ABSTRACT
Precipitation, in the form of rain and snow, may result in accumulation of water on the surface, and find its way through joints and cracks inside a pavement structure. Water can also enter the subgrade soils through capillary action from a nearby water table. Water puddles or films on the surface, especially in ruts, can cause unsafe driving conditions through hydroplaning and skidding of vehicles, whereas water inside the pavement structure can result in deterioration of the mixtures and materials. If frost-susceptible soils are present, ice lenses can form due to freezing temperatures in the winter, causing heaves. And then thawing in the spring causes loss of support and consequent cracking on the surface. The sources and effects of water are summarized in Figure 6.1.
