Compressive and shear behaviour of masonry panels: experimentation and numerical analysis

The compressive and shear behavior of masonry is here studied both experimental- ly and numerically. An experimental campaign has been carried out on 9 square-shaped one leaf masonry panels, reproducing historical masonry. Tests have been done for evaluating the elastic and shear moduli in both plane directions, with 6 panels rotated by 90 degrees, lead- ing to vertically aligned bed joints, and 3 panels maintained with horizontal bed joints. Com- pressive tests were executed on 6 masonry panels, 3 of them rotated by 90 degrees. Initial shear strength and shear modulus parallel to bed joints are evaluated through shear tests on 9 masonry triplets. Shear tests are performed on 3 rotated panels, applying an horizontal dis- tributed load, without vertical compression. Attention is paid to the service load state: only the initial phase of the tests is studied. Numerical models are proposed for representing actu- al masonry behavior, both discrete [1] and continuous [2,3], standard and micropolar, ob- tained by homogenization procedures [4]. Several numerical analyses are performed for simulating the experimental tests on masonry triplets and panels. The mechanical elastic pa- rameters of both discrete and continuous models are calibrated starting from laboratory data of masonry constituents and then by fitting the results of the initial phases of the experimental tests on masonry specimens

Out-of-plane dynamic response of a tuff masonry wall. Shaking table testing and numerical simulation

The out-of-plane dynamic response of a masonry element is investigated, both experimentally and numerically. The results of shaking table tests on a tuff masonry wall, subjected to harmonic acceleration histories, are presented. An isotropic nonlocal damage-plastic model, accounting for the masonry strength-stiffness degrading and hysteresis mechanisms, is introduced in a finite element procedure to numerically describe the masonry structural response. A simplified scheme is analysed, where the wall is completely restrained at the base and free at the top. The measured top displacement history is compared with that numerically evaluated, obtaining a satisfactory agreement. Moreover, the effects of the onset and evolution of the degrading mechanisms in the masonry wall are highlighted

An Experimental Study on the Effect of Water on Historic Brickwork Masonry

Architectural heritage is deeply threatened by extreme weather events due to ongoing climatic change. Since these phenomena are becoming more and more serious, their effects cannot be neglected when a reliable assessment of a historic masonry structure is required. In this paper, the phenomenon of rising damp was studied, focusing on the influence of water on the unit weight of masonry walls made from fired clay bricks and lime mortar. This study consists of a basic experimental research on the variations in the unit weight of masonry undergoing an ageing treatment, which was simulated through some cycles of capillary water absorption and temperature changes. The experimental study proves that penetrating damp causes an increase in masonry unit weight of more than 20%. This basic result is significant in the structural assessment of historic masonry buildings. Subsequent papers will analyze the interaction with strengths parameters

Micro-Assembly using Elastomeric Surfaces with Switchable Dry Adhesion

This work presents a micromanufacturing method for constructing microsystems, which we term ‘micro-masonry’ based on individual manipulation, influenced by strategies for deterministic materials assembly using advanced forms of transfer printing. Analogous to masonry in construction sites, micro-masonry consists of the preparation, manipulation, and binding of microscale units to assemble microcomponents and microsystems. We used microtipped elastomeric stamps as manipulators and built three dimensional silicon microstructures [1]. Silicon units of varied shapes were fabricated in a suspended format on donors, retrieved, delivered, and placed on a target location on a receiver using microtipped stamps. Annealing of the assembled silicon units permanently bound them and completed the micro-masonry procedure

Brick and Concrete Masonry

Describes the various materials used in brick and concrete masonry construction: some of the more common masonry systems, and the details that go into making rna onry walls strong durable and weather-resistant

Finite-discrete element modelling of masonry infill walls subjected to out-of-plane loads

In this paper, the out-of-plane response of infill walls is investigated by means of non-linear monotonic (push-over) analyses through a combined finite and discrete modelling approach. The model accounts for material deformability, crack formation, sliding, separa-tion and formation of new contacts. Masonry units are modelled as finite elements, and differ-ent material models are assumed for the masonry. Contact between masonry units, and between masonry and frame elements is modelled by means of interfaces, which permit tan-gential motion with frictional sliding. Frame elements are modelled by means of a linear-elastic material. The results of the numerical analyses are compared with those of experimen-tal tests available in the literature. The advantages and disadvantages of the adopted model-ling strategy are investigated

Calibration of a visual method for the analysis of the mechanical properties of historic masonry

The conservation and preservation of historic buildings affords many challenges to those who aim to retain our building heritage. In this area, the knowledge of the mechanical characteristics of the masonry material is fundamental. However, mechanical destructive testing is always expensive and time-consuming, especially when applied to masonry historic structures. In order to overcome such kind of problems, the authors of this article, proposed in 2014 a visual method for the estimation of some critical mechanical parameters of the masonry material. Based on the fact that the mechanical behavior of masonry material depends on many factors, such as compressive or shear strength of components (mortar and masonry units), unit shape, volumetric ratio between components and stone arrangement, that is the result of applying a series of construction solutions which form the "rule of art". Taking into account the complexity of the problem due to the great number of variables, and being on-site testing a not-always viable solution, a visual estimate of the mechanical parameters of the walls can be made on the basis of a qualitative criteria evaluation. A revision of this visual method is proposed in this paper. The draft version of new Italian Building Code have been used to re-calibrate this visual method and more tests results have been also considered for a better estimation of the mechanical properties of masonry

Numerical modelling of in-plane behaviour of adobe walls

Some tests for material characterization of adobe blocks and adobe masonry have been carried out in universities and laboratories around the world. However, the number of tests is quite limited in comparison with those carried out with other structural materials, such as masonry or reinforced concrete, and even those tests just refers to elastic properties. The results of adobe tests (i.e. compression strength, elasticity modulus, shear strength, etc.), as well as the results of cyclic and dynamic tests on adobe masonry components and small buildings show that the mechanical properties of adobe masonry and the seismic performance of adobe constructions highly depend on the type of soil used for the production of units and mortar. Basic properties, such as elasticity modulus, can have significant variation from one soil type to another. The state-of-the-art for the numerical modelling of unreinforced masonry point to three main approaches: macro-modelling, simplified micro-modelling and detailed micro-modelling. In all three approaches, the use of elastic and inelastic parameters is required. For adobe masonry, the lack of knowledge concerning some of the material properties makes numerical modelling more difficult. In the proposed work, the mechanical properties of the typical adobe masonry in Peru have been calibrated based on a cyclic in-plane test carried out on an adobe wall at the Catholic University of Peru (PUCP). The mechanical parameters calibration and the modelling results of the in-plane behaviour of the adobe wall are presented. Macro-modelling and simplified micro-modelling strategies are used in finite element software with an implicit solution strategy. The results of this work represent the first step for the numerical modelling of the seismic behaviour of adobe constructions

Study of the compressive response of masonry using non-conventional joint materials

Winner of the International Journal of Masonry Research and Innovation IJMRI Best Paper Award 2017The compressive response of masonry is influenced by geometric, material and execution variables. In addition, the nature of bricks and mortar typically introduces uncertainty to the experimental results. In order to reduce this uncertainty, an experimental campaign has been carried out to analyse the influence of the properties of the joints. Four non-conventional masonry typologies including resin, EPS and rubber joints have been considered for this purpose. In all, 60 compressive tests and 50 deformability tests on five stacked bricks prisms were performed. Obtained data are compared with data from the literature. A comparison with the current European standard is also carried out. The obtained results point out that the modulus of linear deformation of the joint is the most influent variable on the compressive response of masonry. Finally, it seems that current formulation (Eurocode-6) tends to overestimate the modulus of linear deformation of masonry.Peer ReviewedAward-winningPostprint (author's final draft

unreinforced masonry buildings

A recent earthquake of M=4.9 occurred on 29 October 2007 in C, ameli, Denizli, which is located in a seismically active region at southwest Anatolia, Turkey. It has caused extensive damages at unreinforced masonry buildings like many other cases observed in Turkey during other previous earthquakes. Most of the damaged structures were non-engineered, seismically deficient, unreinforced masonry buildings. This paper presents a site survey of these damaged buildings. In addition to typical masonry damages, some infrequent, event-specific damages were also observed. Reasons for the relatively wide spread damages considering the magnitude of the event are discussed in the paper