Geosynthetics in roads and pavements

INSTALLATION OF INTERLAYERS 

 

There are four basic steps in the proper 

installation of an overlay system with a 

geosynthetic interlayer. Surface preparation is 

followed by the application of the tack coat, 

installation of the geosynthetic, and finally the 

placement of the asphalt overlay.   

 

Surface Preparation 

Clean the roadway of dirt, water, oil and debris.  

Smaller cracks should be sealed. Large cracks in 

excess of 1/8 inch (3.2 mm) and potholes should 

be filled.  The surface on which a moisture 

barrier interlayer is place must have a grade 

which will drain water off the pavement. 

 

Milling of severely cracked or rutted pavement 

may be required, or a thin layer of asphalt called 

a leveling course may be applied. Sections of 

broken asphalt that move under traffic loading 

should be removed down to the subgrade and 

reconstructed.  

 

 

Sweeping is an important part of surface preparation 

 

 

Tack Coat Application and Fabric Laydown