CONCRETE STRENGTH in DIFFERENT ENVIRONMENTAL CONDITIONS DEPENDING ON ELECTRICAL HEATING PARAMETERS

Abstract

Concreting of thin-walled structures and elements of medium massiveness is performed using the electrical heating method. Approximate calculations according to existing methods do not take into account many factors in concrete curing during winter concreting. All approximations and simplifications do not provide the proper temperature concrete curing in winter, clear distribution of temperature fields, the nature of structural temperature changes with time. Modeling with the use of modern software and computer systems can solve this problem. The paper proposes a method of parametric analysis of the concrete strength generation using a heating cable. The method includes computational models of thermal conductivity for three types of formwork and using the ELCUT software package for calculating non-stationary temperature fields at various ambient temperature, wind speeds and space for laying heating cable. The analysis the temperature fields in concrete with regard to the exposure time, makes it possible to estimate its strength development. It is shown that in formwork 6 the temperature field is the most uniform, while in formwork 2 it is the least uniform. Formworks 4 and 6 with 300 mm space for cable laying provide the most effective electrical heating of thin-wall structures.