Which of the following test measures the toughness of road aggregates? 

Explanation:

Impact test

• Purpose: Measures the toughness of aggregates — their ability to resist sudden shocks or impacts.

• Test Used: Aggregate Impact Value (AIV) test using an impact testing machine.

• Relevance: Toughness is crucial for pavement surfaces subjected to dynamic loads (e.g., from vehicles).

• Standard: As per IS 2386 (Part 4).

Additional InformationShape test

• Purpose: Determines the shape characteristics of aggregates — like flakiness and elongation.

• Tests Used:

  • Flakiness Index Test

  • Elongation Index Test

• Relevance: Well-shaped aggregates ensure better interlocking and compaction in pavements.

Crushing test

• Purpose: Measures the compressive strength or resistance to crushing under a gradually applied load.

• Test Used: Aggregate Crushing Value (ACV) test.

• Relevance: Important for assessing aggregates used in base/sub-base courses.

• Standard: IS 2386 (Part 4).

Abrasion test

• Purpose: Measures resistance to wear and tear due to friction (rubbing action).

• Tests Used:

  • Los Angeles Abrasion Test

  • Deval’s Abrasion Test

• Relevance: Critical for bituminous and concrete roads, especially in high-traffic areas.