What is particle size distribution of coarse aggregate?

Mechanical sieving is the most commonly used method to determine the grading, i.e., particle size distribution, of an aggregate. Basically, the sieving operation attempts to divide a sample of aggregate into fractions, each consisting of particles within specific size limits.

How do you determine the size of an aggregate?

The most popular field test to measure the quality of aggregate is the sieve test. It is not possible to measure shape characteristic and other parameters by sieve analysis. Therefore, it is essential to develop rapid assessment techniques for quality control of aggregate.

Why is it important to determine the size distribution of aggregates?

Particle size distribution is important for understanding the physical and chemical properties of a material, making it a great cleanliness and quality assurance tool for manufacturers across a variety of industries.

Are sieves fine aggregates?

Indian standard test sieves, weighing balance ,sieve shaker etc . Size of sieves to be used: For fine aggregate- 4.75mm, 2.36mm, 1.18mm, 600 microns, 300 microns, 150 microns. For coarse aggregate-25mm,20mm 12.5mm, 10mm, 4.75mm.

How do you find the maximum size of coarse aggregate?

Aggregate Size Nominal Maximum Size: The smallest sieve opening through which the entire amount of aggregate is permitted to pass. coarse aggregate MUST pass the 1.5” sieve but 95 – 100% MAY pass the 1” sieve, therefore # 57 aggregate is considered to have a Maximum size of 1.5” and an Nominal Maximum size of 1”.

How shape and size affect the aggregate properties?

The shape and texture of aggregate affects the properties of fresh concrete more than hardened concrete. Crushed stone produces much more angular and elongated aggregates, which have a higher surface-to-volume ratio, better bond characteristics but require more cement paste to produce a workable mixture.

What are the general size characteristics of aggregates?

Although some variation in aggregate properties is expected, characteristics that are considered include:

• grading.
• durability.
• particle shape and surface texture.
• abrasion and skid resistance.
• unit weights and voids.
• absorption and surface moisture.

How do you calculate particle size distribution?

Particle size distribution and size averages are determined by particle counting in a Coulter counter (e.g., Multisizer 3). It provides number, volume, mass, and surface area size distributions in one measurement, with an overall sizing range of 0.4 μm to 1,200 μm.

What is the maximum size of particle in fine aggregate?

A maximum size up to 40 mm is used for coarse aggregate in most structural applications, while for mass concreting purposes such as dams, sizes up to 150 mm may be used. Fine aggregates, on the other hand, have particles up to a minimum size of 0.075 mm.

How is the size of an aggregate distribution measured?

Aggregate-size distribution often is measured to gain information on the size of the aggregates as they exist in the mass of soil.

How are aggregates used to describe particle distribution?

Once the proportions of the individual fractions are determined and plotted in graphical form as a gradation curve, the information can be used for more than just a report of grain sizes. The values can qualitatively group the aggregate with classification terms like gap-graded, open-graded, or uniformly-graded to describe particle distribution.

Which is true of the gradation of aggregates?

Definition. The particle size distribution of an aggregate as determined by sieve analysis is termed as gradation of aggregates. If all the particles of an aggregate are of uniform size, the compacted mass will contain more voids whereas aggregate comprising particles of various sizes will give a mass with lesser voids.The particle size

Why are there limits on the size of aggregate?

Grading limits and maximum aggregate size are specified because these properties affect the amount of aggregate used as well as cement and water requirements, workability, pumpability, and durability of concrete. In general, if the water-cement ratio is chosen correctly, a wide range in grading can be used without a major effect on strength.