päällystyskerroksen

Päällystyskerros, often translated as pavement or surfacing, refers to the uppermost layer of a road or pathway designed to withstand traffic loads and provide a smooth driving surface. It is a critical component of the overall road construction, built upon a foundation and base course. The primary function of the päällystyskerros is to distribute the stresses from vehicles to the underlying layers and protect them from water infiltration and weathering.

Common materials used for päällystyskerros include asphalt concrete and Portland cement concrete. Asphalt concrete, a mixture of bitumen binder and aggregates, is widely used due to its flexibility and relatively lower initial cost. It can be applied in various types, such as hot-mix asphalt (HMA) for high-traffic roads and warm-mix asphalt (WMA) for environmental benefits. Portland cement concrete, made from cement, aggregates, and water, offers greater durability and load-bearing capacity, often preferred for heavy-duty pavements like highways and airport runways.

The design and thickness of the päällystyskerros are determined by factors such as expected traffic volume and weight, climate conditions, and the strength of the subgrade. Proper construction techniques, including controlled compaction and temperature, are essential to ensure the longevity and performance of the pavement. Maintenance, such as crack sealing and resurfacing, is also vital to extend the service life of the päällystyskerros and prevent more extensive damage to the road structure.