Analytical determination of thermal expansion of rocks and concrete aggregates

Monitoring and testing of buildings and structures

The article provides selection and approbation of the model and the model-based method for the analytical determination of thermal expansion and rock fracturing (decompression) and concrete mineral aggregates according to the data about thermal deformations of minerals based on information of the mineral composition, the average grain fineness of minerals and the elasticity modulus of rock. To accomplish the research, the author has used two models available in scientific publications: 1. Balashov and Zaraisky Model for calculating the thermal expansion and decompression of rock based on thermal deformations of minerals. The model does not take into account the structure and mechanical properties of rock. 2. The model of Denisov (one of the authors of this work) and Dubrovskiy was developed and evaluated earlier for the analytical determination of radiation expansion and rock fracturing when neutrons are irradiated by nuclear reactors on the basis of radiation deformation of minerals. The model takes into account the grain fineness and elasticity modulus of rock. The model is accepted for research on the basis of the analogy between the processes of thermal and radiation changes of rock at the level of interaction in mineral crystals. The approbation was done on the basis of both the information available in the scientific publications and experimental data obtained in this work which have shown thermal expansion of 22 in magmatic and sedimentary rock in the range from 20 to 700 °C. It has been determined that the model of Denisov and Dubrovskiy especially with correction introduction associated with the increase in the rock plasticity when heated is adequate and better than the Balashov and Zaraisky Model which describes the process of thermal expansion and rock fracturing. This model can be used for the analytical determination of thermal expansion and isotropic rock fracturing and concrete mineral aggregates at temperatures up to 700 °C (the most reliable – up to 500 °C) at normal pressure and humidity with the absence of included minerals that provide water and gases emission when heated.