Study of thermophysical characteristics of variatropic concretes

Abstract

An important task in the development of the construction industry is to find rational technologies, materials and solutions that ensure energy efficiency in construction and create conditions for obtaining energy-saving products and structures for various construction projects. At the same time, the issue of structures made of the same material, but having a difference in their properties and characteristics in thickness, the so-called variatropic building material, which, due to differences in structure and properties, ensures variatropic properties of the building structure itself, has been poorly studied. The goal of this study was to eliminate a significant scientific deficit, consisting in the absence of a systematized knowledge base on the structure and thermophysical properties of variatropic products and structures made of concrete or reinforced concrete. The modeling was performed in the ANSYS environment (Ansys version 2024 R1). An element selected for modeling was a ring-section heavy concrete pillar with an outer diameter of 450 mm and an inner diameter of 150 mm. Variatropy was specified by conventionally dividing the element’s cross-section into several layers with different physical and mechanical properties: three for centrifuged concrete and four for vibrocentrifuged concrete. In the course of modeling, the authors determined the main initial data for the calculations, and based on the results of the calculations, dependencies were established confirming the improvement of the concrete’s heat-insulating properties due to the use of centrifugal compaction technology. The phenomenon of variatropy leads to an increase in heat-transfer resistance – from 13% for centrifuged concrete to 23% for vibrocentrifuged concrete in comparison with vibrated concrete. At the same time, vibrocentrifuged concrete turned out to be 8% more efficient than centrifuged concrete in terms of “heat-transfer resistance”. The conducted modeling shows that variatropic concrete is promising for further research and practical application in terms of its thermophysical characteristics.