SYNTHESIS ON SUBSURFACE DRAINAGE OF WATER INFILTRATING A PAVEMENT STRUCTURE

This paper summarizes current subsurface pavement drainage used by various state and local agencies. The paper starts with a brief introduction on moisture in a pavement and the damage it can cause. Following the introduction, the relative effectiveness of subsurface drainage is estimated based on environmental conditions, traffic levels, and physical characteristics of the pavement structure. The next three sections of the paper discuss various components used in subsurface drainage, combinations of drainage components to perform specific drainage tasks, and maintenance required to keep drainage components functioning. Next, results from a survey sent to Minnesota city and county agencies are given summarizing current drainage practices used on lower volume roads. Finally, the last part of the paper gives cost and performance data on drainage systems used by various states.