Combigrid^® Geocomposite

Combigrid^® is a geogrid–nonwoven composite that combines four functions: reinforcement, stabilisation, separation, and filtration. It consists of a high-strength Secugrid^® geogrid integrally bonded to a needle-punched Secutex^® nonwoven geotextile. Installed between weak subgrade and base course, it reinforces the soil, stabilises the aggregate layer, prevents intermixing of fine subgrade particles with the base course, and maintains water permeability for effective drainage.

Pricing is project-specific and depends on factors such as quantity, selected grade, and delivery location. However, overall project savings are typically significant: sub-base thickness reductions of 20 – 50% compared to unreinforced designs are common. For accurate pricing, contact Naue via the contact form below for a project-specific quotation.

Secugrid^® is a standalone geogrid designed for reinforcement and stabilisation, typically used on subgrades with CBR values above 3%. Combigrid^® combines this reinforcement function with an integrated Secutex^® nonwoven geotextile, providing additional separation and filtration. Combigrid^® is therefore specified for very soft subgrades (CBR < 3%) or in applications where both a geogrid and a geotextile would otherwise be required.

PP (Q1, GRK 4C): Tensile strengths from 20/20 to 60/60 kN/m. Standard solution for most infrastructure applications, compliant with German GRK robustness class requirements.

PET (Q6 R156 C): Tensile strengths from 30/30 to 80/80 kN/m. Includes verified long-term design strength (TD) in accordance with EBGEO and approvals such as BBA/HAPAS. Maximum creep strain ≤ 0.50%. Typically specified for permanent and heavily loaded structures.

Documented reductions in sub-base thickness typically range from 20 - 50% compared to unreinforced designs. Project examples include:

• Espelkamp (Germany): 140 truckloads of fill eliminated and a 25 cm reduction in sub-base thickness, resulting in savings of approximately €10,000
• Blenheim Lake Restoration (UK): 20% reduction in aggregate use
• Redlands Farm Solar Park (UK, 2014): 30% aggregate saving

CO₂ savings are directly linked to the reduced material volume and transport requirements and therefore vary by project. Verified life-cycle assessment data is available in the Environmental Product Declaration (EPD).

Yes. After decommissioning of a haul road or working platform, Combigrid^® can be removed cleanly. The integrated nonwoven geotextile maintains effective separation between aggregate and subgrade, allowing the aggregate to be recovered with minimal contamination. For example, at Dogger Bank Wind Farm (UK), the recovered aggregate was washed and successfully resold to local suppliers.

Combigrid^® is supported by a comprehensive set of certifications and verified performance documentation:

• CE marking for stabilisation in accordance with the relevant European Technical Assessment (ETA)
• CE marking for reinforcement based on Harmonised European Standard (hEN)
• BBA certification (e.g. certificate no. 14/H218 for applicable grades) for use in the UK
• ISO 9001 certified quality management system
• Assessment of conformity in accordance with DIN 18200
• Environmental Product Declaration (EPD) providing verified life-cycle data for sustainability assessments
• Performance testing including cyclic behaviour (e.g. ASTM D7556)

Yes. The EPD provides verified life-cycle assessment data covering raw material extraction, manufacturing and end-of-life. Essential for BREEAM, LEED, DGNB. For EU public-sector tenders, EPD availability is increasingly mandatory.

Combigrid^® complies with GRK 4C. It can be installed in all weather conditions, including rain and on wet subsoils.

Combigrid^® is designed for high installation robustness, even under demanding site conditions with coarse and angular aggregates. Robustness is verified through standardised installation damage testing, like e.g. EN ISO 10722.

All grades: 4.75 m width x 100 m length (475 m² per roll, approx. 180 kg). Exception: the DB/HPQ variant for Deutsche Bahn railway projects is supplied in 4.75 m x 50 m rolls.

Primary test standard: EN ISO 10319 (tensile strength). Installation damage: EN ISO 10722. Creep: EN ISO 13431. Cyclic tensile modulus: ASTM D7556. Design standards: Eurocode 7 (Europe), EBGEO (Germany), BS 8006 (UK), AASHTO (North America). Quality: ISO 9001, DIN 18200.

Designed for weak subsoils with CBR below 3 %. Also specified on stronger subsoils where separation and filtration are needed, e.g. recycled aggregate base courses or railway rehabilitation.

Yes. Naue offers comprehensive design support for Combigrid^® applications, including grade selection, design optimisation, and specification assistance. Using tools such as the Naue Platform, Naue Paved & UnPavedRoad design calculators in the Naue Portal, engineers can determine required layer thicknesses, appropriate product grades, and potential cost savings based on established methods (e.g. BR470, AASHTO ‘93).

Naue’s engineering team also provides project-specific assessments and designs on request, ensuring technically sound and economical solutions tailored to site conditions. Get in touch via e-mail to info@naue.com or using the project request form below.