CONCRETE

[:ru]Янтурина Р.[:en]Yanturina, R.[:] [:ru]аспирант, НИУ ЮУрГУ[:en]PhD student, State educational institution South Ural State University (SUSU)[:]

[:ru]Богусевич Д.[:en]Bogusevich, D.[:] [:ru]инженер-исследователь, ООО УралНИИстром, Челябинск, Россия[:en]research engineer, UralNIIstrom LLC, Chelyabinsk, Russia[:]

Alitinform №6 (45) 2016 г. 36-41 p.

Abstract

There are conditions of operation, when heat-resistant concrete is subjected to cyclic heating and freezing.
Today one of the main problems in the field of heat-resistant concrete is the lack of methodology to evaluate the durability of structures made of such types of concrete in terms of working in open air under cyclic freezing-heating.
The purpose of this paper is to search for methods of testing heat-resistant concrete for heat-frost resistance, which is the most precise characterization to determine durability of the structure, operating under conditions of sharp temperature fluctuations from –50 °C to + 1,200 °C.
The paper discusses basic aspects of testing heat-resistant concrete for thermal resistance according to GOST 20910–90 “Heat-resistant concretes. Technical conditions”. The evaluation of the compliance of the requirements of the national Russian standard to those of the European standard DIN 51068:2008-11 has been performed as well. A method of testing heat-resistant concrete for heat-frost resistance can also be found in this article. Comparative results of tests of heat-resistant concrete for frost resistance, heat resistance and heat-frost resistance are evidenced herein.
Based on the results of field observations, we found that the resistance of heat-resistant concrete, operated in open air and exposed to high only or low only temperatures exceeded the real lifetime of structures made of such concretes by a factor of three at least, and currently existing methods of determining concrete heat resistance and frost resistance do not allow to evaluate the durability of concrete subjected to cyclic freezing and heating.
Thus, the necessity of introduction of methods of testing heat-resistant concrete for heat-frost resistance has been proved.

Key words:

refractory concrete, frost resistance, heat resistance, heat-frost resistance, durability