The correct answer is A. 0.4 %.
Water absorption is the amount of water that an aggregate can absorb when submerged in water. It is a measure of the aggregate’s porosity and is an important factor in determining its suitability for road construction.
Aggregates with high water absorption can be problematic in road construction because they can absorb water from the surrounding soil and become saturated. This can lead to a number of problems, including:
- Reduced strength: Saturated aggregates are weaker than dry aggregates. This can lead to problems with the stability of the road surface.
- Increased frost heave: When water freezes, it expands. This expansion can cause saturated aggregates to heave, which can damage the road surface.
- Increased cracking: When water freezes, it can also cause aggregates to expand and contract. This expansion and contraction can lead to cracking in the road surface.
For these reasons, it is important to use aggregates with low water absorption in road construction. The maximum limit of water absorption for aggregate suitable for road construction is 0.4%. This means that an aggregate should not absorb more than 0.4% of its weight in water.
Option B, 0.6%, is too high. Option C, 0.8%, is also too high. Option D, 1.0%, is the highest of the options and is definitely too high.