Test Name: Los Angeles Abrasion (LAA) Test
Test Code: AASHTO T-96/ASTM C-131
Question: Why Los Angeles Abrasion (LAA) Test is necessary?
Natural aggregates undergo a lot of physical change in its entire life. Since its formation to the final use in construction, the aggregate may undergo a significance change in its shape,its color,toughness and hardness. During handling and transportation of aggregates the aggregates may crush if the quality is not good. Therefore it is very much needed to determine the hardness of aggregates against a substantial abrasion continuing over it. That’s why LAA test is very important to determine the quality of aggregate.
Question: What is the reference test code?
Los Angeles Abrasion (LAA) Test is found on almost all of the standard test codes. It is well described in AASHTO T-96 ans ASTM C-131 code.
Question: What are the aggregate sizes for LAA?
There are four sizes of aggregates that can be tested on standard Los angeles macine. The sieve sizes are and data sheet for Los Angeles Abrasion Test are
|Grade||No, of Charge||Sieve Size mm||Designated Fractional Weight (gm)||Total mass (gm)||Wt., of Charge (gm)|
|1250± 251250± 25
|5000 ± 10||5000 ± 25|
|B||11||19.0-12.512.5-9.5||2500 ± 102500 ± 10||5001 ± 10||4584 ± 25|
|C||8||9.5-6.36.3-4.75||2500 ± 102500 ± 10||5002 ± 10||3330 ± 20|
|D||6||4.75-2.36||5000 ± 10||5003 ± 10||2500 ± 15|