BS 1744-4:2021 pdf download – Tests for chemical properties of aggregates Part 4: Determination of water susceptibility of fillers for bituminous mixtures
5.2.12 Well-ventilated oven, capable of maintaining a temperature of (110 ± 5) °C.
5.2.13 Graduated measuring cylinder, 100 ml capacity.
5.2.14 Two thermometers, 0 °C to 100 °C with 1 °C sub-divisions.
5.2.15 Stop-watch, or timer, readable to 1 s.
5.2.16 Büchner funnel, 90 mm diameter.
5.2.17 Vacuum flask, with suitable Büchner funnel adapter.
5.2.18 Medium grade filter paper, ashless, for quantitative analysis, of a diameter appropriate to the size of the funnel (5.2.16).
5.3 Sampling
The laboratory sub-sample shall be taken in accordance with EN 932-1 and reduced in accordance with EN 932-2, to produce a mass of about 50 g.
5.4 Preparation of test portions Dry the reduced mass of filler in an oven at a temperature of (110 ± 5) °C to constant mass and cool to room temperature in a desiccator for at least 90 min. If agglomerates are present in the material, reduce these agglomerates to powder by means of a spatula. Mix the pulverised agglomerates with the rest of the sub-sample and sieve the sub-sample through the 0,125 mm sieve. Remix the material passing the sieve and take (10 ± 0,1) g as the test portion (m0). 5.5 Procedure Place (50,0 ± 0,5) g of low viscosity bitumen solution (5.1.3) into the conical flask or the tinplate can and add the test portion of filler to the conical flask or tinplate can.
Measure (100 ± 5) ml of demineralized water into the measuring cylinder. Place the conical flask or the tinplate with the lead cap and the measuring cylinder in the water bath until a temperature of (60 ± 1) °C has been reached by the contents of both vessels (checking by means of thermometers) and maintain this temperature during the test. Stir the contents of the conical flask or the tinplate can with its lead cap mechanically for (300 ± 5) s and then allow the mixture to stand for (300 ± 5) s. Pour the water from the measuring cylinder into the conical flask or the tinplate can with the lead cap and stir again for (300 ± 5) s.
In the case of use of tinplate can, the supernatant water is to be transferred into a beaker, to see if uncoated filler has separated. In the case of a use of a glass conical flask, examine the mixture to see if uncoated filler has separated. If not, the filler shall be considered as non-susceptible to water. If the filler separates, or in the case of turbidity of the water, determine the water susceptibility as follows. Allow the conical flask or the tinplate can and its contents to cool so that the mixture becomes kneadable. Pour the water and the filler separated from the mixture by kneading in the flask with a spatula and washing with water.
Pour the water and the separated filler into the beaker and repeat the process until the washing with water becomes clear. Weigh a dried filter paper and records its mass (m 1 ). Filter the contents of the beaker through the weighed filter paper in a Büchner funnel to the vacuum flask. Remove the last traces of bitumen by washing with kerosene (5.1.2). Dry the filter and recovered filler in an oven at (110 ± 5) °C to constant mass.
Weigh the filter paper with the filler to the nearest 1 mg (m 2 ).
5.6 Calculation and expression of results
Calculate the water susceptibility (W s ), as a percentage by mass of the filler, in accordance with the following equation:
m 0 is the mass of the test portion in grams;
m 1 is the mass of the filter paper in grams;
m 2 is the mass of the filter paper and filler in grams.
W s should be rounded to the nearest 1 % by mass.
5.7 Test report
The test result shall be accompanied by an affirmation that the water susceptibility was determined in accordance with this document.
The test report shall include the following information:
a) reference to this document;
b) identification of the test sample, including identification of the source and date of sampling;
c) sample reception date if different from sampling date;
d) identification of the laboratory;
e) the test results for water susceptibility;
f) deviations from the reference method – if any.BS 1744-4 pdf download.