The correct answer is: 60%.
Longitudinal overlap is the amount of overlap between two successive layers of asphalt pavement. It is important to maintain a proper longitudinal overlap to ensure the integrity of the pavement. If the overlap is too small, there is a risk of cracking and other damage. If the overlap is too large, it can create voids and other problems.
The recommended longitudinal overlap is 60%. This means that the leading edge of the second layer of asphalt should overlap the trailing edge of the first layer by 60%. This overlap provides a good bond between the two layers and helps to prevent cracking.
It is important to note that the recommended longitudinal overlap may vary depending on the type of asphalt pavement and the climate. For example, in cold climates, a larger overlap may be necessary to prevent cracking.
Here is a brief explanation of each option:
- Option A: 50%. This is a common overlap used in some applications. However, it is not recommended for longitudinal overlap because it does not provide enough of a bond between the two layers of asphalt.
- Option B: 60%. This is the recommended longitudinal overlap. It provides a good bond between the two layers of asphalt and helps to prevent cracking.
- Option C: 70%. This is a larger overlap that may be necessary in some applications, such as in cold climates. However, it is important to note that a larger overlap can create voids and other problems.
- Option D: 75%. This is an excessive overlap that should not be used. It can create voids and other problems in the asphalt pavement.