Thermomechanical behavior of refractories

The quantification of thermomechanical stresses therefore plays a central role. This is done through the tool of modeling by finite elements. Modehng has developed considerably, due to the arrival of powerfid computers on the market accessible to laboratories and to the wide distribution of suitable software. 

Observation, a seeond tool, more traditional in nature, retains its importance. It is in fact observation assoeiated with measurements, if neeessaty, which helps to identify thermomeehanieal degradations and to guide further aetiom 

Thermomechanical degradation of refractories can be largely elassified into three 

Fracture results from the propagation of an in-depth fissure in a part of the lining or in a brick. In practice, insofar as the shaped pieces dissociate from each other, fracture translates in the loss of material, of thickness ranging from several to around 10 cm. It therefore refers to a catastrophic phenomenon. 

Thermomechanical stresses imposed by service conditions are of two types  

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British Ceramic Research Assoc., Thermomechanical Behavior of Refractory Castable Linings, Technical Note No. 320, March 1981. 

Buyukozturk, O., "Thermomechanical Behavior of Refractory Concrete Linings, Journal of the American Ceramic Society, Volume 65, No. 6, June 1982. 

Schacht CA. The effect of mortar joints on the thermomechanical behavior of refractory brick lining systems in cylindrical vessels. AISE Spring Conference, Birmingham, AL, March 1985. 

The behavioral laws express the relationship between the stress a and deformation e, as well as the evolutions of e as a function of time. These behavioral laws strongly depend on the microstmctnre of the material and its manufactnring process. The thermomechanical behavior of refractories is characterized by two major effects ... 

However, it is the combination of design data such as compressive and flexural stress-strain with thermal measurements that allows us to take that extra step from a material test piece to a working refractory lining or component. It allows us to study the thermomechanical behavior of materials. 

Refractories are part of an extended family of ceramics. A certain number of key words characterizing in some way their complexity can be associated with these materials. These key words ate heterogeneity, diversity of aggregate/binder/additive assemblies, capillary network, corrosion through imbalanced physicochemical processes, non-hnearity of the thermomechanical behavior and scale effect. 

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