What Is Lime Modification?
Lime modification involves mixing quicklime or hydrated lime directly into cohesive soils such as clays, silty clays, and boulder clays. The lime reacts instantly with water and clay minerals to:
- Rapidly reduce moisture content
- Significantly lower soil plasticity
- Break down stubborn clay clods
- Vastly improve friability and workability
- Increase short-term strength and bearing capacity
In many Irish projects, lime modification is the essential first step that allows earthworks to proceed on ground that would otherwise be entirely too wet or soft to traffic.
Where Lime Modification Is Used
Lime modification is heavily relied upon across Ireland for projects dealing with glacial till and boulder clays, particularly where high natural moisture contents occur.
Benefits of Lime Modification
Engineering Benefits
Instantly improves workability and compaction. Delivers much higher short-term bearing capacity while completely reducing rutting and deformation under heavy construction traffic.
Cost & Programme
Drastically reduces the need for thick imported stone platforms. Prevents the costly excavation and disposal of soft soils, allowing you to work straight through adverse weather.
Environmental Focus
Keeps trucks off the road with fewer lorry movements to and from site. Reduces the quarrying of new aggregates by maximising the reuse of your existing site-won materials.
Our Lime Modification Process
Site Assessment & Testing
We review ground investigation data and, working with independent laboratories, carry out testing to determine the precise lime types and dosages needed for your specific clay.
Binder Delivery & Storage
Lime is delivered in bulk tankers and stored safely in suitable silos on-site, with all appropriate safety and handling measures strictly enforced.
Controlled Spreading
Using state-of-the-art calibrated spreaders, we apply the lime at the exact required dosage uniformly across the treatment area, preventing waste and ensuring quality.
Mixing & Pulverisation
Our specialist hybrid drums and mix plants churn the lime through the soil to the specified depth, breaking down dense clods to create a uniform, workable material.
Compaction & Curing
The modified soil is immediately compacted using heavy rollers and allowed to chemically react and gain rapid strength over a specified curing period.
Verification & Monitoring
Where required, strict on-site testing is carried out to irrefutably confirm that the modified foundation meets all agreed engineering performance requirements.
Safety and Handling
Lime is a highly reactive material that must be handled with care. SSI ensures strict use of appropriate PPE, safe storage/transfer procedures, advanced dust control measures, and clear safety communication with all other trades operating on your site.
Part of a Wider Solution
On many Irish projects, lime modification is combined with a second phase of Cement Stabilisation. Lime is used first to dry the wet cohesive soil, and cement is subsequently added to achieve the massive long-term strength required for capping or sub-base layers.