Lean mix indicates which of the following?

• A. Insufficient mixing only.
• B. Low binder content.
• C. The mix is too wet.
• D. Indicates insufficient mixing and low binder content.

Answer: (D)

Lean mix means the asphalt concrete has too little binder relative to the aggregate. With not enough asphalt, the coating of the aggregates is poor and the mix tends to be stiffer, more prone to cracking, and less durable. This situation often points to low binder content, and it can also arise if mixing wasn’t thorough, leaving the binder unevenly distributed. That combination is why the best description is that lean mix indicates both insufficient mixing and low binder content. The other options describe only part of the issue or a different condition (being too wet), which doesn’t capture the full cause and effect of a lean mix.