The property of aggregate which resists abrasive effect of hard particles or mechanism is known as
Correct Answer: B. abrasion resistance
📚 Detailed Explanation: Abrasion Resistance of Aggregate
Several different mechanical properties of aggregate are tested and specified for concrete, each addressing a different mode of load application. Abrasion resistance specifically addresses the wear mechanism — gradual surface removal by sliding, scraping, or grinding contact with hard particles or mechanisms.
Why B (abrasion resistance) is correct: Abrasion resistance is by definition the ability to resist abrasive wear. In aggregate testing, this is measured by the Los Angeles (LA) abrasion test (IS 2386 Part IV), where the aggregate is subjected to grinding by steel balls in a rotating drum. Contrast: Toughness (Option A) = resistance to sudden impact (measured by AIV test); Hardness (Option C) = resistance to indentation or scratching (a material science property, related to LA abrasion but not identical); Durability (Option D) = resistance to weathering and deterioration over time (a broader property measured by soundness tests).
Mechanical Properties of Aggregate
| Property | Definition | Test |
|---|---|---|
| Abrasion resistance | Resistance to wear by rubbing/grinding | LA Abrasion (IS 2386 Pt IV) |
| Toughness | Resistance to sudden impact | AIV (IS 2386 Pt IV) |
| Hardness | Resistance to scratch / indentation | Mohs scale / LA abrasion (indirect) |
| Durability | Resistance to weathering | Soundness (IS 2386 Pt V) |
Key Concepts for Students
- Abrasion resistance = LA abrasion test; this is the primary association for this property.
- High abrasion resistance (low LA value) is critical for pavements, wearing courses, and heavy-duty floors where surface is exposed to traffic wear.
- Typical hard rocks (granite, basalt, quartzite) have LA values of 20–35%, making them suitable for roads.