Light Weight, Heavy Weight & Normal Weight Aggregates - Properties & Applications

Based on the bulk specific gravity of the aggregates, the classification is made as
  • Light Weight Aggregates
  • Normal Weight Aggregates
  • Heavy Weight Aggregates
These aggregates have a major role in the manufacture of concrete with varied properties. The field application of these aggregates will hence vary based on the properties of the aggregates showed in the concrete made.

Properties and Features of Light Weight Aggregate

  • The lightweight aggregates are natural or synthetic in nature. This will have the weight of 110kg/m3. 
  • The microstructure of LWA is porous and cellular in nature. This results in lightweight.
  • The absorption amount is higher. The concrete mix design with LWA is based on a modified approach.
  • Slump Loss is an issue faced during testing. Avoiding saturation of aggregates before batching can prevent this issue.
There are a variety of lightweight aggregate types. 
  1. Expanded shale, 
  2. Clay, slate 
  3. Foamed slag 
  4. Sintered fly ash 
  5. Exfoliated Vermiculite 
  6. Expanded perlite 
  7. Pumice 
  8. Expanded glass 
  9. Expanded polystyrene beads 
  10. Brick rubble 
  11. Crushed stone

Properties and Features of Heavyweight Aggregates

  • These aggregates can be either natural or synthetic with a weight greater than 2080kg/m3. This value can go up to 4485g/m3.
  • Used in areas where there is a need for a high mass-to-volume ratio
Types of Heavy Weight Aggregates
  1. Goethite 
  2. Limonite 
  3. Barite 
  4. Ilmenite
  5. Magnetite 
  6. Hematite 
  7. Ferrophosphorus 
  8. Steel

Properties and Features of Normal Weight Aggregates

Most common normal weight aggregates are:
  1. Sand
  2. Gravel
  3. Crushed Stone
Normal weight aggregate is the common type of aggregates with weight 2200 to 2400kg/m3.

Uses of Light Weight Aggregate

Lightweight aggregates have proven its efficiency in the construction of structures like

  1. Bridges
  2. Precast Industry
  3. Tunnel Construction
  4. Building Construction
  5. Offshore Construction
These structures will have less dead weight and have internal curing capacity as these particles have the water holding capacity to perform efficient hydration products in cement concrete.

Uses of Heavy Weight Aggregate

The heavyweight aggregates acquire high radiation and mechanical resistance which is to be used  in
  1. Radiation Shielding Units - Nuclear
  2. Structures near to Explosive Units
  3. Used for ballasting for pipelines - Offshore construction

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