The natural river sand was the cheapest resources of sand. However, the excessive mining of rive bed to meet the increasing demand for sand in the construction industry has lead to the ecological imbalance in the state. Now the sand available in the riverbed is very coarse and contains a very high percentage of silt and clay.
The silt and the clay presence in the sand reduce the strength of the concrete and hold dampness. The natural river sand is the product of sedimentation. mica, coal, fossils and other organic impurities are present in the river sand above a certain percentage which makes the sand useless for concrete work.
|Process||Manufactured in a factory.||Naturally available on river banks.|
|Shape||Angular and has a rougher texture. Angular aggregates demand more water. Water demand can be compensated with cement content.||Smoother texture with better shape. Demands less water.|
|Moisture Content||Moisture is available only in water washed M Sand.||Moisture is trapped in between the particles which are good for concrete purposes.|
|Concrete Strength||Higher concrete strength compared to river sand used for concreting.||Lesser concrete compared to M Sand|
|Silt Content||Zero silt||Minimum permissible silt content is 3%. Anything more than 3% is harmful to concrete durability. We can expect 5 – 20% slit content in medium quality river sand.|
|Over-Sized Materials||0%. Since it is artificially manufactured.||1 – 6% of minimum oversized materials can be expected. Like pebble stones.|
|Marine Products||0%||1 – 2% like seashells, tree barks etc|
|Eco-Friendly||Though M Sand uses natural coarse aggregates to form, it causes less damage to the environment as compared to river sand.||Harmful to the environment. Eco imbalances, reduce groundwater level and rivers water gets dried up.|
|Price||M Sand price ranges from Rs.35 – Rs.45 per cubic feet||River sand price ranges from Rs 60 – 80 per cubic feet|
|Adulteration||The probability of adulteration is less.||High probability of adulteration since filtered sand (a type of pre-washed sand which contains high silt contents) are mixed together. As a rule, the supply shortage always brings adulterer products to the market.|
|Applications||Highly recommended for RCC purposes and brick/ block works.||Recommended for RCC, plastering and brick/ blockwork.|
|Quality||Better quality control since manufactured in a controlled environment.||No control over quality since it is naturally occurring. Same river bed sand can have differences in silt contents.|
|Particle passing 75 micron||Up to 15% (IS: 383 – 1970)||Up to 3% (IS:383 – 1970)|