SIGMA manufactures and exports geogrid from Shandong, China — five constructions covering the main load cases: PP biaxial for subgrades, uniaxial for walls, fiberglass for asphalt, warp-knitted polyester for long-design-life structures, and steel-plastic composite for soft ground. Below: the five products, a side-by-side comparison, and where each one belongs.
A geogrid is a flat, open mesh installed within or under a soil layer to carry tension. Compacted aggregate strikes into the apertures of the geogrid mesh and locks there, so the fill can no longer spread sideways under load — the layer behaves as a stiffer slab and spreads pressure over the weaker soil below. That is the whole product in one sentence: a geogrid reinforces. It does not separate soil layers (a geotextile does that), drain water (a geonet does), or confine loose stone at the surface (that is a cellular gravel grid, a different product buyers often mix up with this one).
We supply five constructions. PP biaxial geogrid is punched and drawn in both directions, for subgrades and working platforms. Uniaxial geogrid is drawn one way, with its strength concentrated along the roll for walls and slopes. Fiberglass geogrid goes between asphalt layers to control reflective cracking. Polyester geogrid is a warp-knitted PET grid with published long-term design strength for reinforced-soil structures. Steel-plastic geogrid puts steel wire inside welded polyethylene straps for soft ground where settlement governs. A plastic geogrid — the PP and HDPE types — covers most soil reinforcement work; glass fibre and PET take over inside pavements and in structures designed for a century. The full sorting logic, type by type, is in geogrid types explained.
Figures are taken from the datasheets published on each product page; the full property tables and test methods are there.
| PP biaxial | Uniaxial (PP / HDPE) | Fiberglass | Polyester (PET) | Steel-plastic | |
|---|---|---|---|---|---|
| Material | Polypropylene, punched and drawn both ways | PP or HDPE, drawn in the machine direction | Alkali-free glass fibre, bitumen coated | Warp-knitted PET yarn, PVC / SBR / bitumen coated | Steel wire core in a polyethylene sheath, welded junctions |
| Load direction | Both directions (MD = CD) | One direction (along the roll) | Both directions (warp = weft) | Uniaxial range; knitted biaxial grades available | Biaxial (GSZ) and uniaxial (GDZ) ranges |
| Typical use | Road subgrade, base courses, working platforms | Retaining walls, MSE walls, reinforced slopes | Asphalt overlays — reflective crack control | MSE walls, steep slopes, basal reinforcement | High fills on soft ground, bridge approaches, cold regions |
| Key figures | 15-15 to 50-50 kN/m; junction efficiency 93% | PP 60–300 kN/m, HDPE 60–200 kN/m; RF_cr 2.23 at a 114-year design life | 25–120 kN/m; elongation at break ≤ 4% | Ultimate 60–800 kN/m; LTDS 34–452 kN/m at a 120-year design life | Biaxial 30-30 to 120-120 kN/m; elongation ≤ 3%; frost resistance −35 °C |
Most of what we export is geogrid for roads. A single biaxial layer at the subgrade interface raises bearing capacity, cuts rutting and lets a thinner base course do the same job: grades 15-15 and 20-20 suit light access roads and car parks, 30-30 is the common highway grade, and 40-40 to 50-50 go under heavy axle loads and container yards. As geogrid for road stabilization on high fills and bridge approaches, the steel-plastic composite earns its cost — it reaches useful tensile force at under 3% strain, before settlement shows at the surface. On soft or fine-grained ground, pair the grid with a separation fabric: woven geotextile below where the separator must carry load, nonwoven geotextile where filtration matters more. The mechanism, layer by layer, is in geogrid for road subgrade stabilization.
A geogrid retaining wall resists earth pressure as a mass, not as a face: horizontal layers of grid tie the facing blocks to a much larger reinforced soil block behind them. The workhorse is uniaxial geogrid — PP to 300 kN/m, HDPE to 200 kN/m with a creep reduction factor of 2.23 published for a 114-year design life — while the warp-knitted polyester grades carry long-term design strengths from 34 to 452 kN/m at a 120-year design life for MSE walls and bridge abutments. The same uniaxial and PET grids let a reinforced slope stand steeper than its soil would allow unreinforced. Strength grade, layer spacing and embedment length come from the wall design, not from a catalogue; the sequence, and the mistakes that bring walls down, are in geogrid retaining wall design and installation.
Send the design tensile strength (or the grade name), the total area and the destination port, and we return an ex-works, FOB or CIF price with a container loading plan — for standard grades, the same business day. If the specification only says "geogrid", start from the table above and the product page closest to your application, or send the drawings and we will propose a grade for your engineer to confirm. What actually drives the price per square metre — polymer, grade, roll size and how many square metres fit a container — is set out in the geogrid price guide.
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 PP and HDPE uniaxial geogrid for retaining walls, MSE walls and reinforced slopes — 60–300 kN/m machine-direction strength, long oval apertures, low creep.
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.
Geogrid Steel-cored composite geogrid welded at every crossing.
Start from the job, not the material. Under a road, yard or working platform: a biaxial grid. Behind a retaining wall or inside a steep slope: a uniaxial or polyester grid. Between asphalt layers: fiberglass. On soft ground where settlement governs: the steel-plastic composite. The comparison table above gives the material and key figures for each type, and every product page carries the full datasheet.
By load direction. Wheel loads on an area arrive from every direction, so road subgrades, parking yards and platforms take a biaxial grid, drawn both ways with square apertures. Reinforcement behind a wall face or inside a slope pulls in one direction only, so it takes a uniaxial grid, drawn one way with its strength along the roll. Using one where the other belongs wastes strength in the wrong axis.
On soft or fine-grained subgrades, yes. The grid reinforces; it does not separate. Without a separation layer, fines pump up into the granular fill and the stabilized layer loses strength over time. The usual build is fabric below for separation and filtration, grid above for reinforcement — a woven geotextile where the separator itself must carry load, a nonwoven where filtration and drainage matter more.
Price follows polymer and grade — a 15-15 biaxial carries far less material than a 50-50, and steel-cored grades track the steel market — so there is no honest single figure per square metre. We quote ex-works, FOB or CIF by area against the grade and quantity. Send those plus the destination port and we will come back with a price and a container loading plan.
Send the grade or the design tensile strength, the total area, any roll-width preference and the destination port. For standard grades we return a priced offer with a container loading plan the same business day. Made-to-order widths, high-strength grades and third-party testing are confirmed with the mill before we commit to a delivery date, so the offer you receive is one we can hold.
