Sand Types and Properties

Introduction 

Sand is a crucial component in construction, used for various purposes including concrete, mortar, plastering, and backfilling. Here's a breakdown of different types of sand, their properties, and step-by-step usage in construction:

1. River Sand

• Properties: Fine, round grains; very smooth; clean and free from salts.
• Usage: Ideal for concrete, plastering, and RCC structures.
• Step-by-Step:
1. Selection: Ensure the sand is clean and free from organic matter.
2. Sieving: Remove any impurities by sieving.
3. Mixing: Use appropriate proportions with cement and aggregates.

2. Pit Sand

• Properties: Coarse, angular grains; red-orange in color due to iron oxide; free from salts.
• Usage: Suitable for concreting, bricklaying, and filling purposes.
• Step-by-Step:
  1. Excavation: Extract sand from pits at a depth of 1-2 meters below the ground.
  2. Drying: Ensure the sand is dry before use.
  3. Screening: Remove impurities and ensure consistency in grain size.

3. Crushed Stone Sand

• Properties: Sharp, angular grains; manufactured by crushing stones; consistent particle size.
• Usage: Ideal for concrete production and as a fine aggregate in concrete.
• Step-by-Step:
  1. Crushing: Obtain sand by crushing hard stones.
  2. Grading: Ensure proper grading to match the requirements of the construction.
  3. Washing: Wash to remove any dust or clay particles.

4. M-Sand (Manufactured Sand)

• Properties: Processed from crushed rock; well-graded; cubical in shape; consistent quality.
• Usage: Replacement for river sand in concrete and plastering.
• Step-by-Step:
  1. Manufacturing: Produced by crushing rocks, quarry stones, or larger aggregates.
  2. Screening: Segregate and grade particles to meet construction standards.
  3. Quality Check: Ensure it meets IS (Indian Standard) specifications or relevant standards.

5. Sea Sand

• Properties: Fine, rounded grains; contains salts; potentially harmful for reinforced concrete.
• Usage: Limited use due to salt content, typically used for non-structural purposes after desalination.
• Step-by-Step:
  1. Desalination: Wash thoroughly to remove salts.
  2. Testing: Test for chloride content before use.
  3. Usage: Preferably for backfilling and non-reinforced concrete.

6. Desert Sand

• Properties: Fine and smooth; round grains; unsuitable for construction due to high silt content.
• Usage: Rarely used in conventional construction.
• Step-by-Step:
  1. Sourcing: Obtain from desert areas.
  2. Testing: Check for grain size and silt content.
  3. Mixing: Mix with other types of sand to improve suitability, if needed.

Step-by-Step Usage in Construction

1. Material Selection:

   • Choose the appropriate type of sand based on the specific requirements of the construction project.
   • Ensure the sand meets quality standards (clean, free of silt and organic matter).

2. Testing:

   • Conduct tests for particle size distribution, silt content, and other impurities.
   • Perform quality checks as per local standards (e.g., IS codes).

3. Preparation:

   • Sieve the sand to remove impurities and ensure uniformity.
   • Wash if necessary, especially for river sand and sea sand.

4. Proportioning:

   • Mix sand with cement and aggregates in the correct proportions.
   • Follow the mix design guidelines for concrete, mortar, or plaster.

5. Mixing:

   • Use mechanical mixers for large quantities to ensure uniform consistency.
   • For small projects, hand mixing can be done, ensuring thorough blending.

6. Application:

   • For concrete: Pour and compact the mixture in formworks.
   • For mortar: Apply between bricks or blocks for masonry.
   • For plastering: Spread evenly on walls and ceilings, ensuring a smooth finish.

7. Curing:

   • Allow the mixture to cure properly, maintaining moisture levels for the required time (typically 7-28 days for concrete).

8. Quality Control:

   • Regularly inspect the construction work for adherence to standards.
   • Conduct periodic tests on hardened concrete or plaster to ensure strength and durability.

By understanding the properties and appropriate usage of different types of sand, construction projects can achieve desired strength, durability, and finish.