What do you mean by aggregate function?

What do you mean by aggregate function?

An aggregate function is a mathematical computation involving a set of values that results in a single value expressing the significance of the data it is computed from. Aggregate functions are often used in databases, spreadsheets and many other data manipulation software packages now common in the workplace.

What is the use of aggregate function?

An aggregate function performs a calculation on a set of values, and returns a single value. Except for COUNT(*) , aggregate functions ignore null values. Aggregate functions are often used with the GROUP BY clause of the SELECT statement.

What is the function of aggregate in concrete?

Aggregates make up 60-80% of the volume of concrete and 70-85% of the mass of concrete. Aggregate is also very important for strength, thermal and elastic properties of concrete, dimensional stability and volume stability. Cement is more likely to be affected by shrinkage.

What are the properties of aggregate suitable for road construction?

Not only that aggregates should be strong and durable, they should also possess proper shape and size to make the pavement act monolithically. Aggregates are tested for strength, toughness, hardness, shape, and water absorption.

Why is aggregate important?

Aggregate occupies most of the volume of the concrete. It is the stuff that the cement paste coats and binds together. The composition, shape, and size of the aggregate all have significant impact on the workability, durability, strength, weight, and shrinkage of the concrete.

Can I make concrete without aggregate?

Concrete without aggregate is know as mortar. Mortar happens to be a mixture of fine aggregate such as sand and a binding material like cement mixed together with water. The cement sand ratio depends on the purpose mortar is used for. ... For making a cube M25, what is the ratio of cement, sand, and aggregate?

What is specific gravity of fine aggregate?

Specific gravity of fine aggregate (sand) is the ratio of the weight of given volume of aggregates to the weight of equal volume of water. The specific gravity of sands is considered to be around 2.

How do you calculate specific gravity of aggregate?

The coarse aggregate specific gravity test (Figure 1) is used to calculate the specific gravity of a coarse aggregate sample by determining the ratio of the weight of a given volume of aggregate to the weight of an equal volume of water. It is similar in nature to the fine aggregate specific gravity test.

What is the purpose of specific gravity test?

Knowing the specific gravity will allow determination of a fluid's characteristics compared to a standard, usually water, at a specified temperature. This will allow the user to determine if the test fluid will be heavier or lighter than the standard fluid.

What is the difference between density and specific gravity?

Density is defined as mass per unit volume. It has the SI unit kg m-3 or kg/m3 and is an absolute quantity. Specific gravity is the ratio of a material's density with that of water at 4 °C (where it is most dense and is taken to have the value 999.

Is density greater than specific gravity?

Converting Between Density and Specific Gravity Density is very slightly less than specific gravity.

What is the difference between density and relative?

Density is by definition the ratio of the mass and volume of a body. ... Relative density is the ratio between the density of a measuring substance and the density of some other reference substance at a given temperature (typically water).

What is difference between mass and volume?

Volume – How much space an object or substance takes up. Mass – Measurement of the amount of matter in an object or substance.