Mechanical homogenisation of masonry wall without mortar

Nguyen, TN; Blond, Éric; Gasser, Alain; Prietl, T.

doi:10.1016/j.euromechsol.2008.12.003

Cited by 28 publications

(37 citation statements)

References 16 publications

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“…Behaviour of the dry joints, especially in the refractory masonry, is less investigated. It is known that under compression the stiffness of the refractory lining will decrease with increasing amount of joints [6]. At room temperature the dry joint closure has been measured for alumino-silicate refractory bricks.…”

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confidence: 99%

Compressive behaviour of dry joints in refractory ceramic masonry

Andreev¹,

Sinnema²,

Rekik³

et al. 2012

Construction and Building Materials

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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. IntroductionRefractory ceramic linings of high temperature furnaces are often built with bricks. Brick chemical composition and geometry are selected regarding the service conditions and the lining structure [1]. Due to the conditions of constrained thermal expansion high compressive stresses often develop in the bricks [2]. In many furnaces, including the blast furnace and the converter of the steel industry, bricks are laid on a dry joint, without usage of mortar. Most investigations on the mechanics of masonry consider civil structures with mortared joints [3][4][5]. Behaviour of the dry joints, especially in the refractory masonry, is less investigated. It is known that under compression the stiffness of the refractory lining will decrease with increasing amount of joints [6]. At room temperature the dry joint closure has been measured for alumino-silicate refractory bricks. Optical technique was used for the purpose. The ability of the dry joint to reduce compressive stresses was attributed to imperfect initial contact due to the roughness of the brick faces [7]. The quantitative knowledge of joint effects is an essential design parameter. As an example one can regard the superposition of the stress reducing effect of the joint and of expansion release inserts. The latter are introduced in form of card-board plates in several joints of the masonry wall to allow free expansion when the card-board burns up [2]. If the combined effect of the joints and the inserts is too high the lining is not tight enough. In the cyclic operation combining regular heating and cooling, and in some cases featuring rotational movement, loose lining can lose its stability and collapse. On another hand, too tight lining may fail under high compressive stresses. This paper investigates the compressive closure of dry joints in two classes of refractory bricks -magnesia carbon and magnesia chromite bricks. Regarding the service conditions of the bricks the measurements were performed in wide temperature range. The process of joint closure was measured indirectly by compressing samples with and without joints. At room temperature, also direct optical measurements were performed. FEM computer analysis was used to interpret the measurement results. The general aim of the investigation was to obtain data on the compressive joint closure behaviour to get a better insight into the masonry stress state a...

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confidence: 99%

Compressive behaviour of dry joints in refractory ceramic masonry

Andreev¹,

Sinnema²,

Rekik³

et al. 2012

Construction and Building Materials

Self Cite

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“…However, sometimes, for instance, in blast furnaces, the initial gaps are designed and obtained using cardboard blocks during the installation of masonry to compensate for thermal expansion effects. Indeed, many studies have shown that joints have a great impact on the overall thermomechanical response of mortarless refractory masonry (working lining) [2,3] as they allow the bricks to expand freely (until closure of joints), resulting in lower values of compressive stresses; then, after closure of the joints, compressive stresses increase at a higher rate [4,5].…”

Section: Introductionmentioning

confidence: 99%

Transient Thermo-Mechanical Analysis of Steel Ladle Refractory Linings Using Mechanical Homogenization Approach

et al. 2020

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Mortarless refractory masonry structures are widely used in the steel industry for the linings of many high-temperature industrial applications including steel ladles. The design and optimization of these components require accurate numerical models that consider the presence of joints, as well as joint closure and opening due to cyclic heating and cooling. The present work reports on the formulation, numerical implementation, validation, and application of homogenized numerical models for the simulation of refractory masonry structures with dry joints. The validated constitutive model has been used to simulate a steel ladle and analyze its transient thermomechanical behavior during a typical thermal cycle of a steel ladle. A 3D solution domain and enhanced thermal and mechanical boundary conditions have been used. Parametric studies to investigate the impact of joint thickness on the thermomechanical response of the ladle have been carried out. The results clearly demonstrate that the thermomechanical behavior of mortarless masonry is orthotropic and nonlinear due to the gradual closure and reopening of the joints with the increase and decrease in temperature. In addition, resulting thermal stresses increase with the increase in temperature and decrease with the increase in joint thickness.

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“…For reasons of durability and resistances to harmful factors (fire, water, chemical products, etc. ), the conventional bonded masonry is replaced by mortarless masonry systems such as interlocking mortarless hollow concrete block systems [39], dry-stack mortarless sawn stone constructions (as the Egyptian pyramids and the Zimbabwe ruins for example) [37] and refractory linings of industrial furnaces including vessels of steel industry where the ceramic bricks are laid in direct contact with each other [1,11,26].…”

Section: Introductionmentioning

confidence: 99%

“…The developed contact relations for dry joint within specified bounds can be used for any mortarless masonry system efficiently with less computational effort. As a continuity of the work of Gasser et al [11], Nguyen et al [26] proposed a model based on linear homogenization technique performed with finite element method. It derived four equivalent homogeneous materials for which mechanical properties depend on the joint state, on the basis of the joint opening/closure mechanism.…”

Section: Introductionmentioning

confidence: 99%

Experiments and nonlinear homogenization sustaining mean-field theories for refractory mortarless masonry: The classical secant procedure and its improved variants

Rekik¹,

Allaoui²,

Gasser³

et al. 2015

European Journal of Mechanics - A/Solids

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In order to support the optimization of mortarless brick linings of steel producing furnaces it is proposed in this paper to investigate only the compressibility of dry refractory joints. To this end, optical measurements based on the Digital Image Correlation method were carried out during compression of Magnesia-Carbon brick samples with dry joints. The second main objective is to assess the accuracy of the secant linearization schemes (the classical secant procedure and its modified extension) to reproduce the reference local and global behaviour of refractory mortarless linings accounting for the identified inelastic convex power-law behaviour of the Magnesia-Carbon dry joint. The reference nonlinear solution is obtained by means of finite elements method. Under normal compressive loading, unlike for usual (concave) power-law viscoplastic composites for which the secant schemes are known to provide too stiff results, it was found that the modified secant scheme leads to good overall predictions. The classical secant procedure underestimates the reference local and overall behaviour. To improve the latter result, an empirical improved secant formulation was proposed and implemented. It leads to better estimates at local and global levels.

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Mechanical homogenisation of masonry wall without mortar

Cited by 28 publications

References 16 publications

Compressive behaviour of dry joints in refractory ceramic masonry

Compressive behaviour of dry joints in refractory ceramic masonry

Transient Thermo-Mechanical Analysis of Steel Ladle Refractory Linings Using Mechanical Homogenization Approach

Experiments and nonlinear homogenization sustaining mean-field theories for refractory mortarless masonry: The classical secant procedure and its improved variants

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