Search results for " Masonry"
showing 10 items of 76 documents
Constructive characters of the Western Sicilian masonry in the XVIII and XIX centuries
2016
La tradizione costruttiva di apparecchi murari nella Sicilia occidentale - soprattutto a causa dei frequenti terremoti che si verificarono a Palermo tra i secoli XVIII-XIX (il più distruttivo avvenuto nel 1726, seguito da quelli del 1751, e 1823) - impose la realizzazione di nuovi tipi di muratura che, nel rispetto dei precetti della regola dell'arte, suggeriscono metodi più severi di quella che si può definire la "buona" costruzione muraria, sia nella scelta dei materiali che nell'adozione di nuove tecniche costruttive. La cultura tecnica di quel tempo era in grado di definire metodi costruttivi, introducendo appropriati miglioramenti e sperimentazioni, che promossero nuove conoscenze, tec…
An experimental study on the compressive behaviour of calcarenite masonry columns wrapped by fiber reinforced mortar wraps
2018
The use of Fiber Reinforced Cementitious Mortar (FRCM) systems for structural retrofitting of masonry structures has become increasingly popular in the last years, due to the capability of this technique in overcoming some of the drawbacks related to the adoption of resin-based composites. In fact, FRCM systems ensure good compatibility between the reinforcing layers and the substrate, achieving also the removability requirement, which is of fundamental importance for historical constructions. Recent research studies focused on the mechanical performance of FRCM materials, by studying its tensile behaviour and bond between the strengthening layer and masonry, pointing out as failure is alwa…
Empirical Equations for the Direct Definition of Stress–Strain Laws for Fiber-Section-Based Macromodeling of Infilled Frames
2018
Equivalent strut macromodels are largely used to model the influence of infill walls in frame structures due to their simplicity and effectiveness from a computational point of view. Despite these advantages, which are fundamental to carrying out seismic simulation of complex structures, equivalent struts are phenomenological models and therefore have to conventionally account for the influence of really large amounts of geometrical and mechanical variables with a relatively simple inelastic response. Mechanical approaches, generally used to evaluate the force-displacement curve of a strut, are based on hypothesizing the damage mechanism that will occur for an infill-frame system subject to…
Bòvedas tabicadas: experimental and numerical analysis
2008
A class of thin vaults, the so-called “bovedas tabicadas”, which represent one of the most common Spanish traditional building techniques at the end of XIX century are studied here, treating the relevant analysis problem through a numerical, as well as an experimental, approach. At first the problem is studied by searching for the behaviour of the material effecting suitable experiments. Once the constitutive behaviour of the materials and the structural elements are experimentally characterized, a semi inverse method for the identification of the optimum mechanical parameters to assign to an equivalent homogeneous ideal material through analysis reproducing the executed experimental tests …
Evaluation of Flat Jack Test Method Effectiveness for Masonry Structural Investigations
2019
Flat jack testing method is one of the most commonly used techniques for the structural assessment of existing masonry structures. Single and double flat jack are commonly adopted to evaluate the acting normal stress, or the compressive behaviour of masonry material. Test procedures are codified by international standards (e.g. A.S.T.M D4729-87; C1196-04; C1197-04, R.I.L.E.M TC 177–MDT D.4; R.I.L.E.M. TC 177–MDT D.5), which provide the preliminary calibration of an experimental coefficient (km), which determination influences significantly the reliability of the test. This paper presents the result of an experimental study on the calibration of km coefficient for flat jacks. The problem is …
A FE-Meshless Multiscale Approach for Masonry Materials
2015
Abstract A FE-Meshless multiscale computational strategy for the analysis of running bond masonry is presented. The Meshless Method (MM) is adopted to solve the boundary value problem (BVP) at the mesoscopic level. The representative unit cell is composed by the aggregate and the surrounding joints, the former assumed to behave elastically while the latter are simulated as non-associated elastic-plastic zero-thickness interfaces with a softening response. Macroscopic localization of plastic bands is obtained performing a spectral analysis of the tangent stiffness matrix. Localized plastic bands are embedded into the quadrature points area of the macroscopic finite elements.
Compressive behaviour of eccentrically loaded slender masonry columns confined by FRP
2018
Abstract Fibre Reinforced Polymer (FRP) confinement represents an effective tool for retrofitting masonry piers or columns enhancing their structural performance. This technique has been widely studied in the literature mainly with reference to short columns, while no extensive information is available on the influence of second order effects on its efficacy in case of slender members. Within this framework, the presented study concerns a simplified method able to assess the effects of FRP confinement on the compressive behaviour of slender masonry columns. A proper constitutive law of FRP confined masonry in compression is adopted for performing a sectional analysis, in which also consider…
Mesoscopic aspects of the computational homogenization with meshless modeling for masonry material
2020
The multiscale homogenization scheme is becoming a diffused tool for the analysis of heterogeneous materials as masonry since it allows dealing with the complexity of formulating closed-form constitutive laws by retrieving the material response from the solution of a unit cell (UC) boundary value problem (BVP). The robustness of multiscale simulations depends on the robustness of the nested macroscopic and mesoscopic models. In this study, specific attention is paid to the meshless solution of the UC BVP under plane stress conditions, comparing performances related to the application of linear displacement or periodic boundary conditions (BCs). The effect of the geometry of the UC is also i…
Use of FRP fabrics and stainless steel grids for strengthening brick masonry columns
2016
This work presents the results of an experimental investigation on 42 solid clay brick columns internally strengthened by FRP fabrics or stainless steel grids placed in the horizontal joints of mortar. Monotonic compressive loading tests were carried out under concentric and eccentric load. Eccentric tests were carried out loading the specimens on a reduced area with respect to the entire crosssection producing a D-region. The reinforcing of every course and of alternate courses are studied. The effectiveness of the proposed strengthening techniques is discussed, in terms of increase in strength and energy required to the collapse of brick columns. An analytical expression is proposed that …
Seismic Performance of Masonry Infilled RC Structures via N2 Pushover Assessment Procedures: Outcomes under Different Modeling Hypotheses of a Case S…
2016
The assessment of the capacity of RC masonry infilled RC structures constitutes nowadays a still debated issue. Pushover based procedures for the evaluation of seismic performance, such as N2 method, are largely used in practice and in force in several technical codes. The latter has proved to be reliable for a large number of structural typologies, however in the case of infilled frames, the choices made on the modelling strategy may radically modify the outcomes observable from the capacity curves and the consequent performance levels achievable. In the paper, the extent of different modelling choices on the results of the application of N2 procedure is investigated by the deep analysis o…