Los Angeles Abrasion test | Test for road aggregates

Tuesday, October 3, 2017 18:03
Posted in category Transportation Engineering
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Los Angeles Abrasion test | Test for road aggregates

Los Angeles abrasion test is used to check the hardness of the aggregates.

Procedure for Los Angeles Abrasion test 

  • The apparatus consists of a hollow steel drum where internal diameter is about 28 inches.
  • Weight of the drum should be 5 kg to 10 kg.
  • The drum is supported on a shaft.
  • Then put a specified number of steel spheres in the drum.
  • The drum is then rotated by some mechanical means.
  • Speed of rotation should be 32 to 33 rounds per minute for a specific time.
  • At the end, check that how much material is converted into powder.
  • Take this material out of the machine.
  • Sieve the material from #12 US Sieve.

Los Angeles abrasion value will be
L.A.A.V= (Fines/Sample)x100

  • Higher the Los Angeles abrasion value, more weaker will be the material.
  • Lower value shows that the aggregates are stronger.

Standard Values

  • By AASHTO for base and sub base materials, L.A.A.V should not be more than 40%.
  • By other agencies, L.A.A.V should not be greater than 50%.
  • For wearing surface, standards are much more strict, because wearing surface is directly contacted to the movement of vehicles.
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