Stabilisation and reinforcement of paved roads involves the integration of geosynthetic layers - typically geogrids or composite geosynthetics - into the unbound base or subbase course of a road to extend its service life and reduce maintenance costs. Repeated traffic loading causes progressive rutting, reflective cracking and structural fatigue in unreinforced pavements. Secugrid® and Combigrid® geosynthetics from Naue distribute loads more effectively, reduce strain in the pavement structure and prevent premature failure.
Naue geosynthetic solutions perform in every scenario where structural pavement life, load capacity and economic efficiency are critical.
Reinforced base courses for heavily trafficked motorways and roads subject to bus loads, and variable subgrade conditions.
Stable paved surfaces for HGV and forklift traffic at warehouses, ports and industrial estates on variable or weak subgrades.
Geogrid layer beneath base or subbase course prevents reflective cracking from propagating up to the new surface course.
Geosynthetic reinforcement reduces the impact of freeze-thaw cycles on base course integrity and minimises post-frost maintenance.
Paved road projects demand products that perform reliably under demanding site conditions. Secugrid geogrids and Combigrid composite geosynthetics are designed to withstand the rigours of installation: High mechanical stresses during placement and compaction of aggregate. The monolithic robust polypropylene flat bars of Secugrid and Combigrid resist installation damage and maintain structural integrity throughout the pavement life.
The design of geosynthetic systems for paved roads follows recognised national and international standards. The Naue Portal’s PavedRoad - AASHTO Pavement Design Calculator allows engineers to determine the optimum geosynthetic solution quickly, in compliance with standards and with full auditability.
The following system benefits come directly from how the Naue products work within the layer structure:
Practical advantages for site crews:
In many paved road projects, stabilisation and reinforcement alone does not guarantee long-term structural integrity. When the subgrade contains fine particles (silts, clays or mixed soils), these fines can migrate upward into the coarse granular base course under cyclic traffic loading. This process, known as subgrade fouling, progressively reduces the drainage capacity and structural stiffness of the base course, accelerating failure.
Ideal for: CBR < 3% with filtration need, two-stage design.
Ideal for: CBR < 3% where stabilisation / reinforcement and fines control are required simultaneously.
Key rule: Stabilisation and reinforcement improve structural capacity. Separation and filtration preserve that capacity and maintain drainage efficiency of the aggregate over the long term.
Product selection depends on subgrade conditions, design requirements, construction programme and whether separation and filtration are required alongside stabilisation and reinforcement.
| Criterion | Secugrid® | Secugrid® + Secutex® | Combigrid® |
|---|---|---|---|
| Subgrade CBR | CBR ≥ 3% | CBR < 3% (two-product option) | CBR < 3% (preferred single layer option) |
| Stabilisation / reinforcement | Yes — primary function | Yes | Yes - via geogrid component |
| Separation / filtration | No | Yes - via separate Secutex® nonwoven geotextile | Yes - via factory-integrated Secutex® |
| Construction speed | Standard | Low (two layers to handle) | High - single-layer installation |
| Typical application | New highway base course | Weak subgrade and filtration, two-stage design | Road rehabilitation, logistics parks |
| Design tool | Naue Portal AASHTO Calculator, Naue PavedRoad (Bearing Capacity) | Naue Portal AASHTO Calculator; Naue PavedRoad (Bearing Capacity) | Naue Portal AASHTO Calculator; Naue PavedRoad (Bearing Capacity) |
These benefits come directly from how the Naue products work in this solution, and what they mean in practice for your project.
Longer service life with less maintenance
Geosynthetic stabilisation and reinforcement reduces rutting and reflective cracking under repeated traffic loading. research Institutes report extended rehabilitation cycles and lower whole-life costs compared with unreinforced designs.
Significant cost savings vs. conventional design
Geogrid stabilisation and reinforcement enables a base course thickness reduction of up to 50 %. On a standard 1,000 m road section, the geosynthetic solution has demonstrated savings of more than EUR 100,000 compared with conventional excavation and aggregate replacement (source: Naue cost comparison study).
Fast and simple installation
Secugrid® and Combigrid® rolls unroll directly onto the prepared subgrade and are immediately covered with aggregate. No specialist equipment is required. Combigrid® eliminates the need for a separate geotextile layer, saving time and reducing.
Verified performance by independent research
Field trials conducted by the US Federal Highway Administration (FHWA) confirmed that welded geogrids such as Secugrid® and Combigrid® exhibited the highest resistance to rutting of all products tested on unpaved roads. AASHTO M-E design approach compatibility ensures acceptance by road authorities in the US and beyond.
Stabilisation and reinforcement in paved roads involves the integration of geosynthetic layers - such as Secugrid® geogrids or Combigrid® geocomposites - into the base or subbase course of a road. The geosynthetic distributes axle loads, reduces rutting and prevents reflective cracking, extending pavement service life and reducing maintenance expenditure.
Specify Secugrid® where only stabilisation and reinforcement are required and the subgrade CBR is at or above 3 %. Specify Combigrid® where the subgrade CBR is below 3 % and separation or filtration is also needed. Combigrid® combines all four functions in a single layer, simplifying installation and reducing construction time.
Key standards include AASHTO 1993 and the AASHTO Mechanistic-Empirical Pavement Design Guide (MEPDG) (US and international); EBGEO (Germany); BS 8006-1 (UK); RStO and ZTV E-StB (Germany). Naues Portal’s PavedRoad - AASHTO Calculator incorporates the AASHTO 1993 design methodology. For project-specific designs, contact Naue’s Engineering & Design Department (EDD).
On a 1,000 m road section, the geosynthetic stabilised and reinforced solution has been shown to save more than EUR 100,000 compared with conventional aggregate excavation and replacement (source: Naue cost comparison study).
The prepared subgrade is graded and levelled. The Secugrid® geogrid or Combigrid® roll is unrolled directly onto the subgrade, with a typical minimum 300 mm overlap at longitudinal and transverse joints. Aggregate base course is then placed and compacted over the geosynthetic using standard equipment. No specialist tools are required. Combigrid® eliminates the installation of a separate geotextile.
By extending the service life of the road, geosynthetic stabilisation and reinforcement can reduce the frequency of rehabilitation cycles and decrease asphalt waste. Naue geosynthetics are manufactured in ISO-certified facilities and support circular construction principles.
Yes. The AASHTO Mechanistic-Empirical design guide explicitly incorporates geosynthetic reinforcement parameters. FHWA-published WTI research validated Secugrid® and Combigrid® performance in field conditions. In Europe, EBGEO (Germany) and BS 8006-1 (UK) provide design frameworks. Naue can provide product data in formats required by all major national approval bodies.
Secugrid® and Combigrid® have been used in thousands of paved road projects globally for decades, from national highways in North America and Europe to logistics parks in Asia and rehabilitation works in the Middle East. Reference projects include Highway 21 (Saskatchewan, Canada), LRT3 Federal Route 5 (Malaysia) and frost road rehabilitation projects across northern Europe. Please also see our case studies for project references.
Western Transportation Institute (WTI) field testing published with the US Federal Highway Administration (FHWA) confirmed that welded geogrids, including Secugrid® and Combigrid®, achieved the highest rutting resistance of all products evaluated in a comparative study. This independent validation underpins AASHTO Mechanistic-Empirical design compatibility and supports acceptance by road authorities in the US, UK and Australia.
Yes. Secugrid® and Combigrid® are designed for both new-build road base courses and road rehabilitation projects.
Naue Secugrid® geogrid stabilises and reinforces roads, embankments, working platforms, slopes and walls.
Naue Combigrid® is a geogrid with integrated nonwoven geotextile that combines stabilisation, reinforcement, separation and filtration in a single installation step.
Naue Secutex® is a mechanically bonded nonwoven geotextile for separation, filtration and protection in roads, railways and hydraulic engineering projects.