M-SAND
What does M-Sand mean?
M-Sand stands for Manufactured Sand. M-sand is crushed aggregates produced from hard granite stone
which is cubically shaped with grounded edges, washed and graded with consistency to be used as a
substitute of river sand.
Definition: A fine aggregate that is produced by crushing stone, gravel, or slag.
Use of Manufactured Sand in Concrete and Construction an Alternate to River Sand
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. Now-a-days 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 to 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 construction
sector. Natural river sand takes millions of years to form and is not repleneshible.
Because of its limited supply, the cost of Natural River sand has sky rocketed and its consistent supply
cannot be guaranteed. Under this circumstances use of 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 durability of steel in concrete whereas manufactured sand has
no silt or organic impurities
Manufactured sand River sand
However, many people in India have doubts about quality of concrete / mortars when manufactured or
artificial sand are used. Manufactured sand has been regularly used to make quality concrete for
decades in India and abroad.
PUNE - MUMBAI EXPRESSWAY WAS COMPLETELY BUILT USING
ARTIFICIAL/MANUFACTURED SAND.
ISSUES WITH MANUFACTURED SAND
1. The Civil engineers, Architects, Builders, and Contractors agree that the river sand, which is
available today, is deficient in many respects. It does content very high silt fine particles (as in case of
Filter sand).
2. Presence of other impurities such as coal, bones, shells, mica and silt etc makes it inferior for the
use in cement concrete. The decay of these materials, due to weathering effect, shortens the life of
the concrete.
3. Now-a-days, the Government have put ban on lifting sand from River bed.
4. Transportation of sand damages the roads.
5. Removing sand from river bed impact the environment, as water table goes deeper & ultimately
dry.
General Requirements of Manufactured Sand
1. All the sand particles should have higher crushing strength.
2. The surface texture of the particles should be smooth.
3. The edges of the particles should be grounded.
4. The ratio of fines below 600 microns in sand should not be less than 30%.
5. There should not be any organic impurities
6. Silt in sand should not be more than 2%, for crushed sand.
7. In manufactured sand the permissible limit of fines below 75 microns shall not exceed 15%.
Crushing, Screening, and Washing
Manufacturing of Sand process involves three stages, crushing of stones in to aggregates by VSI, then
fed to Rotopactor to crush aggregates into sand to required grain sizes (as fines). Screening is done to
eliminate dust particles and Washing of sand eliminates very fine particles present within. The end
product will satisfy all the requirements of IS:383 and can be used in Concrete & construction. The VSI
Plants are available capacity up-to 400Ton Per Hour (TPH).
IS Code Provisions
BIS Guidelines IS: 383-1970 for selection and testing of Coarse and Fine aggregates available.
Generally, Sand is classified as Zone I, Zone II, Zone III and Zone IV (i.e. Coarser to Finer). There is
sieve designation for each zone. Gradation is made in accord with the usage of the sand. There are
testing sieves, consists of 4.75mm, 2.36mm, 1.183mm, 600microns, 300 microns, 150 microns and a pan
Typical Sieve analysis: Comparison of River & Manufactured Sand
% of passing % of passing Zone II
IS Sieve
(River Sand) (Manufactured Sand ) (As per IS:383)
4.75mm 100 100 90-100
2.36mm 99.7 90.7 75-100
1.18mm 89 66.2 55-90
600micron 60.9 39.8 35-59
300micron 17.7 25.5 8-30
150micron 3.1 9.9 0-20
75micron Max 3 Max 15 Max 15
Zone II Zone II
The gradation of manufactured sand can be controlled at crushing plant
Technical specification – comparison between Manufactured and River sand
Sl Manufactured
Property River sand Remarks
No sand
1 Shape Spherical particle Cubical particle Good
2 Gradation Cannot be controlled Can be controlled
Presence of silt shall Limit 3% for
Presence of dust
Particle passing be less than 3% uncrushed & limit
3 particle shall be
75micron (IS:383- 15% for crushed
less than 15%
1970)reaffirmed 2007 sand
Present (Retard the Limit of 5% for
Silt and Organic
4 setting & Compressive Absent Uncrushed & 2%
impurities
Strength) for Crushed sand
5 Specific gravity 2.3 – 2.7 2.5 – 2.9 May vary
6 Water absorption 1.5 - 3% 2 – 4% Limit 2%
Ability to hold
7 Up-to 7% Up-to 10%
surface moisture
Recommends
Zone II and III Zone II
8 Grading zone(FM) Zone II for Mass
FM 2.2 -2.8 FM 2.6 – 3.0
Concrete
Soundness(Sodiu
m sulphate-ss &
Relatively less sound Relatively sound Limit 10% ss and
9 Magnesium
(Ex. >5) (Ex. <5) 15% ms
sulphate -ms) (5
cycles)
Alkali Silica Limit
10 0.002 -0.01 0.001- 0.008
Reactivity 0.1%expansio
Behavior of Manufactured & River Sand when used in Concrete
Sl No Property River sand Manufacture Remedies
d sand
Control of fines & apply water
Workability & Good & Good Less & Less
1 absorption correction, use of
its retention retention retention
plasticisers
Comparatively Apply water absorption correction,
2 Setting Normal
faster use retarders
Compressive Marginally
3 Normal As shown above
strength higher
4 Permeability Poor Very poor
Tend to Early curing & protection of fresh
5 Cracks Nil
surface crack concrete
Cost comparison of Manufactured and River sand
Artificial
Sl no Location- Bangalore City River sand Remarks
sand
Rs 1100 per Rs 600 per
1 Market rate 50% Cheaper
MT MT
Saving of Rs 350-
2 In Concrete - Rs per Cum Rs 770 – 880 Rs 420 – 480
400 per cum
3 In Mortar(1:5) for 100kgs Rs 198 Rs 156 20% less
Typical Compressive Strength of Concrete: The following results show the behavior of manufactured
sand and riverbed sand when used in concrete:
With using Riverbed Sand: (All Compressive strength achieved after 7 -
proportions are by weight) days curing …….44.1MPa
Cement -50 Kg Cement -50 Kg
River Sand -75 Kg Artificial Sand - 70 Kg
Agg. 20 mm- 75 Kg Agg. 20 mm - 80 Kg
Agg. 12 mm -37.5 Kg Agg. 12 mm - 35 Kg
Water -19 ltrs Water - 19 ltrs
With using Artificial Sand: (All proportion are by weight): Compressive strength achieved after 7 -days
curing …….46.8MPa
Vastu Aspects of River sand
Now-a-days, Vastu Shastra is more popular, consults Vastu by many people while constructing a house.
As per Vastu Shastra, the building material must be free from traces of human or animal body. The river
sand contains bones of human beings and animals. The shells are also a kind of bone. It is not easy to
take out all such things present in the river sand. Hence, the best solution for this is to use
artificial/crushed sand of good quality for human well being.
Environmental Impact
The River sand lifting from river bed, impact the environment in many ways:
Due to digging of the sand from river bed reduces the water head, so less percolation of rain
water in ground, which result in lower ground water level.
The roots of the tree may not be able to get water.
The rainwater flowing in the river contents more impurities.
Erosion of nearby land due to excess sand lifting
Disturbance due to digging for sand & lifting, Destroys the flora & fauna in surrounding areas
The connecting village roads will get badly damaged due to over- loading of trucks, hence, roads
become problem to road users and also become accidents prone
Diminishing of Natural Rivers or river beds, not available for future generations.
Conclusion
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 manufactured sand to full extent as alternative, reduce the impacts on
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.
M-Sand thrown up as an alternative to river sand
With river sand becoming scarce and being sold at a premium following the Madras High Court
restrictions on sand mining in rivers Cauvery and Tamirabharani, the need to find an alternative concrete
aggregate material to river sand in construction works has assumed greater importance now .
Engineers and specialists have come out with their own ideas to minimise the use of river sand and use
recent innovations such as M-Sand (manufactured sand), robot silica or sand, stone crusher dust, treated
and sieved silt removed from reservoirs as well as dams besides sand from other water bodies.
The most preferred alternative to river sand is the M-Sand got through processing the blue metal quarry
dust. Fine and uniform granulation of quarry dust by floating it through pressurised water shower leading
to reduction of impurities gives us M-Sand.
The production of robot silica or sand, got through another method of processing gravel and soil by
cleansing the material of clay and other impurities, providing uniform granulation to the processed
material, is at a nascent stage and might take some more years to gain wider acceptability.
But both M-Sand and robot sand, due to their processing, is dearer when compared to river sand during
normal availability periods in regular markets. Industry watchers point out that the presence of more than
500 blue metal crushers in the Karur-Tirupur-Coimbatore-Salem belt would easily facilitate production of
M-Sand in huge quantities to meet public requirements of the region.
However, structural engineers and reputed builders whom The Hindu spoke to showed thumbs down to
use of M-Sand and robot sand in concrete applications citing test failures for load bearing strength and
durability for any mixture classification.
Particularly for concrete roof only river sand must be used to achieve the general required compression
strength of 28-30 Kilogram Newton per square mm, they say adding any admixture aggregate containing
quarry dust and M-sand might just fail to pass muster.
Then there are experts who propound the guided exploitation of silt gathered at the dam and reservoir
sites across the State and remaining uncleared for decades.
“The silt at the major dams could be dredged, suitably sieved and processed to find applications instead
of river sand. Thereby the pressure on river sand might come down drastically while dams and reservoirs
could regain their lost volume and farmers and public might get innumerable benefits. All that could
happen if the State government studies the situation and directs removal of silt of all dams and
reservoirs,’’ notes former PWD Special Chief Engineer A. Veerappan.
The State government and the PWD need not spend a single pie on the effort and contractors could be
engaged for dredging the dam sites and clearing the silt which simultaneously increases their dead
storage capacity, he observes.
There are hundreds of PWD tanks and ponds besides thousands of water bodies under the control of the
panchayats across the State that have gradually got shrunk due to accumulation of silt over the years.
They could be desilted and while the top layer of the removed silt could used as manure in agricultural
applications the bottom strata could be used for filling works, retired PWD Superintending Engineer
S.Natarajan opines.
However, structural engineers and builders point out that sand gradation must conform to BIS 383 Table
15 and BIS 10232 standards apart from which the sieved sand must conform to Zone II classification for
concrete works.
There should not be any deleterious material covering sand granule for more than three per cent, passing
the 75 micron sieve analysis process, they pinpoint when speaking about alternatives to river sand in
concrete and plaster applications, be it for private or public use.
Sieved silt collected from ponds as well as dam sites, and conforming to such standards, could be used
instead of river sand for mortar and plastering applications only in select cases under specialized care,
some others say.
It has been proved that filter sand is not fit for construction purposes and the state government has
banned its use in Karnataka. Filter sand might lead to development of cracks in structures, thus reducing
its compressive strength and life. Production of filter sand has been adversely affecting the fertility of
agriculture land. Filter sand isn't good for the environment either. The government had ordered that
violators and illegal operators involved in sand mining and filter sand trade will be jailed and have a hefty
fine imposed on them. Cases will be booked under the Anti-Goonda Act against them.
What are the ill-effects of filter sand on buildings?
Filter sand is the term used for the material taken from the bottom of the lake or manmade trough like
ponds. This is not sand but washed mud with high levels of silt, mud and other chemicals, which has
corrosive effects. Silt and mud are enemies of concrete. It means that we need to add more cement to
increase the strength of the concrete and the danger is that it will lead to cracks in structure reducing the
compressive strength and life of the structures.
What is the alternative?
Manufactured sand is the alternative for river sand. Manufactured sand can now be produced in a stone
crushing plant by implementing Vertical Shaft Impactors (VSI) and washing plant like the Other. This sand
is produced from stones which are used for aggregates and the quality is consistent and better than river
sand. River sand is highly adulterated with filter sand these days.
Is there a growing demand for manufactured sand?
The concept has been already accepted and well-received in Maharashtra and Kerala. Recently, Tamil
Nadu and Karnataka Governments have also allowed the use of manufactured sand in all government
contracts.
What is Bangalore's requirement of sand per day?
The demand for sand (river and manufactured sand) is estimated to be around 40,000 tons per day.
Watch:
https://www.youtube.com/watch?v=7pQW_vt_Ueo
