Aggregate Testing – function of the Los Angeles abrasion machine The Los Angeles abrasion (commonly misspelled “Log Angles”) machine is used to determine which property of aggregates?

Introduction / Context:
Aggregates in pavements and concrete are subjected to rubbing, grinding, and impact during service. Laboratory tests simulate these actions to predict performance. The Los Angeles abrasion machine is a standard apparatus for assessing aggregate resistance to wear under combined abrasion and impact.

Given Data / Assumptions:

• Standard charge of steel balls and prescribed number of drum revolutions.
• Specified gradation and mass of aggregate test sample.
• Result reported as percentage wear (loss) after the test.

Concept / Approach:

The test measures the reduction in mass due to breakdown of aggregate particles subjected to abrasion and impact inside the rotating drum. A lower percentage loss indicates higher abrasion resistance and better suitability for high-traffic pavements and high-wear concrete surfaces.

Step-by-Step Solution:

Verification / Alternative check:

Other tests include aggregate crushing value (ACV) for compressive crushing resistance, aggregate impact value (AIV) for impact toughness, and water absorption for porosity—distinct from LA abrasion.

Why Other Options Are Wrong:

Options A, B, and D refer to different standardized tests; “None” is incorrect because LA abrasion specifically addresses wear resistance.

Common Pitfalls:

Confusing abrasion with impact strength; selecting aggregates based on a single property instead of a balanced suite of tests.

Final Answer:

Abrasion resistance (wear)