DETERMINING THE REQUIRED CONCRETE STRENGTH IN WINTER TIME

Abstract

The article considers the issue of determining the required strength of monolithic structures in
winter, at which they are allowed to be stripped and frozen. The absence of clear requirements for
the assessment of the necessary strength in the existing regulatory documents is shown. The comparison
of the critical and stripping strengths of concrete is carried out, the influence of the work
production time on the choice of the required strength is estimated, and the need to take into account
the influence of the temperature difference between the concrete surface and the outside air in the
determining of the stripping strength of concrete is shown. The data of calculations, indicating the
economic inexpediency of high values of the required strength of concrete and demonstrating an exponential
increase of time spent on heat treatment are presented. In the example, an increase in the
required strength of concrete by 15 % (from 80 to 95 % of the designed one) leads to an increase in
the time spent on heating concrete by 2 times, and with its increase by 20 % (from 80 to 100 % of
the designed one) – the time costs increase by 3 times. Conclusions are made about the need for design
organizations in the Project section of the organization of construction to indicate the specific
values of the required

strength of concrete for different structures, while taking into account the
economic feasibility