Carbon and Land-Use Impacts: Cement-Stabilised Ground vs. Aggregates

Carbon Emissions from Cement-Based Stabilisation 

In-situ ground stabilisation using cement involves mixing the existing soil or subgrade with a binding agent (usually cement or a cementitious mix) to improve its strength, durability, and load-bearing capacity. 

The challenge here is cement’s massive carbon footprint: 

• Manufacturing 1 tonne of cement releases about 0.8–1 tonne of CO₂, largely because of:
  • The chemical reaction in limestone calcination
  • High-temperature kiln firing (energy-intensive)
• When used in ground stabilisation, cement emissions typically range from 150–300 kg CO₂ per m³ of stabilised material, depending on the mix and binder ratio

While the stabilisation avoids the need to excavate and import new materials (which saves some emissions), the carbon cost of cement itself usually dominates the calculation. 

Carbon Footprint of Aggregates 

Aggregates, be they natural primary, secondary, or recycled are abundant, and their inherent carbon footprint is very low: 

• Extracting, processing, and transporting aggregates typically emits <5–10 kg CO₂ per tonne
• Even when factoring in ‘trucking’ over moderate distances, the total carbon impact is often an order of magnitude lower than cement-based methods

However, aggregates come with logistics impacts: 

• Excessive extraction can have local environmental consequences (habitat loss, dust, noise)
• Quarrying and hauling materials require fuel and contribute to traffic emissions

Land-Use Legacy: Cement-Stabilised Ground vs. Aggregates 

A critical and often overlooked aspect is the reversibility of land use: 

• Cement-stabilised ground undergoes a chemical and structural transformation. Once stabilised, the soil effectively becomes a composite material (similar to low-grade concrete)
  • This land cannot easily be returned to agricultural use, as the soil profile and permeability are permanently altered
  • Future land-use flexibility is reduced, potentially locking the site into non-agricultural uses
• Aggregate bases, by contrast, can often be removed, and the underlying ground can be restored (sometimes with topsoil replacement)
  • This makes them more compatible with future land-use changes, particularly if agricultural reinstatement is a long-term goal

Balancing Carbon and Land Use

From a carbon perspective, aggregates win hands-down due to the heavy CO₂ load from cement production. 

From a practical and engineering perspective, cement stabilisation may be more efficient if: 

• The site has poor material
• There are significant savings in transportation
• The land is never intended to return to agricultural use

But once long-term land use is considered, especially for projects with future agricultural or ecological aspirations, the permanent change introduced by cement stabilisation is a serious drawback. 

Conclusion

In summary, while cement stabilisation offers strong engineering benefits, its carbon intensity and irreversible land-use change often make it a less sustainable option compared to the use of aggregates. For projects seeking to minimise embodied carbon and preserve future land flexibility, low-carbon aggregates, despite their transportation needs, often come out ahead. 

Our Solution: Ecoblend®

It’s clear that aggregates offer an advantage in carbon performance and land-use reversibility. Ecoblend builds on this by combining recycled or manufactured aggregate (IBAA) with secondary materials to create high performance aggregates. It meets engineering standards while reducing reliance on carbon-intensive cement and natural resources. This positions Ecoblend as a practical solution for projects aiming to minimise environmental impact, without compromising quality. 

Find out more about how it can support your next project meet its sustainability goals on the Ecoblend website.