ABSTRACT
A survey of subsurface drainage systems in Iowa by Ceylan et al. found that about 20% of the Jointed Plain Concrete Pavement (JPCP) drainage systems and 10% of the Hot Mix Asphalt (HMA) systems were damaged, and most of the blockages are due to tufa, sediment and soil. For the JPCP pavements the primary mode of blockage was by tufa, whereas for the HMA pavements it was by soil deposits. The use of headwall as outlet protection system for the drainage outlet systems is recommended. A survey of the results of a video inspection of the pavement drainage systems concluded that of the drainage systems that could be inspected, half were working properly and the remaining half were non-functional because of various reasons. They presented a guide for video inspection of the edgedrain and acceptance. The overall impression has been that subsurface drainage systems help to prolong the service life of pavements.
