ABSTRACT
The thermos method is one of the most cost-effective techniques used to cure concrete structures cast in place in winter. The temperature of concrete to be placed in a massive structure should be as high as possible. Frozen concrete or rock is best heated to an above zero temperature to a depth of 300 mm. The design of a cast-in-place foundation must take into account the thermal interaction of hardening concrete with permafrost. Concretes for structures to be erected on permafrost should be mixed with Portland cements. The thermos curing of placed concrete produces a nonuniform temperature field over the cross section. The core of the structure expands as it grows warm and so tensile stresses arise in the surface layers of the concrete. The protruding reinforcement greatly affects the variation of the concrete temperature at the interface with the bars and the temperature field in concrete in the vicinity of the protrusions in general.
