NICET - Highway Construction Inspection Practice Exam

What type of rock aggregate is referred to as "dense graded"?

1. A mechanically crushed rock aggregate with mixed sizes

2. A natural aggregate directly from quarries

3. A lightweight aggregate for use in low-load situations

4. A uniformly sized aggregate for consistent application

The correct answer is: A mechanically crushed rock aggregate with mixed sizes

The type of rock aggregate referred to as "dense graded" is characterized by a mixture of different sizes of mechanically crushed rock. In this context, "dense graded" means that the aggregate is composed of various particle sizes, which allows for efficient packing and minimal voids when the aggregate is used in construction. This mixture helps achieve a solid and stable material that improves the overall performance of concrete or asphalt. Dense graded aggregates are essential in applications where durability, structural integrity, and load-bearing capacity are critical. The combination of sizes allows the smaller particles to fill the gaps between larger particles, resulting in a denser and robust assembly. This grading is quite favorable for various construction needs, particularly in highway construction, where the strength and stability of the surface material are paramount. Other options present aggregates that may not exhibit the same properties as dense graded aggregates. Natural aggregates may not provide the same benefits in packing efficiency as those that are mechanically crushed and mixed. Lightweight aggregates serve a specific purpose in minimizing weight, which is not the focus with dense graded aggregates. Uniformly sized aggregates may lack the compaction characteristics needed for creating a dense and stable product.