Density of hardened Concrete

Uses of Cement

Principle

The standard describes a method to determine the density of hardened concrete.

The density is calculated from the mass (weight) and volume, which are obtained from a hardened concrete test specimen.

Test specimens

Test specimens with a minimum volume of 1 liter are required. If the nominal size of the maximum aggregate particle is over 25 mm, the minimum volume of the specimen must be over 50 D3, when D is the maximum aggregate particle size.

Example: Maximum particle size of 32 mm requires a minimum volume of 1.64 liters.)

Determining the mass

The standard specifies 3 conditions under which the mass of the specimen can be determined:

·     As a delivered sample

·     Water saturated sample

·     Sample dried in warming cupboard (to constant mass)

Determining the volume

The standard specifies 3 methods to determine the volume of a specimen:

·     By displacement of water (reference method)

·     By calculation from the actual measured masses

·     By calculation from checked specified masses (for cubes)

Determining the volume by displacement of water is the most accurate method and the only one suitable for specimens of irregular design.

Test result

The density is calculated from the specimen mass obtained and its volume:

D=m/V       D=density in kg/m³

              m=mass of specimen at time of test in kg

              V=volume determined by the relevant method in m³

The result should be given to the nearest 10 kg/m³.