2.3 AGGREGATE ABRASION VALUE
AIM
To determine the abrasion value of coarse aggregates as per
IS: 2386 (Part IV) - 1963.
APPARATUS
i) Los Angles abrasion testing machine
ii) IS Sieve of size - 1.7mm
iii) Abrasive charge - 12 nos. cast iron or steel spheres
approximately 48mm dia. and each weighing between 390
and 445g ensuring that the total weight of charge is 5000 +
25g
iv) Oven
PREPARATION OF SAMPLE
The test sample should consist of clean aggregates which has
been dried in an oven at 105 to 110 °C to a substantially constant
weight and should conform to one of the gradings shown in the
table below:
PROCEDURE
The test sample and the abrasive charge should be placed in the
Los Angles abrasion testing machine and the machine rotated at
a speed of 20 to 33 revolutions/minute for 1000 revolutions. At
the completion of the test, the material should be discharged and
sieved through 1.70mm IS Sieve.
REPORTING OF RESULTS
i) The material coarser than 1.70mm IS Sieve should be
washed, dried in an oven at a temperature of 100 to 110 °C to
a constant weight and weighed (Weight 'B').
ii) The proportion of loss between weight 'A' and weight 'B' of
the test sample should be expressed as a percentage of the
original weight of the test sample. This value should be
reported as,
A - B
Aggregate abrasion value = ———– x 100%
A
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