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