Geosynthetics in roads and pavements

Typical Solutions 

As with unpaved roads, a problematic subgrade 

is typically excavated and replaced, or it is 

improved by the addition of cement, lime, or 

excess aggregate.  In any case, the traditional 

solution is often costly and always time 

consuming. 

 

The Geosynthetic Solution 

As was noted earlier, geosynthetics are proving 

to be a cost effective alternative to traditional 

road construction methods.  In paved roads, 

lateral restraint also called confinement is 

considered to be the primary function of the 

geosynthetic. With the addition of an 

appropriate geosynthetic, the Soil-Geosynthetic-

Aggregate (SGA) system gains stiffness.  The 

stiffened SGA system is better able to provide 

the following structural benefits: 

• 

Preventing lateral spreading of the base 

• 

Increasing confinement and thus stiffness of 

the base 

• 

Improving vertical stress distribution on the 

subgrade 

• 

Reducing shear stress in the subgrade 

 

 

 

Geogrid base reinforcement stiffens the aggregate base 

layer providing long-term support for the paved surface.