New design model for frost protection of a slab on grade

In Sweden the insulation thickness below a typical concrete slab on grade is now between 200 to 300 mm. The reason for using thick insulation is to reduce the heat loss to the ground below the slab and for moisture control in order to create a temperature difference between the slab and the ground. However, this may lead to another problem, the risk for frost heave. In this paper a new model for frost protection is introduced. The intention is to find a design method for frost heave that ensures that the frost front never penetrates below the slab. The damage that frost heave can cause will not be discussed in the paper. The model is based on the assumption that the heat loss from the foundation to the soil beneath the slab is zero. By using a scaling technique it is possible to use only one curve for design against frost heave