Compressive behaviour of dry joints in refractory ceramic masonry

To support optimisation of refractory masonry structures compressibility of dry joints of magnesia–carbon and magnesia–chromite bricks have been investigated. Laboratory scale tests and finite element modelling have been performed. Measurements done in wide temperature range have shown that the exponential form of the joint closure curve results from gradual closure of initially non-parallel surfaces. The stress needed to close the joint was found to be proportional to the material stiffness. Temperature influences the joint closure by changing the stiffness of material and by reducing the initial joint gap due to thermal expansion.