Adoptable Haul Roads Delivered from Waterlogged Greensand with SMR UK Solutions

A network of continuous haul roads totalling approximately 10,000 m² was required to support site traffic and operations. These haul roads were later adopted into the permanent carriageway design, making performance and long-term durability critical from the outset.

Ground Conditions & Challenges

The site comprised predominantly greensand material, which becomes extremely unstable when saturated. Following periods of heavy rainfall, large areas of the site became heavily waterlogged and unworkable, with the material turning into a slurry-like condition once trafficked.

To achieve the required 5% CBR for machine traction using traditional methods, the contractor would have needed to:

• Excavate up to 1.5 m deep across saturated areas
• Dispose of unsuitable material
• Import large volumes of 6F2 aggregate
• Construct a working platform from imported material

This approach would have significantly increased costs, extended programme timelines and generated substantial environmental impact through material importation and disposal.

The SMR UK Solution

Step 1: Targeted Pre-Treatment with SMR DryBind

In areas where the ground was too saturated to support machinery and at risk of sinkage, SMR DryBind was applied as a pre-treatment only.

SMR DryBind was used selectively where ground is unworkable due to excessive moisture or machine sinkage risk. It was not required across all areas — only where conditions prevent effective processing.

Two 360° excavators mixed SMR DryBind into the saturated ground in situ, turning and aerating the material to promote moisture reduction and improved workability.

• Application rate: approx. 1 bag per 60 m²
• Mixed in situ using excavators
• Left for 24 hours to dry and improve handling
• Achieved required 5% CBR for machine traction

This created a workable platform without excavation, enabling safe plant access and preparation for full stabilisation.

Step 2: Full In-Situ Stabilisation with SMR ReBind

Once workable, the site-won material was stabilised using SMR ReBind, one of SMR UK’s hydraulic binders, to convert the existing ground into an engineered structural layer, in line with CD 225.

• All works were completed in situ:
• Treatment depth: 300 mm
• Addition rate: 4% SMR ReBind
• Processed using SMR UK’s One-Pass Mixing Method
• Completed with no machine sinkages due to SMR DryBind Pre-treatment

The stabilised layer formed a robust haul road and structural foundation for ongoing construction activities.

Performance Results

Using SMR DryBind as a targeted pre-treatment, the team successfully achieved the required 5% CBR across heavily waterlogged greensand — a material widely recognised within the construction industry as difficult to stabilise and work with when saturate

Once workability was restored, SMR ReBind was applied to transform the existing material into a high-performance structural layer, achieving minimum CBR values of 40–50% and peak results of up to 80%. This enabled the treated layer to function not only as a durable haul road for trafficking but also as a permanent base incorporated into the final infrastructure design.

Engineering & Commercial Benefits

This solution eliminated the need for traditional dig-out methods, removing the requirement for 1–1.5 m deep excavation to achieve a workable subgrade for mobilisation and avoiding the additional cost of rebuilding that layer for permanent roads.

By stabilising the existing ground in situ, the project avoided importing large volumes of 6F2 aggregate, significantly reducing muck-away, disposal costs and reliance on external materials. Saturated greensand was successfully converted into a structural layer, maximising reuse of site-won material while reducing lorry movements, carbon emissions and overall programme duration.

Conclusion

The stabilised haul roads were ultimately incorporated into the permanent carriageway design as sub-base, eliminating the need to remove temporary works and creating lasting value for the project.

Through the combined use of SMR DryBind and SMR ReBind, ground once considered unsuitable for construction was transformed into a durable, engineered asset, demonstrating a more sustainable, cost-effective and technically robust approach to site development.