ABSTRACT
Cold winter climate and frost must be taken into serious consideration in the construction in Finland The frost heaving has to be controlled with a proper frost protection, which is designed according to the actual design codes using thick pavement layers, up to more than two meters The assessment of frost-heaving risk is based on a frost susceptibility concept, which is classified according to the frost susceptibility of the subsoil and the ground water conditions In the new approach, the frost heaving is estimated using the segregation potential as the heaving characteristic of the subgrade It can be determined from frost heave observations of an old pavement, or estimated using a laboratory frost-heave test or roughly from soil characteristics The frost protection is then determined using the local freezing index, design frost heave The frost protection can be planned using, either, thick mineral layers, or frost insulation Test design and construction has been successfully carried out for more than 10 years at various locations The design subgrade modulus corresponds to the spring modulus, that is estimated using subgrade classification, and the class values correspond to the lowest probable The needed pavement stiffness is determined with elastic analysis to correspond to the traffic loading anticipated for the design period of the road, say, 30–50 years
