Roads and civil engineering

Quicklime rapidly dries wet soils and flocculates clay particles, improving workability and increasing load-bearing capacity. Over time, it reacts with clay minerals through pozzolanic reactions, forming cementitious compounds that progressively strengthen and stabilize the soil. These improvements reduce both the financial and environmental costs of earthworks by accelerating construction and increasing overall project efficiency.

Lime for soil treatment in earthworks

Lime treatment transforms difficult soils into stable and workable construction materials. It reduces plasticity, improves compaction, and increases mechanical performance - creating durable layers for roads, railways, dikes, and industrial platforms. By enabling the reuse of local soils, lime treatment reduces material transport, lowering both project costs and environmental impact.

Workability

Quicklime hydrates rapidly in the presence of water, generating heat that accelerates the drying of wet soils. At the same time, calcium ions from the lime neutralize clay particle charges, promoting flocculation and reducing plasticity. The result is a soil that is easier to handle and compact, delivering improved load-bearing capacity for safer site access and a stable, reliable subgrade.

Stabilization

Lime treatment provides long-term stabilization through pozzolanic reactions. As lime reacts with clay minerals, it forms strong cementitious compounds that significantly increase soil strength and cohesion while limiting swelling and shrinkage. These long‑term improvements enhance resistance to water, frost, and erosion, maintaining structural integrity over decades of operation. Field monitoring of embankments shows that lime‑treated soils maintain high mechanical performance under real conditions - providing a durable and cost‑effective solution for infrastructure projects.

Erosion resistance

Lime treatment strengthens soil structure through pozzolanic reactions, forming a stable, cohesive matrix with high erosion resistance. Its effectiveness has been demonstrated on flood-protection dikes, where lime treatment reduced soil loss under hydraulic stress and, preserved structural integrity even during extreme weather events.

On road embankments, lime treatment can limit flood-related damage, reduce maintenance requirements and lower the risk of structural failure - improving long-term resilience.

Lhoist lime solutions help you:

• Reduce natural aggregate consumption by reusing excavated soils
• Minimize worksite traffic by up to 95%, reducing the impact on local communities
• Accelerate construction schedules while lowering costs
• Improve infrastructure durability and resilience to extreme weather

Our low-dust quicklime supports safer application in urban environments. For dry climates and highly clayey soils, we also offer liquid-form products designed for a faster and more efficient application.

Earthwork backfill operations

Earthworks and trenching generate large volumes of excavated soils that are often landfilled. Lime treatment upgrades these soils so they can be reused safely and efficiently – for trench backfill, site leveling, or reinforcement of weak subgrade layers. This reduces waste, limits heavy-truck traffic, and lowers overall project costs.

Lhoist premium quicklime improves the erosion resistance of soils used in hydraulic structures - such as dikes, levees, and riverbanks. It preserves the natural permeability while increasing mechanical stability and ensuring long-term performance in water management applications.

Lhoist products improve aggregate quality through dry, water‑free treatment. Aggregates contaminated with sticky clays can create major processing issues in crushers and screeners - particularly in wet conditions - and are often discarded. Lime treatment facilitates clay separation and removal, improving processing efficiency, and improving their suitability for concrete and asphalt applications.

Lime treatment stabilizes and conditions dredged sediments, making them safer and easier to reuse or dispose of. Lime improves slurry conditioning and dewatering performance, supporting reliable downstream processing.

In tunnel construction, hydrated lime improves the rheology and deformation capacity of backfill mortars and grouts, reducing the need for costly organic additives and consequently lowering formulation costs. Quicklime dries and flocculates drilling muds, improving their manageability during excavation and underground operations.

Lhoist develops durable and cost-efficient solutions for hot-mix and cold-mix asphalt. These tailor-made filler blends can be integrated without modifications to dosing equipment and reduce sensitivity to:

• Moisture and stripping damage,
• Freeze-thaw cycles,
• De-icing salts,
• Rutting and age-hardening

Studies by infrastructure owners indicate that hydrated lime can extend pavement service life by 25% or more. 

Milk of lime can also be used to protect tack coats by preventing contamination and reducing bitumen pickup on truck tires. It can also help prevent asphalt bleeding in hot weather conditions.

Milled limestone plays a key role in modern concrete design, as it improves particle packing, reduces porosity, and strengthens long-term durability. It also helps lower the heat of hydration, which is critical for mass concrete where thermal control is required. By partially replacing clinker in cement, limestone helps reduce CO₂ emissions and supports more sustainable construction. The result is improved workability and lower environmental impact.

Lhoist aggregates and stones provide reliable solutions for landscaping and hydraulic engineering projects. Larger stone grades are used to protect riverbanks, control erosion, and stabilize edges in demanding environments.

Our civil engineering solutions - Asphacal^® and Proviacal^® - support your road and infrastructure projects with reliable performance and proven quality.