Presented research was performed in framework of the ATHOR project, standing for “Advanced THermomechanical multiscale mOdelling of Refractory linings”. This European project involves 15 early stage researchers trained within the network of 7 universities and 8 industrial partners. The present study focuses on alumina spinel refractory used in lining of steel ladle. This high performant material contributes to increase of steel plant’s profitability, and thus attracts interest of industrial entities. The objective is to better understand relationships between material’s microstructure and thermomechanical properties in working conditions, as well as to identify thermomechanical properties to be used in numerical simulations. These two objectives are mainly achieved by acoustic emission, ultrasonic, dilatometry and XRD measurements, as well as by mechanical testing, including uniaxial tensile or Brazilian tests. Hysteresis loop, from the graph of Young’s modulus evolution during thermal treatment, is mainly related to microcracks. Moreover, specimen elongation of about 0.08% observed after one hour of dwell at 1500°C could be linked with interactions between alumina and spinel grains. Both phenomena might have beneficial impact for the lining. Microcracks might improve thermal shock resistance and specimen elongation may promote joints closure.