Numerical analysis of the ground temperature function depending on edge thermal insulation parameters for shallow slab foundations

The paper presents an analysis of sixty-four variants of joints between walls and foundation slabs with edge thermal insulation for shallow foundation by varying the length, thickness, and inclination angle of edge thermal insulation. The analysis was undertaken to verify the effect of thermal insulation installation angle, thermal insulation thickness and thermal insulation length on temperature in the ground at the edge of the foundation. A key task of edge thermal insulation of foundation slabs is to maintain a positive temperature at the level of the building's foundation which is especially important for countries located in cold climates. Considered solutions are most often based on the proposals of the PN-EN ISO 13793 standard, which, however, does not take into account all possibilities of thermal insulation, in particular locating it at an angle therefore, verification of this element was undertaken. The simulation results indicated the greatest effectiveness in the case of use the thermal insulation at an angle of approximately 45°, on the basis of which it was recommended to use such a solution. It was also confirmed that the length of thermal insulation has a greater impact than its thickness on the temperature distribution in the ground. The paper provides recommendations for protecting the foundation area against frost heave. It also suggests further research directions which may be the basis for develop a catalogue of design and implementation solutions for shallow slab foundations.