Because asphalt cures as it cools and dries it becomes harder over time. In most instances, excavation of the sub-base is standard procedure before the paving process can be completed. In some cases both excavation and paving can be accomplished on the same day, however, this depends on the size of the project and the existing weather conditions at the site. The compacting stage is probably one of the most important aspects of any paving project. When compacting is done correctly it is designed to prevent the sinking of asphalt and crumbling. As such, the stage is essential to get right.