Test for determination of aggregate abrasion value

Los Angeles Abrasion Test,

Goal:

To determine the Abrasion Value

To select suitable aggregates for specific use.

Apparatus:

1. Los Angeles Machine Consist of hollow steel cylinder close at both end 

2. Abrasive charge(Twelve  Cast iron or steel balls diameter of to 48mm and weight between 390 to 445g )

3. sieve1.70, 2.36,4.75,6.3,10,12.5,20,25,40,50,63,80 mm.

4. Balance Capacity 5kg to 10kg.

5. Drying oven (105 to 1100C)

6. Tray

Theory:

The Aggregates that are used in highway pavement must be hard and tough to resist crushing, degradation and disintegration.They  Aggregates Should be able to effectively transmit load from the pavement surface to subgrade. The resistance to abrasion of aggregates is determined in Los Angeles test Machine.

Procedure;

1. Prepared sample is settled   in the Abrasion-Testing Machine.

2. A specified number of steel balls are placed in the machine.

3. The drum is rotated for 500 revolutions at a speed of 30 - 33 revolutions per minute 

4. Stopped Abrasion-Testing Machine after the desired number of revolutions is complete.

5. The material is then separated into material passing the 1.70 mm   and material retained on the 1.70 mm sieve.

6. Calculate %age loss due to Abrasion.

OBSERVATIONS:

Original weight of aggregate sample = W1 g

Weight of aggregate sample retained =  W2 g

Weight passing 1.7mm IS sieve = W1 – W2 g

Abrasion Value = (W1 – W2 ) / W1 X 100

RESULT:

Los Angeles Abrasion Value =

• Crushing test.
• Abrasion test.
• Impact test.
• Soundness test.
• Shape test.
• Specific gravity and water absorption test.
• Bitumen adhesion test.