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• Computational nonlinear homogenization of refractory masonry is performed. • Effects of joints closure/reopening on the mechanical behavior are considered. • Computationally efficient homogenized elastic-viscoplastic model is developed. • Dry joints close and reopen due to cyclic loading and unloading. • The homogenized mechanical response of the masonry is orthotropic and nonlinear. [Display omitted] Refractory masonry with dry joints is widely used in the steel-making industry for the linings of several high-temperature components (>1500 ∘ C) including steel ladles and furnaces. To properly optimize the design and performance of these linings, thorough numerical models that consider the presence of joints, joints closure and reopening and the nonlinear elastic-viscoplastic behaviour (creep and stress relaxation) of refractories at high temperature are required. The present study reports on the formulation, numerical implementation, and application of a homogenized multi-scale elastic-viscoplastic model for the simulation of refractory masonry linings with dry joints. Refractory bricks are considered to exhibit linear elasticity as well as rate-dependent plasticity. Four joint patterns are predefined based on the state of bed and head joints. The homogenized elastic-viscoplastic behaviour of each joint pattern is determined using finite element based nonlinear homogenization approach. The transition criteria between the four patterns are defined in terms of macroscopic stresses and strains. Verification of the developed homogenized constitutive laws is carried out by comparing the numerical results of the detailed micro models (brick and joints are considered) with the homogeneous equivalent material models. Furthermore, comparisons with experimental results of refractory masonry walls subjected to biaxial compression load at room and high temperature are carried out. Good agreements between the experimental and numerical results are obtained. Then, the validated models are employed to predict the mechanical behavior of refractory masonry structures subjected to different loading conditions. The present numerical model is able to simulate the orthotropic, compressible, rate-dependent homogenized behaviour of mortarless refractory masonry structures, and accounts for joints closure and reopening due to loading and unloading. [ABSTRACT FROM AUTHOR]

• A comparison is performed between two modelling approaches, the homogenisation approach (macro-modelling) and the micro-modelling approach. • Both modelling approaches provide a reliable prediction of masonry response at the ambient and high temperatures. • These modelling approaches can be used in combination. Refractory masonry with dry joints is widely employed as a protective lining in industrial applications requiring high-temperature treatments. The thermal and mechanical behaviour of alumina spinel refractory masonry is investigated for a wide range of mechanical loading conditions at ambient and high temperature up to 1500 °C within the framework of the ATHOR project. This paper discusses the different numerical analysis approaches for the simulation of the experimental results. Micro and macro modelling approaches show good agreement with the large scale uniaxial and biaxial compression tests for loading and unloading at the ambient temperature. Simulations carried out for large scale uniaxial and biaxial creep tests as well as biaxial relaxation tests at 1500 °C show good agreement. The numerical results indicate the ability of these modelling approaches to represent the complex thermomechanical behaviour of the refractory masonry. Both methods demonstrate an orthotropic and highly nonlinear behaviour of the refractory masonry as observed in the experimental campaign. The numerical outcome, validated with experimental results demonstrate compatibility between micro and macro modelling approach that can be employed to evaluate local and global behaviour of large industrial installations. [ABSTRACT FROM AUTHOR]

• 13 large-scale tests have been performed at room and high temperature (1500 °C). • Masonry showed orthotropic behaviour due to the gradual closure of joints. • After joints' closure, the observed behaviour was isotropic. Refractory linings can withstand severe working conditions and are widely used for the linings of many high temperature applications, such as steel ladles. Some of these linings are built with dry joints. These structures undergo very complex responses in service conditions, making the prediction of its behaviour a challenging task. To develop robust numerical prediction tools, experimental validation is necessary. The present paper gathers a considerable database on the mechanical and thermomechanical characterization of refractory masonry with dry joints (up to 1500 °C). The test setups, measurement techniques, specimens, test procedures, and results of the large-scale experimental campaign are presented. The results of the tests help in understanding the complex thermomechanical behaviour of refractory linings. Aspect such as joints closure and reopening, dimensional and shape tolerances of the bricks, creep and stress relaxation are investigated. The results of these tests are essential for developing, calibrating, and validating efficient numerical models for the design and optimization of refractory masonry linings. [ABSTRACT FROM AUTHOR]