PL
The article is a description of the laboratory testing of transient heat flow in small-size samples of concrete and analysis of the impact of spacers made of a polyurethane material to the flow and the temperature distributions in the sample. This problem affects the working of concrete structural members exposed to a wide range of temperatures, and the thermal stresses generated in them, especially when the heat flow is analysed by a combination made of a flexible connection. The results can be used in issues related to the durability of concrete elements and their connections.