vertical shaft impactor to crush the aggregates into a cubical shape which is further reduced into below 4.75 mm. Again it is passed through VSI if found oversized particles after second stage screening. Finally, the sand was washed and above 150 microns particles automatically removed from the screening process and ready to use in construction.
Manufactured Sand Properties
Environmental Friendly – Since it has been manufactured artificially from the rock particles, it is less harmful to the environment compared to river sand.
Quality of material – The quality of the sand can be controlled during its manufacturing process so the particles are well balanced in quality.
Shape – The manufactured sand having a cubical shape & grounded edges.
Work-ability – Due to its shape & rough texture, it affects the work-ability of concrete.
Strength – The concrete strength is very high in manufactured sand compared to river sand used in concrete. Because it is manufactured from rock stones, it will have good compressive strength.
Quality of concrete – We mostly experience concrete bleeding & segregation, which will lead to concrete crazing while pouring the concrete & Shrinkage. Also, honeycomb formation happens after the concrete hardens. Those quality issues will not occur when using the manufactured sand in concrete.
Impurities – The manufactured sand does not contain the silt particles or other marine impurities like mica, silica, which affect the quality of concrete.
Manufactured sand with particle size above 4.75 mm is used for concrete work as per IS code 383. For plastering work in which particle sizes are less than 2.3 mm is used as per IS code 1542 , which is also called Plastering sand. For brick work manufactured sand which particle sizes are 3.5 mm is used as per IS code 2116.