Question

What are the major factors to consider when designing asphalt concrete mix?

1) Aggregate gradation and shape
2) Asphalt binder content
3) Mix temperature
4) Mixing time
5) All of the above

Answer 1

When designing asphalt concrete mix, the major factors to consider are aggregate gradation and shape, asphalt binder content, mix temperature, and mixing time.

Step-by-step explanation:

When designing asphalt concrete mix, there are several major factors to consider:

1. Aggregate gradation and shape: The size and shape of the aggregates used in the mix affect the overall performance of the asphalt concrete. Proper aggregate gradation ensures that the mix has good stability, durability, and workability.
2. Asphalt binder content: The amount of asphalt binder in the mix determines its strength, flexibility, and resistance to cracking. The correct binder content is crucial for achieving the desired performance.
3. Mix temperature: The temperature at which the mix is produced and placed affects its workability and compactability. The mix temperature must be carefully controlled to ensure proper compaction and achieve the desired density.
4. Mixing time: The duration of mixing affects the overall homogeneity and workability of the mix. Sufficient mixing time is necessary to achieve a uniform distribution of asphalt binder and aggregates.

Therefore, the correct answer is 5) All of the above.