Los Angeles Abrasion Test

Los Angeles Abrasion Test of Aggregates : Lab Procedure, Importance, Precautions & Standard Values


The Los Angeles Abrasion Test is carried out on aggregates in order to determine the hardness and abrasion characteristics i.e. ability to resist degradation due to imposed wheel load.

The principle of this test is to determine the percentage of wear due to deliberate rubbing action between aggregates.

Steel balls are used as an abrasive charge for creating the rubbing action in the test.

The percentage wear of the aggregates due to rubbing with steel balls is taken as abrasion value.



  1. Importance of Los Angeles Abrasion Test  

a. It helps to determine the strength, toughness, relative quality, abrasion characteristics, and physical behavior of aggregates.

b. It gives the idea to improve the properties of aggregates (asphalt or concrete) to bear the load and to be workable, reliable, and durable for stable and stiff structures.

c. This test indicates that the materials having more abrasion is quite less hard and can be easily damaged.



  2. Apparatus Required   

a. Weighing Balance

b. Sieves as per gradation of aggregate 80mm, 63mm, 50mm, 40mm, 25mm, 20mm, 12.5mm, 10mm, 6.3mm, 4.75mm, and 1.7mm.

c. Abrasion testing machine with an inside diameter of 70 cm and inside length of 50 cm.

d. Steel balls (abrasive charge) of diameter 48mm and weighing between 390g to 445g.

Selection of Abrasive Charge for Los Angeles Abrasion Test

GradingNo. of Steel ballsWeight of charge in gm.
A125000 ± 25
B114584 ±25
C83330 ± 20
D62500 ± 15
E125000 ± 25
F125000 ± 25
G125000 ± 25


Grading of Test Samples – *Tolerance of ± 12 %permitted




  3. Procedures in Los Angeles Abrasion Test  


Los Angeles Abrasion Test


1. The test sample must contain clean well-graded aggregates that have been oven-dried at a temperature ranging from 105 degrees to 110 degrees Celsius.

2. Then, the aggregates along with the abrasive charges are placed in the Los Angeles Abrasion Testing Machine.

3. The machine is then rotated at a speed of 20 to 33 rev/min.

4. The machine shall be driven such that a substantially uniform peripheral speed is maintained.

5. After the completion of the test, the coarse aggregate is taken out and passed through sieves.

6. The aggregates coarser than 1.7 mm IS sieve are then separated.

7. The retained aggregates are then oven-dried at the temperature of 105 – 110 ºC and are finally weighed.

8. The Los Angeles Abrasion Value is then calculated using the following formula:

Abrasion value = [ (A-B) / A ] * 100


A= weight in gm of oven-dried sample

B= weight in gm of the fraction of aggregate retained on 1.7mm sieve after oven-dried



  4. Suitable Abrasion Value for Pavements

Sl. No.Type of PavementMax. permissible abrasion value in %
1Water bound macadam sub base course60
2WBM base course with the bituminous surfacing50
3Bituminous bound macadam50
4WBM surfacing course40
5Bituminous penetration macadam40
6Bituminous surface dressing, cement concrete surface course35
7Bituminous concrete surface course30



  5. Precautions in Los Angeles Abrasion Test  

a. While performing the LA abrasion test, it should be concerned that the abrasion machine is being rotated about (20-33) rpm.

b. Test should be performed at room temperature to avoid humidity causing errors.


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