The question asks which factors would increase the effective specific gravity of aggregates in asphalt concrete. We need to select at least two correct answers from the given options.

1. Problem Description

The question asks which factors would increase the effective specific gravity of aggregates in asphalt concrete. We need to select at least two correct answers from the given options.

2. Solution Steps

The effective specific gravity ($G_{se}$) is calculated as:

$G_{se} = \frac{W_{dry}}{W_{dry} - (W_{sat} - W_{water})}$

Where:

$W_{dry}$ is the oven-dry weight of the aggregate.

$W_{sat}$ is the saturated surface-dry weight of the aggregate.

$W_{water}$ is the weight of water displaced by the aggregate.

$W_{sat} - W_{dry}$ represents the amount of water that the aggregate can absorb.

A. Presence of unreacted cement particles: This is not directly related to the specific gravity of aggregates in asphalt concrete. Cement is used in concrete, not asphalt concrete. Therefore, this is not a correct option.

B. Complete removal of surface moisture: Complete removal of surface moisture leads to the oven dry condition. While the effective specific gravity uses the dry weight, merely removing surface moisture won't change the amount of moisture that the aggregate can absorb. In fact, it leads to calculating the bulk specific gravity instead of effective specific gravity.

C. Partial asphalt absorption in pores: If asphalt is absorbed into the pores, it reduces the volume of water the aggregate can absorb, essentially increasing the amount of solid material without increasing the overall volume displaced by water during the specific gravity test. This makes $W_{sat} - W_{dry}$ smaller, which increases $G_{se}$. So, this is a correct option.

D. High water-permeable voids: If there are high water-permeable voids, $W_{sat} - W_{dry}$ will increase, leading to a decrease in $G_{se}$. So, this is not a correct option.

E. Use of hydrophobic coatings: Hydrophobic coatings would repel water, decreasing the amount of water absorbed, making $W_{sat} - W_{dry}$ smaller and thereby increasing $G_{se}$. Therefore, this is a correct option.

3. Final Answer

The correct answers are C and E.

Final Answer: C, E