All You Need to Know About Los Angeles Abrasion Test

 


The Los Angeles test is to measure the roughness and toughness of aggregates and understand its characteristics. Because of the aggregate abrasion characteristics, you will come to know the quality and sturdiness. This test is done to know the resistance power of aggregates while crushing and degrading. It measures the degradation of the aggregates when subjected to abrasion. 

The Los Angeles testing apparatus includes:

  • A hollow cylindrical drum on a stand with open mouth in which we have to put the aggregates.
  • Steel spherical balls
  • A steel tray
  • An automated computer called control panel, to note the weight and count number of rotations
  • Road or highway aggregates
  • Sieve (1.70 mm) 

The procedure of Los Angeles test

  • Firstly, the collected aggregates are added in the cylindrical drum. Before placing the aggregates, make sure to measure the weight to calculate the loss in the end.
  • Then some steel balls are added in the drum and covered with the lid.
  • Then the machine is started and rotated till 500 revolutions. The machine will automatically stop. There is nearly 30-35 revolution per minute.
  • The small particles are separated from the larger ones by passing it through 1.70mm sieve.
  • The sample is dried in the oven at 105-110 degree Celsius and weighted again.
  • The percentage loss is calculated by the difference between the original sample and the retained sample of aggregates. The small particles are not considered as they are the result of friction due to wear and tear and is known as abrasion value. 

Standard test methods are:

  • AASTHO T 96 and ASTM C 131
  • ASTM C 535 

A Los Angeles Testing Apparatus machine is also available with a soundproof model. The cylindrical drum is lined with some soundproofing material which cuts the sound level. The aggregates are judged on the basis of its strength, hardness, toughness, durability and shape. Better the aggregates means better is the quality of the road or highway.

Importance of Los Angeles testing test:

  • Strength and durability- The Los Angeles testing apparatus help to measure the strength, durability and quality of the aggregate. This procedure will help you to know about the toughness of the mineral aggregate and how well it will work on roads or highways.
  • Change the properties- If the results are not according to the required standards, the alterations can be made keeping the mind the sturdiness and toughness required. It will help you to maintain the quality standards of the aggregate required. The standard quality of aggregates depends upon road construction.

So abrasion test is a necessary test which should be conducted to know the reaction of the aggregate after its wear and tear. Then you can then focus on the quality control procedure to match required standards. To calculate the percentage loss, the original weight of the aggregate is deducted from the sieved aggregate weight and is expressed in the percentage form. This is expressed as the Los Angeles Abrasion Test loss value.

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