are used almost entirely for soil reinforcement. Their large aperture
size limits their effectiveness as a filtration layer but their
high tensile strength make them ideal for reinforcement applications
such as base reinforcement and soft soil stabilization.
Geogrids are manufactured using application specific grades of
polyolefin resins (high-density polyethylene or polypropylene).
Depending upon manufacturing techniques and materials, geogrids
can be designed to resist creep when subjected to high loads for
long periods of time or resist high, short-term dynamic loads or
moderate loads over longer periods of time.
Uniaxial geogrids are designed to endure stress in one direction.
The ribs of this variety of geotextile tend to be thicker and the
apertures are long narrow slits. This variety of grid tends to
be stronger than biaxial, but can only be applied in situations
where stresses occur in a single direction (unless two uniaxial
grids are placed in opposite directions).
Biaxial geogrids can take stresses in two directions and their
apertures are more evenly dimensioned. They are useful in situations
where stresses are applied in two directions, but don't have as
much tensile strength in either direction as a uniaxial geogrid
does in its direction of application.