EN 1097-9-2014 pdf download.Tests for mechanical and physical properties of aggregates – Part 9: Determination of the resistance to wear by abrasion from studded tyres – Nordic test.
4 Principle
A sample of a single-sized aggregate. 11,2 mm to 16,0 mm, is rotated together with steel balls and water in a
steel drum, Three ribs, which are mounted on the intenor of the drum, improve the mixing of the aggregate
particles and the steel balls. The contents roll within the drum with an abrading action, After the specified
number of revolutions, the contents are removed from the drum and the aggregate portion is steved on the
2 mm sieve to measure the wear as a percentage loss.
5 Apparatus
Unless otherwise stated, all apparatus shall conform to the general requirements of EN 932-5.
5.1 Standard apparatus
5.1.1 Balance, capable of weighing both the test specimen and the charge to an accuracy of 0.1 % of tfle mass of the test specimen.
5.1.2 Setofsieves. 2,0 mm; 11.2 mm; 14,0mm; 16,0 mm conforming to EN 933-2.
5.1.3 Guard sieve, for protecting the 2 mm sieve,
5.1.4 Ventilated oven, thermostatically controlled to maintain a temperature of (110 ± 5) C.
5.1.5 Means of washing the sieved sample.
5.1.6 quiprnent for reducing the laboratory samples, as specified in EN 932-2.
5.1.7 Graduated glass measuring cylinder (or cylinders), conforming to EN ISO 4788, or other means of
measuring (2,00 ± 0,01)1 of water,
5.2 Special apparatus
5.2.1 Testing machine, a typical testing machine is detailed in Figure 1 with essential characteristics as specified in 5.2.2 to 5.2.7
5.2.2 A watertight hollow drum, dosed at one end, having an inside diameter of (206,5 ± 2,0) mm and an internal length measured from the inside of the base to the inside of the lid of (335 ± 1) mm. The drum shall be made of a seamless steel tube conforming to grade TS 5 of ISO 9329-4, with a minimum wall thickness of 6,0 mm.
NOTE It is also acceptab4e to compose a suflent amount of the test sample 11.2/16 mm and then reduce this amount to the required mass of the test specimens.
7 Procedure
Place the charge of (7000± 10) g into the drum. Add then the test specimen and finally (2,00 ± 0,01)1 of water.
Fit the lid to the drum. Rotate the drum at a speed of (90 ± 3) r/min for (5400 ± 10) revolutions.
After the test, collect the aggregate and the steel balls in a pan, taking care to avoid the loss of any aggregate.
Using a washing bottle, carefully wash the inside of the drum and the lid, and retain the washings.
Empty the material and all the washings onto the 2,0 mm sieve, potected by an appropriate guard
sieve (5.1.3). Wash the material in a stream of clean water.
Carefully separate the aggregate particles retained on the guard sieve from the steel balls, taking care not to lose any aggregate particles. The aggregate particles can be picked out by hand, o the balls can be removed from the sieve using a magnet.
Place the aggregate particles retained on the guard sieve and the 2,0 mm sieve onto a tray.
Dry the tray and its contents in the oven at (110 ± 5) 0C to constant mass. Determine the mass of aggregate particles greater than 2 mm by dry sieving according to EN 933-1. Record the mass, M2, to the nearest gram.
Repeat the above procedure on a second test specimen.
8 Calculation and expression of results
For each test specimen calculate the Nordic abrasion value, AN, to the nearest single decimal place as follows:
4= 100(M1—M2)1M1
where
M is the initial dry mass of the test specimen, in grams;
M2 is the dry mass of aggregate particles greater than 2 mm, obtained after abrasion, in grams.
9.1 Required data
The test report shall include the following information:
a) reference to this European Standard;
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) particle size fraction tested;
f) Nordic abrasion values to the nearest single decimal place (mean value and each accepted individual value);
g) deviations from the reference method — if any.
9.2 OptIonal data
The test report can include the following information:
a) date of test;
b) reference to the chosen sampling procedure;
C) reference to the chosen sample reduction procedure;
d) mass of test portion;
e) individual test results with significant digits;
1) other influencing parameters.
10 Precision
The repeatability (r) and reproducibility (I?) have been determined on the basis of inter-laboratory studies in
1994 in the Nordic countries (eleven laboratories, eight levels and two test specimens at each level).
Interpretation of the test results has been made in accordance with ISO 5725-1:1994.
For Nordic abrasion values (AN) from 5 to 16, the precision was as follows:EN 1097-9-2014 pdf download.
EN 1097-9-2014 pdf download
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