Multi-scale study of the mechanical and fire behavior of masonry walls joined with thin adhesive mortar ; Étude multi-échelle du comportement mécanique et au feu des murs en maçonnerie montés aux joints minces

The work presented in this thesis deals with the mechanical and fire behavior offired clay masonry walls joined with thinadhesive mortar. The objective of this work is tocharacterize the behavior at room temperatureand at high temperatures of the wallcomponents (fired clay and mortar) as well as ofthe assemblies with increasing complexity todetermine the effect of scale on the globalbehavior. The goal is also to propose thebehavior laws of these components and toimplement them in a finite element code toanalyze the behavior of walls exposed to fire.The first part concerned the characterization ofthe wall components (brick and mortar) atdifferent temperatures at the material scale.This characterization was then taken intoaccount in the development of the behaviormodels. In the second part, experimentalinvestigations on multi-scale assemblies wereperformed in order to evaluate the distributionof strains, stresses and damages taking intoaccount the structural effects and the impact ofstress concentration. In the last part, based onthe experimental results, a three-dimensionalmodeling was proposed to simulate the firebehavior of the masonry wall by consideringthe behavior laws developed for the brick andthe joint. Validation calculations and parametricstudies were also carried out to highlight theinfluences of mechanical and geometricalparameters on the thermomechanical behaviorof the walls. ; Le travail présenté dans cette thèse concerne la problématique du comportement mécanique et au feu de murs en maçonnerie de terre cuite réalisés avec des joints minces en mortier colle. L'objectif de ce travail est, d'une part, de caractériser le comportement à température ambiante et à hautes températures des constituants (terre cuite et mortier du joint) ainsi que des assemblages à complexité croissante pour tracer l'effet d'échelle sur le comportement d'ensemble. Et d'autre part, de proposer et identifier des lois de comportement de ces composants pour les exploiter dans un code aux éléments finis afin d'analyser le ...