SIGMA uniaxial geogrid is extruded, punched and then drawn in the machine direction only, so the polymer chains orient along the pull and the sheet opens into long oval apertures. That single-direction draw is what gives the product its high tensile capacity and low creep along the roll — the two properties a geogrid reinforced retaining wall, a steep reinforced slope or a soft-subgrade embankment is designed around. Two ranges are produced: a polypropylene range from 60 to 300 kN/m, and an HDPE range from 60 to 200 kN/m punched from solid sheet, with a published creep dataset for long design lives. Rolls are 1–3 m wide in 50 m and 100 m lengths.
A uniaxial geogrid is a polymer sheet that has been extruded, punched with a regular pattern of holes and then drawn in the machine direction alone. Stretching the sheet one way aligns the molecular chains along the pull and stretches each hole into the long oval aperture that identifies the product. The result is a grid that carries a very high tensile load along the roll with little elongation and little long-term creep, and only a nominal load across it. That is exactly the load pattern in a reinforced soil mass, where every layer is pulling back against the earth pressure behind the face.
The largest use is geogrid for retaining wall construction. Layers are laid horizontally into the compacted backfill and connected at the facing, tying the block or panel face to a much larger reinforced soil block behind it. Building a retaining wall with geogrid turns a facing that would topple under earth pressure into a gravity structure that resists it as a mass. The same principle governs an MSE wall geogrid layout behind precast panels, a segmental block wall, and a bridge abutment fill. Strength grade, layer spacing and embedment length are set by the design engineer for the specific wall height, backfill and surcharge — we supply the grade the design calls for, we do not set it.
The polypropylene range runs 60, 80, 110, 150, 200, 260 and 300 kN/m, with tensile strength at 2% strain from 17 to 105 kN/m and yield elongation not more than 10%. Apertures are 530 × 14 mm across all grades, with rib and junction thickness increasing with strength. The HDPE range is punched from solid sheet and drawn to 60, 80, 120, 160, 180 and 200 kN/m, with 460 × 12 mm apertures, 11.5% elongation at ultimate load and junction efficiency of 90–93% to GRI GG2-87. HDPE is the range to specify where a long design life has to be demonstrated, because its durability data is published rather than assumed.
Long-term behaviour, not short-term break load, decides how much of a grid a wall designer can actually use. On the HDPE range the creep reduction factor RF_cr measured to ASTM D5262 is 2.23 for a 114-year design life, the installation damage reduction factor RF_id to ASTM D5818 is 1.00, oxidation resistance to EN ISO 13438 is 100%, and 98% of strength is retained after UV exposure to ASTM D4355. Those figures belong together — the 2.23 only means anything alongside the 114-year design life it was derived for. A geogrid reinforced soil structure that has to stand for a century needs numbers of this kind in the submittal, and they are the reason the HDPE range exists next to the PP one.
Beyond walls, uniaxial grid is used for geogrid slope stabilization: layers built into a fill let a slope stand far steeper than its soil would allow unreinforced, saving footprint on a constrained site. Specifying geogrid for slopes also spreads load over soft or compressible subgrade under embankments, dykes and levees. Where the face has to be vegetated rather than hard-faced, the reinforcement is often combined with a surface layer such as our 3D reinforced geomat, and with woven geotextile or nonwoven geotextile for separation and drainage behind the reinforced zone. For toe protection and scour-prone bases, geobags are used alongside.
Geogrid retaining wall installation follows the same sequence on every job: level and compact the fill, roll the grid out with the machine direction running back into the fill and perpendicular to the face, connect or lap it at the facing course, then place and compact the next lift over it without turning tracked plant directly on the exposed grid. Crews installing geogrid should keep rolls out of prolonged sunlight before cover and never stretch a layer to correct alignment. For traffic platforms and haul roads where load comes from every direction, a biaxial geogrid is the correct choice instead; for asphalt overlays see fiberglass geogrid, and for high-strength flexible options polyester geogrid and steel-plastic geogrid. As the manufacturer we quote geogrid price ex-works per square metre against grade, width and quantity — send the strength grade and area and we will come back the same business day. The full range is on our products page.
PP uniaxial geogrid — primary strength ladder. Test method ASTM D6637 where stated by the source. Values verbatim from the source datasheet.
| Property | Unit | 60 | 80 | 110 | 150 | 200 | 260 | 300 |
|---|---|---|---|---|---|---|---|---|
| Tensile strength (MD) | kN/m | 60 | 80 | 110 | 150 | 200 | 260 | 300 |
| Tensile strength @ 2% strain | kN/m ≥ | 17 | 26 | 32 | 45 | 70 | 94 | 105 |
| Tensile strength @ 5% strain | kN/m ≥ | 35 | 48 | 64 | 90 | 120 | 185 | 195 |
| Yield elongation | % ≤ | 10 | 10 | 10 | 10 | 10 | 10 | 10 |
| Roll length | m | 100 | 100 | 50 | 50 | 50 | 50 | 50 |
| Roll width | m | 1–3 | 1–3 | 1–3 | 1–3 | 1–3 | 1–3 | 1–3 |
Mainly reinforced soil structures that pull in one direction: geogrid reinforced retaining walls, segmental block walls, MSE walls behind precast panels, steep reinforced slopes, bridge abutment fills, and embankments over soft ground. Because it is drawn in the machine direction only, its strength is concentrated along the roll — the direction a reinforcement layer is loaded.
Uniaxial geogrid is drawn one way, has long oval apertures and carries high load along the roll only. Biaxial geogrid is drawn both ways, has square or rectangular apertures and carries load in both directions. Use uniaxial where reinforcement pulls back from a face or slope; use a <a href="/biaxial-geogrid/">biaxial geogrid</a> under roads, yards and working platforms where wheel loads come from every direction.
That is a design decision, not a catalogue lookup. Wall height, backfill properties, groundwater, surcharge and facing type determine the required long-term design strength, layer spacing and embedment length, and the design engineer sets them. Send us the grade and layout the design specifies — PP from 60 to 300 kN/m, HDPE from 60 to 200 kN/m — and we will supply and document it.
Layer count and vertical spacing come out of the wall design, not from a rule of thumb. In practice layers are tied to the facing course height so each one lands on a block joint, and spacing tightens toward the base where earth pressure is highest. Give us the spacing from your drawings and we will confirm roll lengths and the number of rolls per layer.
The HDPE uniaxial range does. Its creep reduction factor RF_cr is 2.23 for a 114-year design life to ASTM D5262, with an installation damage reduction factor of 1.00 to ASTM D5818, 100% oxidation resistance to EN ISO 13438 and 98% strength retained after UV exposure to ASTM D4355. These are supplier-published typical values from a single source; we can arrange third-party testing where a project requires certified data.
Level and compact the fill, roll the grid out with the machine direction running back into the fill perpendicular to the wall face, connect or lap it at the facing course, pull it hand-taut without stretching, then place and compact the next lift over it. Keep tracked plant off the exposed grid and cover it promptly. Follow the wall designer’s drawings for embedment length, spacing and overlaps.
PP covers the wider strength range, up to 300 kN/m, and is the usual choice for general wall and slope work. HDPE tops out at 200 kN/m but carries a lower strain at ultimate load and a published creep and durability dataset, which is what a submittal for a very long design life needs. Tell us the specification and design life and we will point you to the right one.
Geogrid price depends on the strength grade, polymer, roll width and order volume, so there is no single figure per square metre. We are the manufacturer and quote ex-works by area against your grade and quantity, with FOB or CIF available. A 40HC holds 55,000 m² of the 60 kN PP grade down to 8,000 m² of the 260 kN grade, which is what drives delivered cost on export orders.
Tell us quantity, destination port, and any questions — we reply within one business day.
Geogrid Punched and drawn PP biaxial geogrid for subgrade stabilization and base reinforcement — 15-15 to 50-50 kN/m grades, square apertures, 93% junction efficiency.
Geogrid Bitumen-coated fiberglass geogrid for asphalt overlays — warp-knitted alkali-free glass fibre, 25–120 kN/m, elongation ≤ 4%, standard and self-adhesive.
Geogrid Warp-knitted PET geogrid with published long-term design strength — 34 to 452 kN/m LTDS at a 120-year design life, PVC, SBR or bitumen coated.
