Em projetos de alvenaria estrutural é indispensável à verificação de elementos submetidos à flexão simples, como vigas, vergas, reservatórios e muros de arrimos. Neste trabalho foram analisados oito grupos de vigas, compostos por três exemplares cada um, diferenciando seu comprimento, altura, tipo da unidade (blocos de concreto e blocos cerâmicos) e taxa de armadura. Os traços de graute e argamassa foram mantidos. As vigas e as armaduras longitudinais foram instrumentadas para obtenção dos deslocamentos e deformações. A finalidade do trabalho foi realizar uma comparação dos resultados obtidos através de ensaios experimentais com os dimensionamentos propostos pelas normas ABNT NBR 15812-1:2010 e NBR 15961-1:2011. Foi possível observar que o dimensionamento proposto pelas normas é conservador, pois limita o comportamento à flexão das vigas em cargas baixas quando comparados com experimentais. Já com a retirada dos coeficientes de segurança pode ocorrer, em alguns casos, que a carga teórica prevista seja maior que a dos resultados experimentais. A formulação adaptada da NBR 6118:2007 para obter valores de deslocamentos apresentou uma boa correlação para as vigas de uma fiada. Já para as vigas de duas fiadas observou-se uma pior correlação entre valores teóricos e experimentais, sendo os deslocamentos teóricos menores que os valores medidos experimentalmente. / In structural masonry projects is essential to verify elements subjected to simple bending, such as beams, lintels, water tanks and retaining walls. In this study, an experimental parametric analysis was conducted. Eight groups of beams composed by three specimens were tested and the parameters varied were: length, height, unit type (concrete blocks and ceramic blocks) and reinforcement ratio. The proportion of grout and the mortar were fixed. The beams and longitudinal bars were instrumented to obtain the displacements and strains. The purpose of this study was to compare the results obtained through experimental analysis with the proposed methods presented on ABNT NBR 15812-1:2010 and NBR 15961-1:2011. In the comparison was observed that the proposed design method is conservative, due to the limit load obtained by the code prescriptions was lower than the experimental results. In some cases, the theoretical load results were greater than experimental results when the safety factors were removed. The adapted formulation of the NBR 6118:2007, to obtain displacement values, showed a good correlation to the beams of one row. Regarding to beams with two rows, the correlation between experimental and theoretical values was not suitable, the theoretical displacements presented smaller than the values measured in the tests.

Este trabalho apresenta modelos numéricos em elementos finitos, elaborados com o auxílio do programa ANSYS 5.5, de paredes de alvenaria estrutural apoiadas em vigas de concreto armado. São estudados diversos modelos possíveis de serem utilizados, inclusive com a consideração das não-linearidades de contato, ou seja, a separação e o deslizamento que tendem a ocorrer na interface parede-viga por ocasião do efeito arco. Para tanto, são introduzidos elementos de contato nesta interface. Os resultados obtidos são comparados entre si e também com resultados experimentais encontrados na literatura, de modo a se avaliar as características positivas e negativas de cada procedimento. / This work describes numerical procedures using ANSYS 5.5 program for modeling masonry walls supported by reinforced concrete beams. Several available procedures for this case are studied, including or not, non-linear effects that can occur at the boundary surface between the masonry wall and the concrete beam, because of the arch effect. So, obtained results for these numerical models are compared among themselves and with experimental results found in papers, in order to obtain some information about their acuity.

Este trabalho trata de fissura, uma das principais patologias que podem ocorrer em edifícios residenciais em alvenaria estrutural, visando identificar os locais onde elas aparecem com mais frequência, para assim procurar formas de evitá-las. Inicialmente foram realizadas visitas a vários edifícios em alvenaria estrutural de forma a levantar as principais fissuras encontradas nesse tipo de estrutura. Identificou-se que as fissuras são mais frequentes nos contornos de aberturas, diante disse foi realizado um estudo teórico, com a utilização de um programa computacional, para se determinar algumas das principais causas prováveis dessas patologias através de modelos numéricos adequados. Finalmente, foram analisadas algumas das soluções para as patologias encontradas, tentando sugerir as melhores soluções para cada caso. / This paper deals with fissure, one of major diseases that can occur in a structural masonry residential buildings, in order to identify the locals they usually occur, to seek ways to avoid them. Initially were realized visits a several structural masonry buildings to analise the principals fissures in this type of structure. Was identified that the fissures are more frequently in the contours of openings, given this, was realized a theoretical study using a finite element computer program to identify some of the main possible causes of these pathologies through adequate numerical models. Finally, some possible solutions for the conditions found were analyzed, trying to suggest the best solutions for each case.

O presente trabalho é um estudo teórico e principalmente experimental sobre paredes de alvenaria de blocos cerâmicos. Inicialmente, estão apresentados alguns fatores que contribuem na resistência à compressão da alvenaria, mecanismos de ruína e prescrições para dimensionamento à compressão segundo algumas normas mais utilizadas. Em seguida, é apresentada uma compilação de vários resultados de ensaios à compressão de paredes de alvenaria estrutural de blocos cerâmicos realizados em diversos centros de pesquisa no Brasil. Depois, são apresentados procedimentos e resultados de diversos ensaios com unidades, prismas e paredes de alvenaria estrutural de blocos cerâmicos, com e sem graute. Todos esses ensaios foram realizados especialmente durante este trabalho de pesquisa com o intuito de confirmar e ampliar os conhecimentos adquiridos com a compilação de resultados anteriormente mencionada. Por fim, foram modeladas, numericamente, paredes com e sem graute visando, principalmente, obter-se informações sobre as melhores opções para a discretização de estruturas desse tipo. / This work deals with a theoretical and experimental study about clay masonry walls under compression. First, main factors that may cause influence on compressive capacity of walls, failure mechanisms and main codes used in Brazil are presented in order to discuss theoretical aspects of the phenomenon. After that, several experimental results obtained from many different researchers in Brazil, including results obtained for grouted walls by this work, are shown. These results are presented in order to obtain an overview about compressive strength of clay masonry walls with and without grout. So, important relationships among units, prisms and walls are established. Finally, the work presents some numerical models for walls with and without grout.

O presente trabalho apresenta os resultados obtidos na pesquisa sobre o uso de revestimentos resistentes de argamassas de cimento e areia na reabilitação de paredes de alvenaria, quando solicitadas à compressão axial, compressão diagonal e flexão de painéis. Os ensaios foram baseados nas normas NBR 8949, ASTM 519 e NBR 14322 respectivamente. O objetivo dos ensaios realizados foi observar o comportamento estrutural de paredes de blocos de concreto revestidas com diversos tipos de argamassa de cimento e areia, os quais resultaram de combinações de argamassa de resistência baixa ou mais elevada, telas de aço soldadas, fibras de aço, fibras de polipropileno e conectores de cisalhamento. Os modelos dos ensaios de compressão axial tinham dimensões de 39 x 81 cm e foram confeccionados em gabaritos de aço para uma maior precisão durante o assentamento. Para os ensaios de compressão diagonal foram idealizados gabaritos de madeira para confecção e transporte dos modelos cujas dimensões eram de 80 x 80 cm. Nos ensaios de flexão as paredes (80 x 1,60) foram ensaiadas com a face maior na posição horizontal com duas situações de carregamento. Depois de terminados estes ensaios e analisados os resultados foi realizada também uma série de ensaios sobre painéis de alvenaria, submetidos a forças distribuídas numa região pequena do topo da parede e ensaiados em três situações diferentes: paredes íntegras, reabilitadas e reforçadas. A decisão de ensaiar painéis com aberturas se deu pela intenção de criar situações de desvio de tensões no plano da parede, provocando esforços de compressão, tração e cisalhamento. Todos os ensaios foram realizados com uso de equipamento hidráulico servo-controlado INSTRON, controlando-se a velocidade de deslocamento, o que permitiu observar o comportamento das paredes após à sua resistência de pico. Pode-se dizer que a técnica em estudo apresenta diversos aspectos interessantes, que podem ser explorados tanto na reabilitação (reforço ou reparo) de estruturas de alvenaria, como na execução de estruturas novas com exigências especiais de desempenho. / This paper reports on the results of a study about the use of resistant overlays of cement and sands mortars in the rehabilitation of masonry walls subjected to axial and diagonal compression and flexure. The tests were carried out according to the NBR8949, ASTM 519 and NBR 14322 codes. The purpose of the tests was to observe the structural behavior of concrete block walls covered with several combinations of materials: plain mortar with two different strengths, welded steel mesh, steel fibers, polypropylene fibers and shear connectors. The dimensions of the specimens subjected to axial compression tests were 390 x 810 mm. They were built inside steel templates for a better precision during their construction. Wooden templates were set up for the diagonal compression tests to build and transport the 800 x 800 mm specimens. In the flexure tests, the walls (800 x 1600 mm) were tested with the larger side in the horizontal position, using two loading situations. After the conclusion of these tests and an analysis of the results, a series of tests was carried out on masonry panels subjected to loads distributed over a small area at the top of the wall. Three different situations were tested, i.e., undamaged walls, rehabilitated walls and reinforced walls. The decision to test panels with openings was based on the idea of creating situations to deviate the stresses in the plane of the wall, thereby inducing compression, tension and shear. All the tests were performed using an universal servo-controlled INSTRON machine to control the displacement speed, allowing the observation of the behavior of the walls after their peak resistance. Based on this study, it can be stated that this technique offers several interesting aspects that may be applied both in the rehabilitation (strengthening or repair) of masonry structures and in the construction of new structures with special performance requirements.

O presente trabalho é um estudo teórico e principalmente experimental sobre paredes de alvenaria de blocos cerâmicos. Inicialmente, estão apresentados alguns fatores que contribuem na resistência à compressão da alvenaria, mecanismos de ruína e prescrições para dimensionamento à compressão segundo algumas normas mais utilizadas. Em seguida, é apresentada uma compilação de vários resultados de ensaios à compressão de paredes de alvenaria estrutural de blocos cerâmicos realizados em diversos centros de pesquisa no Brasil. Depois, são apresentados procedimentos e resultados de diversos ensaios com unidades, prismas e paredes de alvenaria estrutural de blocos cerâmicos, com e sem graute. Todos esses ensaios foram realizados especialmente durante este trabalho de pesquisa com o intuito de confirmar e ampliar os conhecimentos adquiridos com a compilação de resultados anteriormente mencionada. Por fim, foram modeladas, numericamente, paredes com e sem graute visando, principalmente, obter-se informações sobre as melhores opções para a discretização de estruturas desse tipo. / This work deals with a theoretical and experimental study about clay masonry walls under compression. First, main factors that may cause influence on compressive capacity of walls, failure mechanisms and main codes used in Brazil are presented in order to discuss theoretical aspects of the phenomenon. After that, several experimental results obtained from many different researchers in Brazil, including results obtained for grouted walls by this work, are shown. These results are presented in order to obtain an overview about compressive strength of clay masonry walls with and without grout. So, important relationships among units, prisms and walls are established. Finally, the work presents some numerical models for walls with and without grout.

Earthquakes represent a serious threat to the safety of masonry structures, with failure of these constructions under the influence of seismic action generally occurring via specific, well-documented collapse mechanisms. Analysis and assessment of these collapse mechanisms remains a challenge - while most analysis tools are time-consuming and computationally expensive, typical assessment methods are too simplified and often tend to underestimate the dynamic resistance of the structures. This dissertation aims to bridge the gap between the two through the development of a computational tool for the seismic collapse assessment of masonry structures, which uses rocking dynamics to accurately capture large displacement response, without compromising on computational efficiency. The tool could be used for rapid evaluation of critical mechanisms in a structure in order to prioritise retrofit solutions, as well as for code-based seismic assessment. The framework of the tool is first presented, wherein the rocking equations of motion are derived for a range of different collapse mechanisms, for any user-defined structural geometry, using as a starting point a geometric model of the structure in Rhino (a 3D CAD software). These equations of motion are then exported for solution to MATLAB. As a number of collapse mechanisms take place above ground level, a methodology to account for ground motion amplification effects is also proposed, while in the case of comparison of multiple different mechanisms, an algorithm to automatically detect critical mechanisms is presented. These developments make it possible to rapidly conduct a seismic analysis of structures with complicated three-dimensional geometries. However, the rocking equations of motion utilised thus far assume that the interfaces between the masonry macro-elements are rigid, which is not the case in reality. Thus, a flexible interface model is introduced, where the interfaces are characterised by a finite stiffness and compressive strength. This modelling strategy results in an inward shift of the rocking rotation points, and expressions are derived for these shifting rotation points for different interface geometries. The rocking equations of motion are also re-derived to account for the influence of the continuously moving hinges. However, the new equations tend to be highly non-linear - especially in the case of more complex collapse mechanisms. Thus to reduce computational burden, the semi-flexible interface model is proposed, which accounts for the shifting hinges in a more simplified manner than its fully-flexible counterpart. These new analytical models enable more accurate prediction of the seismic response of real-world structures, where interface flexibility tends to have a significant influence on dynamic response, while material damage in the form of crushing of the masonry also reduces dynamic resistance. The ability of the tool to be used for both seismic analysis and assessment is finally demonstrated by using it to perform a rocking dynamics-based analysis as well as a code-based seismic assessment of the walls of a historic earthen structure.

Construction practices are constantly evolving in order to adapt to physical locations and economic conditions. These adaptations may result in more cost-effective designs, but may also come at a cost of strength. In masonry shear walls, it is becoming more common to reduce the amount of grouting from every cell to only those with reinforcement, a practice known as partial-grouting. Partially-grouted masonry responds differently and in a more complex matter to lateral loads as compared to fully-grouted masonry. The response is made even more complex by wall discontinuities in the form of openings. The main objective of this study is to validate the strut-and-tie procedure for the in-plane lateral strength prediction of partially-grouted, multistory, reinforced concrete masonry walls with openings. The research included testing six three story, half-scale masonry shear walls. Half of the walls had door openings while the other half had window openings. The configurations were selected to represent typical walls in multi-story buildings. The measured lateral strength was compared to estimations from the equations in the US masonry code and to those from an equivalent truss model and a strut-and-tie model. The results show that the U.S. masonry code equations over predicts while the equivalent truss model under predicts the lateral strength of the walls. The results further show that the strut-and-tie model is the most accurate method for lateral strength prediction and is able to account for wall openings and partial-grouting.

Masonry is one of the oldest forms of construction materials that is still in use today. However, construction practices in the modern age demand faster and more economical practices. Dry-stack masonry, or masonry that doesn't use mortar to bind the blocks together, is a unique system to make masonry more economical. Though several systems of dry-stack masonry have been suggested little to no data exists as most of these systems are patented. This research used dry-stacked normal weight concrete masonry units with an eccentrically placed reinforcement. The wall system is connected through a surface bond and lacks any geometric connection. Previously, research has been conducted on the wall system for its axial compressive capacity, but little information is known about its ability to withstand lateral forces such as earthquakes. Research was conducted on the wall system in order to determine the seismic parameters, including the force reduction factor, overstrength factor, and the displacement amplification factor. To determine these factors the guidelines from the Federal Emergency Management Agency (FEMA) Quantification of Building Seismic Performance Factors 2009 were followed. The guidelines are explicit that both experimental data and computer modeling are needed to quantify these parameters. Experimental data was obtained from a diagonal tension test, and an in-plane shear test. The diagonal tensions test provided preliminary values on the shear modulus and shear resistance. The in-plane shear test was of primary interest and what would be used to verify the computer model. Computer modeling of the wall system was accomplished with Vector 2. Initially the computer modeling was done to reproduce experimental data. Then, a parametric study was performed using the model to see what component of the wall most effected its capacity. This analysis showed that the surface bond was the component of the wall that most affects its capacity. Finally, the computer model was run through the FEMA Far-Field earthquake suite to gather data on the strength and ductility. Values of the force reduction factor, overstrength factor, and displacement amplification factor were determined based on the time history analysis and pushover analysis on the computer model.

The use of self-consolidating grout in reinforced masonry construction provides various advantages such as reduced labor, faster construction, decreased noise pollution and better structural response. This is a relatively new building material however, and little research on self-consolidating grout's structural properties has been conducted. The purpose of this study was to analyze the performance or bond capacity of steel reinforcing bar splices in masonry with self-consolidating grout. Twelve masonry panels approximately 40 in. wide and 32 in. tall consisting of Type S mortar and concrete masonry units grouted with self-consolidating grout and No. 5 steel reinforcing bars were constructed with splice lengths as prescribed by the current design equation and splices that were slightly shorter. Test Group 1 consisted of six reinforced masonry panels with the code required lap length while Test Groups 2 and 3 had splices two and four inches shorter, respectively. The lap-splices were tested in pure tension to determine if they would fully develop the code mandated stress of 125% of the specified yield strength of the reinforcing bars. More samples were tested with the code required development length to verify if the current provision is adequate for design and the other two groups were used to explore if the required capacity could be achieved with shorter splices. All lap-splices developed the minimum required stress, even those with splices shorter than required by the design equation. For masonry with self-consolidating grout containing No. 5 bars in the specific configurations tested, the current design equation was shown to be adequate for calculating development length. Testing indicates that a reduction in required splice length for masonry with self-consolidating grout is possible.