What is the maximum tolerance for the compacted subgrade of asphalt paving as per the alignment and grade plans?

The maximum tolerance for the compacted subgrade of asphalt paving as per the alignment and grade plans is typically set at +6mm. This standard is based on the need for ensuring that the subgrade is adequately compacted and aligned to support the asphalt layer above it, providing a stable base that can withstand the loads and stresses that will be applied during its service life.

Maintaining a maximum tolerance of +6mm helps to minimize deviations from the specified grades, which can influence drainage patterns, surface smoothness, and ultimately the performance and longevity of the asphalt pavement. If the subgrade exceeds this tolerance, it may lead to issues such as uneven settlement, cracking, or poor drainage, which can significantly impair the quality and durability of the paving project.

In professional practice, the selection of this tolerance is informed by industry standards and guidelines, which strive to ensure a high quality of construction, safety, and performance for asphalt pavements.