Soil stabilisation without cement and without excavation
Soil stabilisation improves the existing soil so that it forms the base course of a road itself. This page explains how the three common methods work, how they differ and which soils TERRA-3000® is suitable for.
Basics
What is soil stabilisation?
In conventional road construction, the ground is excavated down to frost depth, hauled away and replaced with crushed stone and gravel. For a road 6 m wide, that means 60 to 80 cm of excavation along the entire route.
With soil stabilisation, the soil stays where it is. It is mixed with an additive, compacted and then takes over the function of the base course itself. Excavation, haulage and a large share of new material are no longer needed.
Methods
Three methods at a glance
TERRA-3000®
TERRA-3000® is not a binder but a catalytic ion exchanger. It activates the natural binding forces of the existing soil, without cement, lime or polymer. The surface layer can be applied the next day.
Cement and lime
The binder is milled into the soil and hardens hydraulically. Lime is mainly used for wet, cohesive soils, cement for higher strength. With cement-bound base courses, the surface layer can only be applied after 7 to 28 days.
Polymer methods
A synthetic binder glues the soil grains together. Many polymer systems also use cement. In that case, cement spreaders and a multi-stage installation process are required, and the cement content also determines curing time and logistics.
| Criterion | TERRA-3000® | Cement and lime | Polymer methods |
|---|---|---|---|
| Principle | Ion exchange, compacts the existing soil | Hydraulic hardening | Bonding with a synthetic binder, often with cement |
| Cement | No | Yes, partly combined with lime | Often in addition |
| Surface layer | The next day | With cement after 7 to 28 days | Depends on system and cement content |
| Material and logistics | Solution in a tanker, transport up to 60 % lower* | Large quantities of binder, spreader | Binder, plus spreader if cement is used |
* depending on the location of the quarries. The information on cement, lime and polymer methods describes typical applications. Individual systems may differ.
How it works
How TERRA-3000® works
TERRA-3000® lowers the surface tension of the soil water and dissolves the water film around the fine soil particles. During compaction, the grains move closer together. The soil becomes denser, more load-bearing and absorbs significantly less water.
- Water and frost: The compacted layer neutralises the effects of water and frost.
- Load-bearing capacity: The permissible load is more than twice what ordinary roads require.
- Long-term behaviour: The base course becomes denser year after year. The Hollands Lane Trial Study describes the effect as permanent.
- Installation: Work can continue in rain and wind. The product is non-flammable and requires no special storage.
Suitability
Which soils TERRA-3000® is suitable for
- Cohesive and semi-cohesive soils with a high proportion of silt, fine clay or loess are directly suitable.
- Guide values: at least 25 % fines below 0.063 mm, of which 15 to 25 % clay below 0.002 mm. Plasticity index 5 to 30 %, moisture close to the optimum Proctor value.
- Sand, gravel and crushed stone can be made suitable by adding missing fine fractions such as clay or loess.
- Heavy clay soils: non-cohesive material can be added to reduce swelling.
- Desert sand: In the laboratory of FH Münster University of Applied Sciences, pure desert sand was bound under a simulated warm climate into a layer that meets the subgrade requirement.
Whether a soil is suitable is determined from a soil sample with grading curve and soil classification.
Process
Three steps on site
- Analyse the soilDetermine grain size distribution and moisture, calculate layer thickness and the required amount of TERRA-3000®.
- Mix in and compactApply the solution with a mill or sprayer, mix it thoroughly with the soil and compact with rollers of at least 20 tonnes.
- Apply the protective layerBefore the final roller pass, apply milled asphalt, stone screenings or crushed stone. Asphalt or a simple bitumen and chippings layer follows the next day.
Standard road construction machinery is required: grader with ripper, tanker with spraying device, soil stabiliser or road mill and rollers of at least 20 tonnes.
Evidence
Tested under real conditions
Hollands Lane Trial Study, Australia (2021)
Conducted by Bland Shire Council in New South Wales, funded by the NSW Government and Local Government NSW. Nine products were compared on the same unsealed test section. The TERRA-3000® section was flooded four times for up to seven days each and was exposed to rain, dry periods and vehicle traffic throughout the trial.
“Minimal fines loss and no significant deformation, even after repeated inundation.”Hollands Lane Trial Study, Bland Shire Council (2021)
Ecotoxicity and genotoxicity (2026)
The laboratory Hydrotox tested the eluate from soil treated with TERRA-3000® on algae, daphnia, fish eggs and luminescent bacteria, and for genotoxicity using the umu test (report no. 5033, January 2026). No relevant toxicity was found at any dilution level. The requirements of the German DIBt principles for assessing the effects of construction products on soil and groundwater are met.
In use worldwide
TERRA-3000® has been on the market for 30 years, is EU-certified and has been used in more than 100 projects in 18 countries, including Canada, Austria, Colombia and Australia.
FAQ
Questions about soil stabilisation
How does TERRA-3000® differ from polymer methods?
Polymer methods bond the soil with a synthetic binder and often also use cement. TERRA-3000® works without cement, lime or polymer. It activates the binding forces of the existing soil, so neither large quantities of binder nor cement spreaders are needed.
How soon can the surface layer be applied?
The next day. With cement-bound base courses it takes 7 to 28 days. Overall, construction time is reduced by a factor of two to three.
Is special machinery required?
No. A grader, tanker, soil stabiliser and rollers of at least 20 tonnes are sufficient, all standard road construction machinery.
What warranty is provided?
A 7-year warranty on roads, provided the process is followed as specified.
What does soil stabilisation with TERRA-3000® cost?
That depends on the soil, area and layer thickness. In our comparison for a base course 1,000 m long, 10 m wide and 0.6 m thick, costs are 40 to 70 % below conventional methods. We prepare a specific quotation after the soil analysis.
Where is TERRA-3000® used?
For all road categories, access roads to mining areas, rural roads, airfields, railway substructures, earth dams, embankments and building and storage areas. Also in difficult terrain such as swamps, permafrost or peat soils.
Is TERRA-3000® right for your project?
For an initial assessment, the location, length and width of the route are enough. Write to us at mail@sl-coating.com or call +49 177 8871288.