Thermomechanical modelling of a blast furnace hearth

The goal of this work is to develop a thermo-mechanical model of a blast furnace hearth able to estimate the stress state in service. To identify the behaviour of bricks, mortars and ramming mix, characterization tests have been developed for temperatures up to 1500°C. A modified Cam-clay model is identified for the ramming mix. The masonry modelling is based on a macroscopic approach where bricks and mortars are replaced by a set of equivalent homogeneous materials accounting for the different joint states (open or closed). The non linearity of the behaviour is reproduced thanks to a stress criterion, allowing the transition from one state to another. The final modelling of a hearth is compared with in-situ instrumentation results.