fbpx

Crushed Sand vs. Natural Sand: Make the Right Choice!

Sand is one of the vital ingredients in construction works. A huge amount of concrete is consumed in construction works.

About 35 % volume of concrete is comprised of sand. Generally, cement and coarse aggregates are factory made products and their quality and standards can be easily controlled and maintained. The sand is usually excavated from river beds or river bank by digging. The natural sand deposits are getting depleted by continuous digging causing damage to the environment in many ways. As the supply of suitable natural sand near the point of consumption is becoming exhausted, the shortage of good natural sand for concrete production is facing challenges. The construction industry has a huge need to solve this challenge. This is also resulting in poor qualities of sand, particularly containing silt. They need to solve this challenge by using crushed sand in construction works. It is a better substitute for natural sand considering increasing demand of sand in construction industry. Hence, here we give you a brief comparison of these materials to help you make the correct choice.

Crushed Sand vs Natural Sand

01. Source

Crushed Sand (Manufactured Sand)

  • The source of Crushed sand is a quarry. It is manufactured by Crushing rocks, quarry stones or larger aggregate pieces into sand size particles in a factory or quarry.

Natural Sand

  • It is naturally available and extracted from the river banks or river beds.

02. Property

(a) Shape

Crushed Sand (Manufactured Sand)

  • The shape of Crushed sand is cubical and angular and has a rough texture and hence better for concrete.

Natural Sand

  • The shape of natural sand is rounded and has a smooth surface.

(b) Moisture Content

Crushed Sand (Manufactured Sand)

  • No moisture content.

Natural Sand

  • Moisture is generally present in between the particles. Hence, effects the assumptions of concrete mix design and quality of concrete.

(c) Concrete Strength

Crushed Sand (Manufactured Sand)

  • The compressive strength as well as the flexural strength of concrete made from Crushed sand are higher than natural sand.

Natural Sand

  • The compressive strength as well as the flexural strength of concrete made from natural sand are lower than Crushed sand.

(d) Silt Content

Crushed Sand (Manufactured Sand)

  • It does not contain silt as it manufacturing by crushing aggregates. However, if screen is not proper sometimes it may contain some dust.

Natural Sand

  • It contains silt as river water contains it due to erosion of soil in its catchment area. Hence it needs washing on site.

(e) Over Sized Materials

Crushed Sand (Manufactured Sand)

  • It is artificially manufactured so there are no oversized materials.

Natural Sand

  • Oversized materials are expected in natural sand and hence needs screening on site.

(f) Marine Products

Crushed Sand (Manufactured Sand)

  • It does not contain any marine products.

Natural Sand

  • It may contain marine products such as grass, algae, clay lumps, bones, shells, mica etc. which are harmful to properties of concrete.

(g) Eco Friendly

Crushed Sand (Manufactured Sand)

  • It causes less damage to the environment as compared to natural sand.

Natural Sand

  • It is harmful to the environment. It reduces the ground water level and rivers water gets dried up.

(h) Adulteration

Crushed Sand (Manufactured Sand)

  • Less adulteration.

Natural Sand

  • It has high probability of adulteration because of acute shortage. River sand adulteration with saline sea sand is common in coastal areas.

03. Applications

Crushed Sand (Manufactured Sand)

  • It is highly recommended for RCC and brick/ block works.

Natural Sand

  • It is recommended for RCC, plastering and Brick/Block works

04. Quality

Crushed Sand (Manufactured Sand)

  • Better quality as compared to natural sand because it is manufactured in a controlled environment.

Natural Sand

  • The quality of natural sand deferrers though they may be from the same river bed.

05. Grading Zone

Crushed Sand (Manufactured Sand)

  • Manufactured to conform to zone II.

Natural Sand

  • Mostly conforms to zone II and zone III

06. Bulk Density

Crushed Sand (Manufactured Sand)

  • 1.75 Kg/m3

Natural Sand

  • 1.44 Kg/m3

07. Specific Gravity

Crushed Sand (Manufactured Sand)

  • Approximate 2.73 (It will depend on parent rock.)

Natural Sand

  • Approximate 2.65 (It will depend on rocks in catchment area.)

08.  Advantages

Crushed Sand (Manufactured Sand)

  • It is an eco-friendly material.
  • It gives higher durability and strength to concrete by overcoming deficiencies like segregation, bleeding, honeycombing, voids and capillary.
  • Uniformly graded aggregates are available.
  • Higher cohesion and compressive strength.
  • Better concrete/ mortar quality.
  • The slump is less.
  • Water retentivity of mortar is less.
  • No need to bulkage correction during mix design.

Natural Sand

  • It is naturally available.

09.  Disadvantages

Crushed Sand (Manufactured Sand)

  • Crushed sand can be of coarser and angular texture. This can lead to more water and cement requirement to achieve the expected workability.
  • Crushed sand contains a larger amount of micro- fine particles. This can affect the strength of concrete.

Natural Sand

  • The presence of silt and clay in the sand reduces the setting time of cement and make concrete and mortar weak and holds the dampness.
  • The requirement of cement is more.
  • Water table level get reduced due to dragging of the sand from the river and the roots of the tree may not be able to get water.
  • In the absence of sand in river, water gets evaporated due to direct sun light.
  • The slump is more.
  • Water retentivity of mortar is more.
  • Bulkage correction is required during mix design.
  • Costly where river are far away.

10. Cost

  • It will depend on distance of site from source like river or quarry. But ultimately increased availability of crushed sand plants (it needs special crusher), it will become cheaper as natural river sand. Sand is ultimately scarce material.

Special Comments

It is recommended to use crushed sand. It is an economic and ecological alternative to natural sand. Crushed sand possesses properties similar to that of river and is a more sustainable construction material. Scientifically use of crushed sand will provide a long-term solution to construction industry to overcome shortage of river sand.

Also Read: Size Wise Classification of Aggregates

Author

Mentor

--

Editor

--

Best Home Designs

Showcase your Best Designs

Material Exhibition

Explore the world of materials.
Exhibit your Brands/Products.

More From Topics

Use below filters for find specific topics