finstabilisering

Finstabilisering is a geotechnical technique used to improve the engineering properties of fine‑grained soils, such as clays and silts. The aim is to increase strength and stiffness, reduce compressibility and swell, and enhance durability of fills, subgrades, and other earthworks where fine materials dominate. Stabilization typically involves adding binders to the soil through mechanical mixing, either in the field or at a mixing plant. Common binders are lime, cement, or mixtures of lime and cement, with dosages expressed as a percentage of the dry soil mass.

The stabilizing mechanism combines physical and chemical effects. Mechanical mixing disperses the binder uniformly, while chemical reactions—such as flocculation of clay particles and pozzolanic or cementitious bonding—create cementitious products that bind soil grains. This leads to changes in particle arrangement, reduced plasticity, improved particle interlock, and enhanced drainage and strength. The result is a soil matrix with greater bearing capacity and lower susceptibility to shrink‑swell and long‑term settlement.

Applications of finstabilisering include road and highway subbases, airport runways, foundations, backfills for retaining structures, and embankments where high plasticity or moisture sensitivity would otherwise cause performance problems. Advantages typically include higher strength, better stability under moisture changes, and improved workability of the material during construction. Limitations involve cost considerations, environmental impact from binder production, potential variability due to soil properties, and the need for proper design, testing, and curing conditions.

Design and evaluation rely on geotechnical tests such as Atterberg limits, standard Proctor compaction, shear strength tests, and, when relevant, CBR measurements, to determine appropriate binder type and dosage. See also soil stabilization; lime stabilization; cement stabilization.