Natural or River sand are weathered and worn out particles of rocks and are of various grades or sizes depending upon the amount of wearing. Nowadays good sand is not readily available, it is transported from a long distance. Those resources are also exhausting very rapidly. So it is a need of the time to find some substitute to natural river sand.
The artificial sand produced by proper machines can be a better substitute for river sand. The sand must be of proper gradation (it should have particles from 150 microns to 4.75 mm in proper proportion).
When fine particles are in proper proportion, the sand will have fewer voids. The cement quantity required will be less. Such sand will be more economical. Demand for manufactured fine aggregates for making concrete is increasing day by day as river sand cannot meet the rising demand of the construction sector. Natural river sand takes millions of years to form and is not renewable.
Because of its limited supply, the cost of Natural River sand has skyrocketed and its consistent supply cannot be guaranteed. Under these circumstances use of M-Sand (manufactured sand) becomes inevitable.
River sand in many parts of the country is not graded properly and has excessive silt and organic impurities and these can be detrimental to the durability of steel in concrete whereas Msand(manufactured sand) has no silt or organic impurities.
Manufactured sand have been regularly used to make quality concrete for decades in India and abroad.
Typical Compressive Strength of Concrete: The following results show the behaviour of manufactured sand and riverbed sand when used in concrete:
- With using Riverbed Sand: (All proportions are by weight)
- Cement -50 Kg
- River Sand -75 Kg
- 20 mm- 75 Kg
- 12 mm -37.5 Kg
- Water -19 ltrs
- Compressive strength achieved after 7 – days curing …….44.1MPa
- With using MSand : (All proportion are by weight)
- Cement -50 Kg
- Artificial Sand – 70 Kg
- 20 mm – 80 Kg
- 12 mm – 35 Kg
- Water – 19 ltrs
- Compressive strength achieved after 7 -days curing …….46.8MPa
- Considering, the acute shortage of river sand, huge short coming on quality of river sand, high cost, greater impact on road damages and environmental effects, The Construction Industry shall start using the Msand(manufactured sand) to the full extent as an alternative, reduce the impacts on the environment by not using the river sand.
- The Local Authorities/PWD/ Govt, shall encourage the use of Manufactured sand in Public Construction Works, if possible, shall make mandatory to use Manufactured sand wherever available with immediate effect.
- The Govt. Shall come out with, Policy on Sand – encourage the industry people to set up more no of Sand crushing Units across the all Districts, States to meet the sand requirements of the Construction Industry.