Tukikerrokset

Tukikerrokset are layers in pavement structures that lie between the subgrade and the surface course. Their primary purpose is to distribute traffic loads over a larger area, increase the pavement’s structural capacity, and control moisture and frost effects. By providing a stable intermediary, tukikerrokset help reduce settlement and improve long-term performance of the pavement.

Common materials for tukikerrokset include granular aggregates such as crushed stone, gravel, and sand. These can be used as unbound layers or stabilized with binders like cement, lime, or asphalt emulsion to increase stiffness. In practice, a tukikerros may function as a base layer or a subbase layer, or as a combination of both, depending on climate, traffic levels, and subgrade characteristics. Drainage layers or geosynthetic reinforcements are sometimes incorporated to improve water removal and stability.

Design considerations for tukikerrokset include expected traffic loads, climate and frost conditions, and the bearing capacity of the subgrade. The thickness and material choice are selected to achieve the desired structural performance and to ensure adequate drainage. Design methods may involve concepts such as structural number or modulus-based approaches, adapted to local standards and practices.

Construction and maintenance focus on proper compaction and moisture control during installation, ensuring continuous drainage paths, and monitoring for settlement or moisture-related damage. Regular inspection of drainage provisions and surface integrity helps preserve the effectiveness of tukikerrokset over time.