Test to Determine the Abrasion
Value
Abrasion
Test
Measurement of toughness and
resistance like degradation, crushing, and disintegration is the right
definition of the Abrasion test.
This test is suggested by AASHTO T
96 or ASTM C 131 Resistance to degradation of small coarse
aggregates by Abrasion and impact on the Los Angeles Machine.
Aggregates are used for the surface course of road
pavements and are subject to wear and tear due to traffic movement. (ASTM
c131 Los Angeles abrasion test)
Therefore, aggregates
used in road construction must be hard enough to resist Abrasion. The
resistance offered by the aggregate
to Abrasion is determined in the laboratory by the Los Angeles testing machine.
The Los Angeles abrasion test’s working principle is to produce abrasive
action using standard steel balls, which, when mixed with aggregates and spun
in a drum for a specified time for a specific number of revolutions, also
impact the aggregates.
The percentage of wear of sample aggregates due to friction with steel balls
is determined and is known as the Los Angeles Abrasion Value.
Test to Determine the Abrasion Value
The abrasion test on aggregates in
Los Angeles is carried out with the following objectives:
- To discover the value of Abrasion in Los Angeles
aggregate.
- Find the suitability of aggregates for use in road
construction projects.
Apparatus
Used For Abrasion Test
The device is standardized according
to IS: 2386 (Part IV) – 1963 consists of:
- Los Angeles abrasion machine
- Abrasive load spheres: Spheres of cast iron or steel,
approximately 48 mm in diameter and each weighing between 390 and
445 g; six to twelve balls are needed
- Sieve: 1.70 mm, 2.36 mm, 4.75 mm, 6.3 mm, 10 mm, 12.5
mm, 20 mm, 25 mm, 40 mm, 50 mm, 63 mm, 80 mm IS sieves.
- The 5 kg or 10 kg capacity balance is used.
- Miscellaneous like a tray
- Abrasive load spheres: Spheres of cast iron or steel,
approximately 48 mm in diameter and each weighing between 390 and
445 g; six to twelve balls are needed
Procedure
For Abrasion Test
- Select the grading to be utilized in the test such that
it conforms to the grading to be utilized in construction,
to the maximum extent possible.
- Require 5 kg of sample for gradings A, B, C, and; D,
and 10 kg for gradings E, F & G.
- Pick the abrasive charge according to Table 1,
depending on the grading of aggregates.
- Place the aggregates and abrasive charge to the
cylinder and fix the cover.
- Rotate the machine at a speed of 30 to 33 revolutions
per minute. The number of revolutions is 500 to get gradings A, B, C, and
D, and 1000 for gradings E, F, and G. The machine ought to be balanced and
driven such that there’s uniform peripheral speed.
- The machine is stopped after the desired number of
revolutions and material is discharged to a tray.
- The entire stone dust is sieved on 1.70 mm IS sieve.
- The material coarser than 1.7mm size is weighed correct
to one gram.
|
Grading
|
No
of Steel balls
|
Weight
of charge in gm.
|
|
A
|
12
|
5000
± 25
|
|
B
|
11
|
4584
±25
|
|
C
|
8
|
3330
± 20
|
|
D
|
6
|
2500
± 15
|
|
E
|
12
|
5000
± 25
|
|
F
|
12
|
5000
± 25
|
|
G
|
12
|
5000
± 25
|
Table-1 Selection of Abrasive
|
Source
|
|
Tested as per
|
|
|
|
|
|
Weight of sample taken (gms)
|
|
Confirmation as per
|
|
|
|
|
Sieve
size (square hole)
Passing (mm)
|
Weight
of test sample in gm
Retained on (mm)
|
A
|
B
|
C
|
D
|
E
|
F
|
G
|
|
|
|
80.0 mm
|
63.0 mm
|
|
|
|
|
|
|
|
|
|
|
63.0 mm
|
50.0 mm
|
|
|
|
|
|
|
|
|
|
|
50.0 mm
|
40.0 mm
|
|
|
|
|
|
|
|
|
|
|
40.0 mm
|
25.0 mm
|
|
|
|
|
|
|
|
|
|
|
25.0 mm
|
20.0 mm
|
|
|
|
|
|
|
|
|
|
|
20.0 mm
|
12.5 mm
|
|
|
|
|
|
|
|
|
|
|
12.3 mm
|
10.0 mm
|
|
|
|
|
|
|
|
|
|
|
10.0 mm
|
6.3 mm
|
|
|
|
|
|
|
|
|
|
|
6.3 mm
|
4.75 mm
|
|
|
|
|
|
|
|
|
|
|
4.75 mm
|
2.36 mm
|
|
|
|
|
|
|
|
|
|
|
Pan
|
|
|
|
|
|
|
|
|
|
|
|
Remarks ( If Any) –
|
|
|
|
|
|
|
|
Contractor
|
PMC
|
Client
|
|
Table-2
Format of Abrasion Test Report
Also, read: What Is Slump Cone Test |
Principle of Slump Test | Types of Concrete Slump
Principle
of Abrasion Test
Steel ball bearings in the hardness
test To produce the abrasive action using standard steel balls that, when mixed
with the aggregate and rotated in a drum for a specific number of revolutions,
impact the aggregate.
The wear per age due to friction
with steel balls is determined and is known as the abrasion value. Prepare the
sample by the portion of an aggregate sample retained in the 1.70 mm (# 12)
sieve and place in a large rotating drum that contains a shelf plate attached
to the outer wall.
Also, read: Mortar Vs Cement | Type of
Cement | Type of Mortar
Standard
Test Methods of Abrasion Test
The standard test method for
Abrasion test are as follows.
- AASHTO T 96 and ASTM C 131: Resistance to degradation
of coarse aggregate of small size by Abrasion and impact on the Los
Angeles machine
- ASTM C 535: Resistance to degradation of large coarse
aggregates by Abrasion and impact on the Los Angeles machine.
Uses
Of The Abrasion Test
For an aggregate to perform
satisfactorily on the pavement, it must be difficult enough to resist the
abrasive effect of traffic for a long period of time.
Soft aggregates will be quickly
crushed into powder, while hard aggregates are quite resistant to crushing.
The test will also determine the
quality of the aggregate.
The L.A. abrasion test is widely
used as an indicator of the quality or relative competence of mineral
aggregates.
Also, read: Mivan Shuttering | Merit &
Demerit Mivan Technology | Mivan Formwork Assembly Process
How
Does the La-Abrasion Test Works?
- A sample is prepared by separating the required masses
into individual size fractions.
- The sample of specific size aggregates and the abrasive
load are placed on the L.A. Abrasion Machine and spun at 30-33rpm.
- The sample is removed and washed over a No. 12 sieve
(1.70 mm) and placed in an oven to dry.
- The percentage loss or the difference between the
original mass and the final mass.
- A. abrasion loss value of 40 indicates that 40% of the
original mass of the sample passed through the sieve.
Important
of Abrasion Test
- The abrasion test determines the relative quality,
strength, and durability
of mineral aggregates subject to impact and Abrasion.
- The values derived from L.A. Abrasion tests provide
information on the performance of aggregate in use. This test provides
insight into how asphalt and concrete aggregates resist wear and tear over
time.
- It is also a good indicator of change in properties in
an aggregate source as part of a quality assurance or control program.
IS
Recommended Los Angeles abrasion test Values for Pavements:
A Los Angeles test is performed to
find the hardness of aggregates. On the basis of this value, the suitability of
aggregates for different road constructions can be judged as per IRC
specifications as given.
|
SI. No.
|
Type of Pavement
|
Max. permissible abrasion value in
%
|
|
1
|
Water bound macadam sub base
course
|
60
|
|
2
|
WBM base course with bituminous
surfacing
|
50
|
|
3
|
Bituminous bound macadam
|
50
|
|
4
|
WBM surfacing course
|
40
|
|
5
|
Bituminous penetration macadam
|
40
|
|
6
|
Bituminous surface dressing,
cement concrete surface course
|
35
|
|
7
|
Bituminous concrete surface course
|
30
|
Conclusion
of Abrasion Test
It is important to remember that,
regardless of the method chosen, abrasion testing is a necessary procedure as
part of a quality control process to assess how materials will react to wear
over time.
FAQ
Abrasion
Test
Abrasion testing is used
to test the abrasive resistance of solid materials. The intent of abrasion
testing is to produce data that will reproducibly rank materials in their
resistance to scratching abrasion under a specified set of conditions.
Why
Abrasion Test Is Done?
Abrasion test is carried
out to test the hardness property of aggregates. The principle
of Los Angeles abrasion test is to find the percentage wear due to
relative rubbing action between the aggregate and steel balls used as abrasive
charge.
What
Is a Abrasion Test?
Abrasion testing is used
to test the abrasive resistance of solid materials. The intent
of abrasion testing is to produce data that will reproducibly rank
materials in their resistance to scratching abrasion under a specified set
of conditions.
How
Do You Perform an Abrasion Test?
- The sample of specifically sized aggregates and the
abrasive charge is placed in the L.A. Abrasion Machine and rotated at
30-33rpm.
- The sample is removed and washed over a No. 12 (1.70mm)
sieve and placed in an oven to dry.
- The percent loss or the difference between the original
mass and the final mass is calculated.
- An L.A. Abrasion loss value of 40 indicates that 40% of
the original sample mass passed through the sieve.
What
Is Los Angeles Abrasion Test?
Abrasion test is carried out to test the hardness
property of aggregates. The principle of Los Angeles abrasion test is
to find the percentage wear due to relative rubbing action between the
aggregate and steel balls used as abrasive charge.
What
Are the Three Types of Abrasion?
Three forms of abrasion occur
and are tested for most frequently, namely flat (plane or
surface) abrasion, edge abrasion (i.e. at collars and folds) and
flex (flexing and bending) abrasion.
What
Is the Purpose of Abrasion Test?
Abrasion testing is used to test the abrasive
resistance of solid materials. Materials such as metals, composites,
ceramics, and thick (weld overlays and thermal spray) coatings can be tested
with these methods.
Why
Is the Abrasion Test Important in Los Angeles?
The Los Angeles (L.A.) abrasion
test is a common test method used to indicate
aggregate toughness and abrasion characteristics.
Aggregate abrasion characteristics are important
because the constituent aggregate in HMA must resist crushing, degradation and
disintegration in order to produce a high quality HMA.
What
Is Abrasion Value Test?
Abrasion Test is the measure of
aggregate toughness and abrasion resistance such as crushing,
degradation and disintegration. The percentage wear of the sample aggregates
due to rubbing with steel balls is determined and is known as Los
Angeles Abrasion Value.
What
Do You Mean by Abrasion Value?
The Los Angeles
(L.A.) abrasion test (Figure 1) is a common test method used
to indicate aggregate toughness and abrasion characteristics. Therefore,
an L.A. abrasion loss value of 40 indicates that 40% of the original
sample passed through the No. 12 (1.70 mm) sieve.
How
Do You Calculate the Abrasion Value?
- The material coarser than 1.70mm IS Sieve should be
washed, dried in an oven at a temperature of 100 to 110oC to a
constant weight, and weighed (Weight ‘B’)
- 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, Aggregate
abrasion value = (A-B)/B x 100%
Which
Test Is Also Known as Abrasion Test?
The Los Angeles (L.A.) Abrasion
Test is widely used as an indicator of the relative quality of aggregates.
It measures the degradation of standard gradings of aggregates when subjected
to abrasion and impact in a rotating steel drum with
an abrasive charge of steel balls.
Why
Is Abrasion Important?
Abrasion is a principal factor that
causes rupture of the materials like rubbers, ceramics, coatings, metals, etc.
Abrasion test provides the result that helps the user to compare the material
or its coating and helps to judge the life of the material.
What
Is Abrasion Value of Aggregate?
The abrasion value of an aggregate
is the value that determines aggregate toughness and abrasion resistance. It
includes properties of aggregate such as crushing value, degradation, and
disintegration.
Procedure
For Abrasion Test
- Select the grading to be utilized in the test such that
it conforms to the grading to be utilized in construction, to the maximum extent
possible.
- Require 5 kg of sample for gradings A, B, C, and; D,
and 10 kg for gradings E, F & G.
- Pick the abrasive charge according to Table 1,
depending on the grading of aggregates.
- Place the aggregates and abrasive charge to the
cylinder and fix the cover.
- Rotate the machine at a speed of 30 to 33 revolutions
per minute. The number of revolutions is 500 to get gradings A, B, C, and
D, and 1000 for gradings E, F, and G. The machine ought to be balanced and
driven such that there’s uniform peripheral speed.
- The machine is stopped after the desired number of
revolutions and material is discharged to a tray.
- The entire stone dust is sieved on 1.70 mm IS sieve.
Principle
of Abrasion Test
Steel ball bearings in the hardness
test To produce the abrasive action using standard steel balls that, when mixed
with the aggregate and rotated in a drum for a specific number of revolutions,
impact the aggregate.
The wear per age due to friction
with steel balls is determined and is known as the abrasion value. Prepare the
sample by the portion of an aggregate sample retained in the 1.70 mm (# 12)
sieve and place in a large rotating drum that contains a shelf plate attached
to the outer wall.
Standard
Test Methods of Abrasion Test
The standard test method for
Abrasion test are as follows.
- AASHTO T 96 and ASTM C 131: Resistance to degradation
of coarse aggregate of small size by Abrasion and impact on the Los
Angeles machine
- ASTM C 535: Resistance to degradation of large coarse
aggregates by Abrasion and impact on the Los Angeles machine.
Uses
Of The Abrasion Test
For an aggregate to perform
satisfactorily on the pavement, it must be difficult enough to resist the
abrasive effect of traffic for a long period of time.
Soft aggregates will be quickly
crushed into powder, while hard aggregates are quite resistant to crushing.
The test will also determine the
quality of the aggregate.
The L.A. abrasion test is widely
used as an indicator of the quality or relative competence of mineral
aggregates.
How
Does the La-Abrasion Test Works?
- A sample is prepared by separating the required masses
into individual size fractions.
- The sample of specific size aggregates and the abrasive
load are placed on the L.A. Abrasion Machine and spun at 30-33rpm.
- The sample is removed and washed over a No. 12 sieve
(1.70 mm) and placed in an oven to dry.
- The percentage loss or the difference between the
original mass and the final mass.
- A. abrasion loss value of 40 indicates that 40% of the
original mass of the sample passed through the sieve.
Important
of Abrasion Test
Abrasion test is carried
out to test the hardness property of aggregates. The principle
of Los Angeles abrasion test is to find the percentage wear due to
relative rubbing action between the aggregate and steel balls used as abrasive
charge.
What
Is a Abrasion Test?
Abrasion testing is used
to test the abrasive resistance of solid materials. The intent
of abrasion testing is to produce data that will reproducibly rank
materials in their resistance to scratching abrasion under a specified set
of conditions.
How
Do You Perform an Abrasion Test?
- The sample of specifically sized aggregates and the
abrasive charge is placed in the L.A. Abrasion Machine and rotated at
30-33rpm.
- The sample is removed and washed over a No. 12 (1.70mm)
sieve and placed in an oven to dry.
- The percent loss or the difference between the original
mass and the final mass is calculated.
- An L.A. Abrasion loss value of 40 indicates that 40% of
the original sample mass passed through the sieve.
What
Is Los Angeles Abrasion Test?
Abrasion test is carried out to test the hardness
property of aggregates. The principle of Los Angeles abrasion test is
to find the percentage wear due to relative rubbing action between the
aggregate and steel balls used as abrasive charge.
What
Are the Three Types of Abrasion?
Three forms of abrasion occur
and are tested for most frequently, namely flat (plane or
surface) abrasion, edge abrasion (i.e. at collars and folds) and
flex (flexing and bending) abrasion.
What
Is the Purpose of Abrasion Test?
Abrasion testing is used to test the abrasive
resistance of solid materials. Materials such as metals, composites,
ceramics, and thick (weld overlays and thermal spray) coatings can be tested
with these methods.
Why
Is the Abrasion Test Important in Los Angeles?
The Los Angeles (L.A.) abrasion
test is a common test method used to indicate
aggregate toughness and abrasion characteristics.
Aggregate abrasion characteristics are important
because the constituent aggregate in HMA must resist crushing, degradation and
disintegration in order to produce a high quality HMA.
What
Is the Use of Abrasion Test?
Abrasion testing is used
to test the abrasive resistance of solid materials. Materials
such as metals, composites, ceramics, and thick (weld overlays and thermal
spray) coatings can be tested with these methods.
What
Does the LA Abrasion Test Measure?
The Los Angeles (L.A.) Abrasion
Test is widely used as an indicator of the relative quality of
aggregates. It measures the degradation of standard gradings
of aggregates when subjected to abrasion and impact in a
rotating steel drum with an abrasive charge of steel balls.
How
Is LA Abrasion Value of Aggregate Determined?
Abrasion Test is the measure
of aggregate toughness and abrasion resistance such
as crushing, degradation and disintegration. The
percentage wear of the sample aggregates due to rubbing with
steel balls is determined and is known as Los Angeles Abrasion
Value.
How
Do You Find the Aggregate Abrasion Value?
Aggregate abrasion value = (A-B)/B x 100%.
What
Properties of Aggregates Are Determined by Los Angeles Test?
Abrasion test is carried
out to test the hardness property of aggregates. The principle
of Los Angeles abrasion test is to find the percentage wear
due to relative rubbing action between the aggregate and steel balls used
as abrasive charge.
