Geosynthetics in roads and pavements

 

Typical Solutions 

Most traditional drainage systems use an open-

graded drainage layer under the full width of a 

roadbed with adequate collector pipes and outlet 

pipe.  Additionally, pavement edge drains can 

be retrofitted to greatly reduce the rate of water-

related damage to existing pavements if the road 

base is reasonably free draining. 

 

The Geosynthetic Solution 

Recent moves toward greater use of subsurface 

pavement drainage stem from the development 

of improved and economical drainage materials, 

along with greater awareness of the nature and 

extent of the problem. 

 

The introduction of geotextiles into drainage 

applications has enhanced the economical 

application of blanket and trench drains under 

and adjacent to the pavement structure, 

respectively.  The excellent filtration and 

separation characteristics associated with 

filtration geotextiles permits the use of a single 

layer of open-graded base or trench aggregate 

enveloped in a geotextile.  The thin filtration 

geotextile reduces the required excavation as 

well as the cost of the drained structural section. 

 

The following enhanced performance has been 

identified for pavements having an efficient 

functioning edge drain system: 

 

Flexible Pavements:  

25% increase in service life. 

Rigid Pavements:  

50% increase in service life. 

 

 

The open-graded base course (above) ties into an edge 

drain (below).  Both are protected by geotextiles.