In this work the connection behavior between precast elements using cement mortar with polypropylene fibers addition is studied to evaluate its performance when compression loads is applied. A numerical analysis with the finite elements program ANSYS 7.1® was made considering mortars range from 0% to 50% of polypropylene fibers addition. The numerical model considered in the analysis was composed of two reinforced concrete blocks with 10x10x20cm dimensions, joined between themselves by a cement mortar with marble and granite residue addition, developed in laboratory, which will receive polypropylene fibers addition. The numerical analysis was later validated by an experimental program. With the gotten results, it was evidenced that lower than 3% tax fibers propitiated better performance of the joint and, consequently, of the model. A profit in the horizontal and vertical deformation capacity was observed prorroguing the mortar splitting in the model, which makes high system strength capacity, resulting in an increase of the connection ductility. Between 4% and 10% the model kept any behavior alteration and from 15%, it started to lose strength and rigidity. The experimental models had presented load capacity profit with fibers addition and similar cracked ways of numerical model and the models observed in literature. However 2% fibers taxes higher were not possible to investigate because a lower workability performance had been gotten. / Fundação de Amparo a Pesquisa do Estado de Alagoas / Neste trabalho estuda-se o comportamento da ligação entre elementos pré-moldados através de juntas de argamassa com adição de fibras de polipropileno, avaliando o desempenho das mesmas quando solicitadas a tensões de compressão. O modelo proposto para análise do comportamento da ligação é composto de dois blocos de concreto armado com dimensões 10x10x20cm, unidos entre si por uma argamassa de cimento e areia com adição de resíduo oriundo do beneficiamento de mármore e granito, desenvolvida em laboratório em uma dissertação de mestrado, a qual recebeu adição de fibras de polipropileno. Faz-se uma avaliação numérica do modelo proposto através do programa de elementos finitos ANSYS 7.1® considerando argamassas com adição até 50% de fibras de polipropileno que é posteriormente validado em um programa experimental. Pelos dados obtidos numericamente, constata-se que o incremento de fibras até a taxa de 3% propicia um melhor desempenho da junta e, consequentemente, do modelo. Observa-se um ganho na capacidade de deformação horizontal e vertical da mesma, prorrogando, com isso, o descolamento do modelo, fazendo com que o sistema mantenha por mais tempo sua capacidade resistente, o que significa um aumento da ductilidade da ligação. Entre 4% e 10% o modelo mantém-se sem alteração no seu comportamento e a partir de 15%, começa a perder resistência e rigidez. Os modelos experimentais apresentam ganho de capacidade de carga com o acréscimo de fibras e modos de fissuração semelhantes ao modelo numérico e aos modelos propostos na literatura. Entretanto os teores práticos de fibras só atingem 2%, o que impossibilita os estudos para os demais teores.

This research work proposes methods to rises the resistance and to evaluate the behavior of confined masonry walls built from clay solid bricks. These elements are widely used in Guerrero State (México) to build masonry structures, which should resist high lateral loads because of the serious seismic hazard. Therefore, a large experimental program to evaluate the mechanical properties of bricks and masonry currently required in the design process and masonry analysis was developed. To rises the masonry resistance and to counteract the influence of the compressive strength of the pieces on the masonry behavior, a high compressive strength mortar and a metallic reinforcement inside the joints were used. With respect to referenced values of the mechanical properties, some were similar and others were twice bigger. In this country zone, the first three tests under lateral load on full-scale confined masonry walls built from clay solid bricks were carried out in order to evaluate its behavior. A reinforcement composed by metallic hexagonal mesh-mortar coat was placed on the faces of two walls to rise or to restore the resistance. The walls showed good behavior and the reinforcement had adequate structural efficiency. Numerical models of panels and walls built by using the experimental data evaluated the envelope resistance, the failure mode and showed the influence of the mechanical properties of the pieces and joints on the global behavior. Two models had metallic reinforcement inside the joints. In addition, a constitutive law of the masonry defined from experimental results allowed to elaborate a simple model, which results were concordant with respect to the experimental results and similar to those calculated by complex models. Finally, two simplified models to evaluate the resistance of confined masonry walls by considering the failure plane on the wall diagonal were developed. One supposes the masonry failure by shear effect and the other supposes the masonry failure by induced tension. The ratio theoretical resistance vs. experimental resistance was adequate for walls built from different materials and tested under different loads, which had ratio Height/Length ranging from 0.74 to 1.26

Cette recherche propose des méthodes d’amélioration de résistance et d’évaluation du comportement de murs en maçonnerie confinée construits en briques solides d’argile cuite. Ces éléments sont largement utilisés dans la construction des bâtiments à l’État du Guerrero (Mexique) lesquels doivent résister charges séismiques importantes. Ainsi, un programme expérimental a été développé pour évaluer les propriétés mécaniques des briques et de la maçonnerie, qui sont nécessaires dans la conception et analyse des constructions. Pour augmenter la résistance de la maçonnerie et compenser la variabilité de la résistance à la compression des briques, un mortier à haute résistance et un renfort métallique dans les joints ont été utilisés. Certaines propriétés mécaniques sont égales à celles communément citées, cependant, les autres ont des valeurs deux fois plus grandes. Dans cette région du pays, les trois premiers tests de murs à échelle réelle construits en briques solides d’argile cuite ont été réalisés sous charge latérale alternée afin d'évaluer son comportement. Un renfort métallique et une couche du mortier ont été placés dans les surfaces de deux murs. Ceux-ci ont présenté un bon comportement et le renfort a eu un comportement structural adéquat. Avec les données expérimentales, plusieurs modèles numériques de panneaux et de murs ont été mis au point afin de reproduire l'enveloppe de résistance et le mode de défaillance. Ces modèles ont également évalué l'influence des propriétés mécaniques des briques et des joints sur le comportement global des spécimens. Aussi, un renfort métallique a été placé à l’intérieure des joints dans deux modèles. D'un autre côté, à partir de résultats expérimentaux obtenus et cités, une loi de comportement de la maçonnerie a été définie pour construire un modèle simple qui donne des résultats concordants à la fois avec les résultats expérimentaux et ceux obtenus par la méthode des éléments finis. Finalement, deux modèles simplifiés ont été proposés afin d’évaluer la résistance de murs en maçonnerie en supposant que le plan de rupture est suivant la diagonale du mur. L'un suppose la rupture de la maçonnerie par effet de cisaillement tandis que l'autre suppose la rupture par effet de tension induite. Le ratio entre résistance théorique et résistance expérimentale a été acceptable pour 27 murs faits de matériaux différents et testés sous différents types de chargement où le ratio hauteur sur longueur varie entre 0,7 et 1,26 / This research work proposes methods to rises the resistance and to evaluate the behavior of confined masonry walls built from clay solid bricks. These elements are widely used in Guerrero State (México) to build masonry structures, which should resist high lateral loads because of the serious seismic hazard. Therefore, a large experimental program to evaluate the mechanical properties of bricks and masonry currently required in the design process and masonry analysis was developed. To rises the masonry resistance and to counteract the influence of the compressive strength of the pieces on the masonry behavior, a high compressive strength mortar and a metallic reinforcement inside the joints were used. With respect to referenced values of the mechanical properties, some were similar and others were twice bigger. In this country zone, the first three tests under lateral load on full-scale confined masonry walls built from clay solid bricks were carried out in order to evaluate its behavior. A reinforcement composed by metallic hexagonal mesh-mortar coat was placed on the faces of two walls to rise or to restore the resistance. The walls showed good behavior and the reinforcement had adequate structural efficiency. Numerical models of panels and walls built by using the experimental data evaluated the envelope resistance, the failure mode and showed the influence of the mechanical properties of the pieces and joints on the global behavior. Two models had metallic reinforcement inside the joints. In addition, a constitutive law of the masonry defined from experimental results allowed to elaborate a simple model, which results were concordant with respect to the experimental results and similar to those calculated by complex models. Finally, two simplified models to evaluate the resistance of confined masonry walls by considering the failure plane on the wall diagonal were developed. One supposes the masonry failure by shear effect and the other supposes the masonry failure by induced tension. The ratio theoretical resistance vs. experimental resistance was adequate for walls built from different materials and tested under different loads, which had ratio Height/Length ranging from 0.74 to 1.26