1. Use of average thermophysical characteristics of concrete, regardless of the quality of the cement and aggregate, can lead to errors of 10–15%. Therefore it is desirable to collect research data for quarried aggregates of various mineralogical and petrographical compositions. Investigations on another three or four types will, apparently, give sufficient data on the effect of the composition of the components of concrete on its thermophysical characteristics. 2. The thermal conductivity and thermal diffusivity of concrete are continuous functions of temperature. They increase as the temperature of the concrete falls. 3. The influence of age of the concrete is apparently significant over the first two or three months after placing. Subsequently, the thermophysical characteristics can be assumed to be constant. The values of λ and α decrease by 15–20% as the concrete ages.