Приведены результаты использования комплексной методики анализа поведения цементных составов, содержащих силикатные добавки, в условиях высокотемпературного нагрева. В ходе эксперимента расширены условия испытаний, принятые в стандартных методиках по оценке высокотемпературных воздействий на цементные составы. К общепринятым методикам добавлены исследования термохимических свойств на уровне структурообразования исследуемых образцов. Проведена корреляция результатов, полученных разными методами. Показано, что при динамичном высокотемпературном нагреве цементного камня происходит его разложение на различные химические составляющие, формируется структура композиционных вяжущих в процессе гидратации, а также улучшается ряд теплофизических свойств цементных составов, содержащих силикатные добавки.
Nowadays new methods, based on the latest achievements of physics, physical chemistry and electronics, for a comprehensive scientific study of the behavior of building materials at elevated temperatures are used. The research of physical, chemical and physico-mechanical transformations, that can change the condition and properties of the material, and assessment of the behavior of building structures at elevated temperature can be provided with the help of X-ray analysis, thermal analysis, testing of building structures for fire resistance, and others. The analysis of examined methods shows, that there are no active methods of complex analysis of the behavior of materials at elevated temperatures in structures. The available methods for determining fire resistance and thermal stability do not give a full assessment of fire danger of building designs and building materials. That is the reason of my research. The aim of this work is to study the influence of different components of the mixture to the behavior cement composites containing silicate additives at elevated temperatures using a complex methodology of analyzing the behavior of cementitious compositions in the dynamics of heating and correlation of test results. Research were conducted on heat-resistant cementitious compositions by three different methods. The behavior of cement composites, containing silicate additives, at elevated temperatures was analyzed using the complementarily of certain characteristics, and the settings which allow for testing of construction materials on the flammability, differential thermal analysis (DTA), as well as the measurement of thermal conductivity and the coefficient of thermal resistance. At the end of the research based on complex methods, it was determined that in the process of heating of the cement stone it is decomposed into different chemical components, and the structure is formed of composite binder during the hydration process, improved a thermal properties of cement compositions containing silicate additives. However, in the case of usage any one method to determining the thermal and thermo-chemical properties the results were not always objective. Application of a complex method of analyzing the behavior of cement compositions at elevated temperatures gives the possibility of assessing the fire hazard of building materials based on cement composites. In addition of application of theoretical methods of calculating the fire resistance of building structures complex method allows to predict the behavior of building structures based on various cement composites under fires of varying difficulty.
The authors declare that there are no conflicts of interest present.