Characterization of shear failure of refractory fireclay mortar joints using slant shear test at room temperature

Abstract Mortar joints are commonly used in industrial vessels to stabilize refractory linings. Quantification of their mechanical and thermomechanical behaviors is required for appropriate applications. In this study, slant shear tests of mortar joints using refractory–mortar–refractory sandwich structures were performed at room temperature, and the finite element method was used to explain the mechanisms that cause different types of cracking phenomena within the mortar joint. The impact of the testing configuration and surface roughness of the brick samples on load‐displacement curves and maximum loads was investigated. Maximum loads with small deviations were obtained using an improved preparation method and testing configuration. The cohesion and friction angle, which define the Mohr–Coulomb criterion at room temperature, are calculated and applied in the simulation. It was discovered that the competition between the brick‐mortar interface bonding strength and the mortar strength determined the cracking path, and their impact on the maximum load was slight.