Testing of industrial products - Aggregates for construction

The method for the determination of the Particle Density of Fillers

The principle of the method

The volumes of pyknometers to be used in the test are established first by weighing them both empty and full of water. Next, the density of the liquid to be used is established by weighing a pyknometer both empty and full of the liquid. Once these calibrations have been completed, the particle density of a test specimen of filler is determined from three masses: the mass of an empty pyknometer, the mass of the pyknometer containing a test specimen of the filler, and the mass of the pyknometer containing the test specimen and topped up with a liquid.

Pyknometers of nominal capacity 50 mL are used, and the test specimen mass should be about 10 g. A vacuum dessicator is used to remove air prior to weighing a pyknometer containing the test specimen and topped up with liquid. Before a pyknometer is to be weighed containing liquid it is placed in a water bath at 25.0 ± 0.1 °C for at least 60 minutes. All weighings are carried out to an accuracy of 0.01 g.

The proposed CEN method

The proposed CEN method is one that has been used for many years to determine the particle densities of fillers and other powders (such as cement). The CEN method allows the use of any suitable liquid in which the filler does not dissolve and with which the filler does not react - it states that toluene is preferable but that water, ethanol and xylene may also be used. It requires three determinations of particle density to obtain the test result for a filler, but a single determination of the volume of a pyknometer or of the density of a liquid.

Participants in the cross-testing experiment were sent copies of the method that was prepared in July, 1996, for submission to CEN members for CEN enquiry.