Biaxial Geogrids


Biaxial Polypropylene Geogrids for soil reinforcement

Rigid biaxial geogrids improve the performance of aggregate base course materials supporting paved and unpaved roadway surfaces, railway ballast and Mechanically Stabilised Earth (MSE) walls and slopes. Their integrally formed structure provides lateral stability of unbounded base courses by the interlocking of granular particles into the geogrid apertures, thus improving their vertical stress distribution characteristics. The reinforcement action of polypropylene geogrids is generated by the vertical stress causing both the aggregate and geogrid to deform. Roads and railways built with PP biaxial geogrids have increased load bearing capacity, a longer service life and reduced section thickness.

Our biaxial geogrids are manufactured by extruding, punching, longitudinal and transverse stretching of polypropylene. This results in a geogrid with high flexural rigidity and high tensile modulus in both the longitudinal (MD) and transverse (TD) directions. Because polypropylene geogrids have excellent structural stability and strong mechanical interlock performance they are ideal for soil reinforcement.

The performance of unsealed and sealed roads is critically dependent on materials used. Research by the US Corps of Engineers has shown aggregate layers stabilised with PP geogrids deliver significant performance benefits to flexible road pavements and reduce surface rutting by up to 44% compared with non-stabilised aggregate. Incorporating geogrid into a road pavement could cut construction time and costs by up to 19% and delay the onset of pavement failure by controlling lateral and vertical displacement of aggregates from traffic loads. Geogrids also help to overcome shortages of quality quarried materials and natural gravels used for road construction.

Biaxial Geogrid Applications
  • Base reinforcement – reduced lateral spreading of the base course
  • Subgrade reinforcement – increased confinement leading to stiffer base
  • Slope reinforcement
  • Road pavements
  • Mechanically Stabilised Earth embankment stabilization

Biaxial polypropylene geogrids are available with the following tensile strengths:
15/15kN/m   20/20kN/m  25/25kN/m  30/30kN/m   40/40kN/m   45/45kN/m   50/50kN/m

Composite Geogrids

Structure of a composite biaxial geogrid


Product AL AT WLR WTR tLR tTR tJ
GG1515 36 36 2.6 2.6 1.0 0.8 3.1
GG2020 35 35 2.6 2.6 1.5 1.1 3.5
GG2525 34 34 2.8 2.8 1.8 1.4 4.2
GG3030 34 34 3.0 3.0 2.5 1.5 4.9
GG4040 33 33 3.0 3.0 3.4 2.1 5.5
GG4545 32 32 3.1 3.1 4.1 2.2 5.6
GG5050 30 30 3.1 3.1 4.3 2.5 5.8


Biaxial PP Geogrid GG20

Index Properties Test Method Units MD Values TD Values
Polymer PP
Minimum Carbon Black ASTM D 4218 % 2
Tensile Strength @ 2% Strain ASTM D 6637 kN/m(lb/ft) 7(480) 7(480)
Tensile Strength @ 5% Strain ASTM D 6637 kN/m(lb/ft) 14(960) 14(960)
Ultimate Tensile Strength ASTM D 6637 kN/m(lb/ft) 20(1,370) 20(1,370)
Strain @ Ultimate Strength ASTM D 6637 % 13 13


Structural Integrity
Junction Efficiency GRI GG2 % 93 93
Flexural Rigidity ASTM D 7748 mg-cm 750,000
Aperture Stability COE Method m-N/deg 0.50


Aperture Dimensions mm(in) 35(1.4) 35(1.4)
Minimum Rib Thickness ASTM D 1777 mm(in) 1.5(0.06) 1.1(0.04)
Roll Width m(ft) 3.95(12.9) or 5.95(19.5)
Roll Length m(ft) 50(164)

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