Refractory concretes uniaxial compression behaviour under high temperature testing conditions

Two refractory concretes with the same matrix composition, one based on andalusite aggregate and the other on bauxite aggregate, have been studied at temperatures ranging from room temperature to 1200 °C maximal temperature. Samples dried at 110 °C during 24 h to create dried standard specimens and others, fired at different temperatures, were subjected to several uniaxial compression test conditions conducted at various temperatures. The evolution of the materials’ global behaviour from quasi-brittle to viscous was evidenced and correlated to their microstructure evolution. Loading/unloading, creep, and strain rate jump tests helped define the damageable and viscoplastic nature of the behaviour. The influence of the firing temperature and duration on the materials’ behaviour is also reported and discussed. In conclusion, potential constitutive equations that are able to fit the material recorded behaviour are suggested.