BS EN 12697-39:2020 pdf free download – Bituminous mixtures一Test methods Part 39: Binder content by ignition.
To ensure consistent results, the temperature of the test portion after determining should not be allowed to cool from 110°C for more than 3 mm before loading into the furnace.
7.2.3 Weigh to 0,1 g and record the mass of the sample, sample basket(s) and catch pan W, in grams, on the external balance.
7.2.4 Place the sample baskets and catch pan in the furnace ensuring that they are not in contact with either the furnace wall or any temperature probe or other protrusion inside the furnace. Run the appropriate ignition programme after the oven has been pre-heated according to the manufacturer’s instructions.
7.2.5 Allow the test to continue until the balance indicator displays show that the sample mass has stabilized and so that the range of 3 consecutive weighing, taken at 1 mm intervals, is within the constant mass limit in Table 1. Remove the sample baskets, placing them on the heat-resistant surface, immediately covering with the heat guard and allow to cool to approximately room temperature to permit safe handling.
NOTE 1 Failure of the furnace scale to stabilize might indicate that the sample baskets are in contact with the furnace wall.
NOTE 2 The cooling time for samples removed from the furnace is dependent primarily on sample size and dispersion in the baskets. The time taken to cool to approximately room temperature is unlikely to be less than
30 mm.
7.2.6 Record the loss of mass W10, in grams, from the internal balance. Then weigh and record the mass of the sample, sample baskets and catch pan Wt+a, in grams, to 0,1 g on the external balance.
Wt+a need not be measured if B is to be calculated using W10 directly, but B should be calculated using
W and Wa whenever used for reference purposes because the internal balance measures the mass loss
at elevated temperature.
7.3 Procedure for furnace without internal balance (Method B)
7.3.1 Weigh to 0,1 g and record the mass of the sample basket(s) and catch pan w, in grams, at room temperature. Place the sample basket(s) in the catch pan and evenly distribute the specimen in the basket(s). Weigh to 0,1 g and record the mass of the sample, sample basket(s) and catch pan in grams.
7.3.2 Heat the sample in the furnace at the test temperature ± 5 °C for the time determined during the calibration ± 5 mm.
7.3.3 Remove the sample from the furnace and allow it to cool to below 35 °C. Weigh to 0,1 g and record the mass of the sample, sample basket(s) and catch pan Wt+a in grams.
7.3.4 Return the sample back into the furnace. After the furnace reaches the set point temperature, heat the sample for a further 15 mm. Repeat 7.3.3 to determine the mass of the sample after the extended ignition period.
7.3.5 Repeat 7.3.4 until the change in the mass of the sample after 15 mm of further ignition is less than the constant mass limit in Table 1.
8.2.4 Calculate the corrected binder content of the sample by mass of the bituminous mixture sample B, in percent, in accordance with 8.1.4.
9 Test report
The test report shall include the following information:
a) identification number, type of mixture and composition;
b) date and time of testing and name of operator;
c) reference to this document;
d) calibration value and the method used for determining the calibration value;
e) maximum temperature during testing;
f) binder content (rounded to nearest 0,1 % by mass);
g) aggregate grading and aggregate density, when required;
h) any observation which may have an influence on the evaluation.