TEST METHOD
WA 220.2 – 2012
LOS ANGELES ABRASION VALUE OF CRUSHED LIMESTONE
1
6
SCOPE
This method describes the procedure for the
determination of the Los Angeles Abrasion Value of
crushed limestone.
2
SAFETY
This method does not attempt to address all of the
safety concerns, if any, associated with its use. It is the
responsibility of the user of this method to establish
appropriate occupational health and safety practices
that meet statutory regulations.
3
Australian Standards
4
(a) Prepare the required unwashed amount of each
fraction (see Table 1) by sieving representative material
on appropriate sieves by hand or in a mechanical
shaker.
(b) If the sample is being prepared for testing to
Table 1, the material, in excess of 5000 g, constitutes
the test sample for the remaining steps of this method.
Specification for test sieves.
(d) Oven-dry each fraction at 105°C to 110°C until
constant mass, as described in WA 110.1 is achieved.
Main Roads Western Australia
WA 105.1
Test portions shall be prepared as follows:
(c) Place each separate fraction in a suitable wire mesh
basket or other appropriate container and wash the
material thoroughly by submerging and agitating the
container and contents in water until the water remains
clear.
REFERENCED METHODS
AS1152:
PREPARATION OF TEST PORTIONS
Preparation of Disturbed Soil and
Granular Pavement Material Samples for
Testing
(e) Allow the material to cool by standing in laboratory
ambient conditions for a minimum of 4 hours.
(f) Obtain the required washed amounts of each
fraction and combine these to comply with the selected
test grading (see Table 1).
APPARATUS
(a) Balance of at least 16 kg capacity readable to 0.1 g
and with a Limit of Performance (F) of not more than
0.5 g.
7
PROCEDURE
The test procedure shall be as follows:
(c) Crusher (or other suitable equipment)—for reducing
the spalls and cores to the required sizes.
(a) Check and record the mass of the test portion (
to the nearest gram.
)
(d) Los Angeles machine as specified in Figure 1.
(b) Select and make up the appropriate steel ball
charge and check the mass of total charge (see
Table 1).
(e) Mechanical sieve shaker (optional) suitable for
300 mm sieves.
(c) Inspect the Los Angeles abrasion testing machine
for cleanliness and brush out if necessary.
(f) A thermostatically controlled oven with good air
ventilation capable of maintaining a temperature, within
the range of 105°C to 110°C.
(d) Place the test portion and steel ball charge in the
machine, place the cover plate into position and tighten
the cover plate clamp-nuts evenly and securely.
(g) Sample divider as described in WA 105.1, Clause
4(b).
(e) Set the revolution counter to 250 and allow the
machine to operate continuously for 250 revolutions.
(h) Sieves, complying with AS 1152, as required.
(f) On completion, remove the cover plate, turn the
drum until the aperture is at the bottom and then
remove the test portion and charge of steel balls from
the drum into the tray by hitting the drum with a rubber
mallet and then cleaning the interior thoroughly with a
soft brush. Take special care to avoid loss of material.
5
SELECTION OF TEST GRADING
The test portion shall consist of a combination of
aggregate fractions obtained by sieving, washing and
riffling representative material to comply with a grading
given in Table 1.
MAIN ROADS Western Australia
Document 71/04/220.2
Issue Date: 08 February 2012
D10#217173
Page 1 of 5
(b) Brushes suitable for cleaning sieves, containers
and machine.
TEST METHOD
(g) Remove the steel ball charge from the sample.
Assemble the 300 mm diameter sieves in order 75.0,
53.0, 37.5, 26.5, 19.0, 9.50, 6.75, 4.75 and 1.70 mm
and pan, and sieve the test portion by hand or in a
mechanical sieve shaker.
(h) Determine the mass of the material passing the 1.70
. Combine all material
mm sieve and record as
coarser than the 1.70 mm sieve and weigh and record
as ( ). If the difference between the sum of the
masses and the original mass ( ) of the test portion
exceeds 0.5 percent of the original mass of the test
portion disregard the test and repeat completely using a
fresh test portion.
(i) Wash all material coarser than 1.70 mm in a
300 mm diameter 1.70 mm sieve with water until the
water remains clear.
(j) Transfer the washed material to a suitable container
and oven-dry at 105°C to 110°C until constant mass is
achieved.
WA 220.2 – 2012
10 SPECIAL PRECAUTIONS
The following special precautions shall be taken:
(a) The strength or toughness of the limestone depends
partly on its moisture and temperature. To maintain a
low variability between Los Angeles abrasion value
results, special attention shall be paid to the
standardized washing, drying and cooling procedures.
(b) The Los Angeles abrasion testing machine shall be
periodically checked for wear and maintained to comply
with the original specifications.
(c) Samples, subsamples and fractions shall be divided
as described in WA 105.1.
(d) The 1.70 mm sieve shall be checked regularly, to
ensure that it complies with AS 1152. New sieves
should also be checked.
(k) Cool the material for a minimum period of 1 hour, to
23 ± 2°C and re-sieve as in Procedure 7(g).
NOTE: Temperature limits are specified to suit airconditioned
laboratories.
Cooling
to
ambient
temperatures outside this limit may affect the
repeatability of the test.
(l) Combine all material coarser than the 1.70 mm
sieve size and weigh to the nearest 1 g ( ).
8
CALCULATION
The Los Angeles abrasion value shall be calculated
from the following equation:
100
Where:
= total mass of the washed and dried material
before abrasion, in grams
= mass of material retained on the 1.70 mm sieve
after abrasion, washing, drying and re-sieving, in grams
9
REPORTING
The following shall be reported:
(a) The Los Angeles value to the nearest whole
number.
(b) The selected test grading.
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(c) Reference to this Test Method, i.e. WA 220.2.
MAIN ROADS Western Australia
Document 71/04/220.2
Issue Date: 08 February 2012
D10#217173
TEST METHOD
WA 220.2 – 2012
TABLE 1
TEST PORTION GRADING AND BALL CHARGE
Nominal Material Size
(mm)
Mass and Grading of Test Portion
(g)
Passing
Retained
BLST
ELST
75.0
63.0
1,250
63.0
53.0
1,250
53.0
37.5
2,500
37.5
26.5
26.5
19.0
19.0
13.2
2,500
13.2
9.5
2,500
FLST
GLST
HLST
JLST
2,500
2,500
2,500
2,500
5,000
5,000
5,000±100
5,000±100
5,000±100
5,000±100
5,000±100
5,000±100
Number of Revolutions
250
250
250
250
250
250
Number of Balls
4
4
4
4
4
4
Total Mass of Balls (g)
1,665±10
1,665±10
1,665±10
1,665±10
1,665±10
1,665±10
Page 3 of 5
Total Sample Mass (g)
MAIN ROADS Western Australia
Document 71/04/220.2
Issue Date: 08 February 2012
D10#217173
TEST METHOD
WA 220.2 – 2012
MAIN ROADS Western Australia
Document 71/04/220.2
Page 4 of 5
FIGURE 1: LOS ANGELES MACHINE
Issue Date: 08 February 2012
D10#217173
TEST METHOD
WA 220.2 – 2012
11 ISSUING AUTHORITY
Document Owner
Delegated Custodian
Manager Materials Engineering
Pavements Manager
12 REVISION STATUS RECORD
Page No.
All
Description / Reference
Format Revision and Re-issue of Test Method
Page 5 of 5
All
Revision
Section
MAIN ROADS Western Australia
Document 71/04/220.2
Issue Date: 08 February 2012
D10#217173