The Los Angeles Abrasion Test aims to determine the abrasion value of aggregates for suitability in road construction, assessing their hardness and toughness. The test involves weighing specific aggregate samples, rotating them in a machine with an abrasive charge, and measuring the percentage of wear after a set number of revolutions. Recommended maximum permissible abrasion values for different types of pavements are provided, with specifications for various aggregate types.

1. Name of the Experiment: Los Angeles Abrasion Test
Prepared By
Nurmohammad
Department of Civil Engineering
Dhaka International University
Course Code: CE 354
Course Title: Transportation Engineering Sessional I

2. IS 2386 | ASTM C131 | ASTM C535
Name of the Experiment: Los Angeles Abrasion Test

3. Test Objective
Significance
1.To determine the Los Angeles abrasion value.
2.To find the suitability of aggregates for use in road construction.
1. To select the most suitable aggregate for different kinds of
works based on the abrasion value.
2. The test is significant to determine the hardness (and
toughness) of the material.

4. 1. Los angles abrasion testing machine
Apparatus

5. 2. Cast iron or steel balls
Apparatus

6. 3. Weighing balance.
Apparatus

7. 4. A set of standard sieves.
Apparatus

8. 5. Drying Oven
Apparatus

9. 5. Tray
Apparatus

10. Preparation Of Test Specimen
1. Select the grading to be used in the test such that it conforms to the grading to
be used in construction.
2. Take 5 kg of sample for grades A, B, C & D and 10 kg for grades E, F & G.
3. The test sample consists of clean aggregates dried in oven at 105° - 110°C.

11. Procedure
1. Place the aggregates and abrasive charge on the cylinder and fix the cover.

12. 2. Rotate the machine at a speed of 30 to 33 revolutions per minute. The number
of revolutions is 500 for grades A, B, C & D and 1000 for grades E, F & G. The
machine should be balanced and driven such that there is uniform peripheral
speed.
3. The machine is stopped after the desired number of revolutions and material is
discharged to a tray.
Procedure

13. 4. The entire stone dust is sieved on 1.70 mm IS sieve.
5. The material coarser than 1.7mm size is weighed correct to one gram.
Procedure

14. Grading
No of
Steel balls
Weight of charge
in gm.
Number of
revolutions
A 12 5000 ± 25
500
B 11 4584 ±25
C 8 3330 ± 20
D 6 2500 ± 15
E 12 5000 ± 25
1000
F 12 5000 ± 25
G 12 5000 ± 25
Selection of Abrasive Charge

15. The difference between original and final weights of the sample represents the actual
wear. This value is expressed as a percentage of the original weight of the sample and
is reported as the percentage of wear.
Let the original weight of the aggregates, 𝑊1= 5000 gm.
Weight of aggregate retained on IS 1.7 mm sieve after the test, 𝑊2= 2250 gm.
Loss of weight due to wear, (𝑊1 - 𝑊2) = 2750 gm.
Los Angeles abrasion value in % =
𝑊1−𝑊2
𝑊1
X 100
=
2750
5000
X 100
= 55%
Calculation

16. Recommended Los Angeles Test Values for
Pavements
Sl.
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

17. Thank you
Do you have any questions…….