Fine aggregate plays a critical role in concrete as it fills the voids between the coarse aggregates and binds the cement paste together. It also affects the workability, strength, durability and the appearance of the finished product.
Fine Aggregate in Construction - Types and Properties
Fine aggregate is known as sand which size ranges from 0.075 mm to 4.75 mm. It is the material used in concrete production, brick works, wall plastering, filling etc. The examples of fine aggregates are natural fine aggregate, river fine aggregate (sand), manufactured fine aggregate and crushed stone fine aggregate etc.
The quality of fine aggregate is important as it can affect the performance of the concrete. Good quality fine aggregate should be clean, free of impurities and have a consistent particle size distribution. It should also have the right shape and texture to ensure good bonding with the cement paste.
Types of Fine Aggregate
There are various types of fine aggregate (examples) used in construction and they can be classified based on their source, shape, size and texture. Here are some of the common types of fine aggregate:
Natural Sand or Natural Fine Aggregate
Natural sand is obtained from river beds or pits and is the most commonly used type of fine aggregate. It is available in different sizes and shapes and can vary in color and texture based on the source.
M-Sand or Manufactured Fine Aggregate
Manufactured sand is a type of fine aggregate that is produced by crushing rocks, quarry stones, or larger aggregates. It is used as a substitute for natural sand and is available in different grades based on the size and shape of the particles.
Crushed Fine Aggregate
Crushed sand is a type of manufactured sand that is produced by crushing larger rocks and aggregates. It is available in different sizes and shapes and is commonly used in concrete and other construction applications.
Glass Fine Aggregate
Glass sand is a type of recycled glass that is crushed and used as a fine aggregate in construction applications. It is commonly used in decorative applications like landscaping and terrazzo flooring.
Pozzolanic Fine Aggregate
Pozzolanic sand is a type of fine aggregate that is produced from volcanic ash or other natural materials that contain pozzolanic properties. It is commonly used in concrete applications to enhance the strength and durability of the concrete.
Tests Performed on Fine Aggregate (Properties)
The following tests are generally performed to check the quality of fine aggregate:
Sieve Analysis or Grain Size Analysis of Sand
A test to measure the average grain size of a sample of sand, typically using a microscope or a laser particle size analyzer.
Specific Gravity Test of Sand
A test to determine the density and porosity of a sample of sand which is important for understanding its strength and compaction properties.
Shape and Surface Texture Test
A test to examine the physical characteristics of a sample of sand such as the shape of the grains, the roughness of the surface, and the presence of any coatings or impurities.
Bulk Density and Dry Density Test
Bulk density and dry density test is performed to check the mass per unit volume of sand. It can be use in various purposes in construction.
Bulking of Sand
The bulking of sand is tested to know the variation of volume of sand when interact with water.
Organic Impurities Test on Sand
A test to determine the presence of any organic materials like vegetation, leaves or other plant material in a sample of sand.
Moisture Content or Water Absorption Test
A test to determine the amount of water present in a sample of sand.
Silt Content Test
In this the percentage of silt is determined present in the sand sample. Silt content having much impact on the properties of sand.
Alkali aggregate Reactivity Test
A test to determine the behavior of a sample of sand when subjected to compaction pressure.
Total Deleterious Material Test
This test is performed to know the availability of minerals finer than 75 microns, coal, lignite and clay lumps.
