1,720,986 research outputs found
Innovative Clay Unit Reinforced Masonry System: Testing, Design and Applications in Europe
No full textIn the framework of a recent EU funded research project, innovative construction systems for clay unit reinforced masonry walls were developed and tested. In particular, one system was developed for low-rise residential buildings, whereas the other system was aimed at building mainly tall, load bearing reinforced masonry walls for one-storey high commercial and industrial buildings.
In the first case, experimental tests were carried out to understand the cyclic in-plane behavior of real-scale walls under shear and compression. In the second case, tests were aimed at studying the cyclic out-of-plane behavior of 6 m high walls subject to P-Δ effects. Test results allowed gathering information on the efficiency of the systems, and to
check the reliability and calibrate code proposed limitations and formulations for design and assessment of such structural systems. Different types of non-linear models (a FE continuum micro-model; an analytical hysteretic model; a FE macro-model implementing non-linear moment-curvature relationships) were calibrated and used to carry out parametric analyses, to investigate the influence of various parameters
Analysis of out-of-plane behaviour of tall reinforced masonry walls under P-Δ effects
No full textIn the framework of the DISWall research project, funded by the European Commission, an innovative construction system aimed at building mainly tall, load bearing reinforced masonry walls for one-storey industrial and commercial buildings, was developed. These structures are often provided with deformable roofs and, as a consequence, out-of-plane forces can be significant in the wall behaviour and can lead to the onset of second order effects. For this structural configuration, a special set-up for out-of-plane cyclic tests was designed and built, to assess experimentally the structural behaviour and calibrate moment-curvature relationships. Non-linear static parametric analyses were carried out, aimed at studying the influence of vertical load, wall slenderness and percentage of vertical reinforcement on the wall behaviour. The present contribution describes the results of first and second order bending moment analysis and of numerical parametric assessment
Reinforced clay masonry walls: effectiveness of reinforcement and shear equations
No full textIn the framework of the DISWall project, funded by the European Commission, innovative construction systems for reinforced masonry walls were developed for the application in seismic areas. In particular, a new reinforced masonry system made with horizontally perforated clay units was developed on purpose for typical low-rise residential buildings to withstand in-plane actions. Thirty specimens of this type of masonry were characterized by means of uniaxial tests and by means of in-plane cyclic shear compression tests. In the present contribution, the effectiveness of reinforcement in the tested specimens is discussed. The tests results are compared with code proposed formulations and with newly calibrated formulations, in order to check their reliability in predicting the ultimate load capacity of reinforced masonry walls
Reinforced clay masonry walls under shear-compression loads: experimental behaviour
No full textIn the framework of the DISWall project, funded by the European Commission, innovative construction systems for reinforced masonry walls were developed for the application in seismic areas. In particular, a new reinforced masonry system made with horizontally perforated clay units was developed on purpose for typical low-rise residential buildings to withstand in-plane actions. Thirty specimens of this type of masonry were characterized by means of uniaxial tests and by means of in-plane cyclic shear compression tests. The tests were carried out on either specimens with horizontal rebar reinforcement or truss reinforcement. Furthermore, the in-plane cyclic tests were carried out on both slender and squat specimens, under different pre-compression levels, in order to force both flexural and shear failure mechanisms. In the present contribution, the results of the cyclic tests carried out are discussed. Data of steel strain on rebars and trusses, ductility parameters, energy dissipation, stiffness degradation are discussed
Out-of-plane behaviour of tall reinforced masonry walls
No full textIn the framework of the DISWall research project, funded by the European Commission, innovative construction systems, based on the use of perforated clay units and aimed at building mainly tall, load bearing reinforced masonry walls for one-storey industrial and commercial buildings, were developed. In these cases, very often buildings are provided with deformable roofs, made with prefabricated elements or glulam beams. In the case of seismic actions, deformable roofs are not able to redistribute horizontal actions to in-plane walls. Walls orthogonal to seismic load direction can be tentatively considered as cantilevers, with vertical load applied at the top and horizontal out of plane load, due to the seismic action associated to the masses of both roof and wall itself. For this structural configuration, two real scale frames, composed by two parallel reinforced masonry walls, 6 m in height, vertically loaded by steel/concrete slab, were built and subjected to cyclic tests, by applying horizontal loads at the top slab level. The aim was studying tall walls’ behaviour under out-of-plane loads and P-∆ effects. In the present contribution, results of experimental tests and analysis of bending moments are presented
Comportamento ciclico nel piano di un sistema innovativo per muratura armata
No full textNell’ambito del progetto di ricerca DISWall, finanziato dalla Commissione Europea, è stata condotta una ricerca sperimentale per caratterizzare il comportamento ciclico nel piano di un sistema innovativo di muratura armata, adatto per l’impiego in edifici di piccola-media dimensione in zona sismica.
Si sono condotte prove cicliche di compressione e taglio su pannelli di diversa dimensione, snelli e tozzi, con applicati diversi livelli di carico verticale, per studiare i due principali meccanismi di rottura, flessione e taglio, che regolano il comportamento sotto azioni orizzontali nel piano di pareti in muratura. Dall’analisi dei dati sperimentali si sono ricavate informazioni sui parametri caratteristici del comportamento sismico di pareti in muratura, inoltre è stato possibile studiare l’efficienza delle armature verticali ed orizzontali impiegate. Sulla base dei dati sperimentali ottenuti, si è affrontato quindi il problema della previsione della resistenza a taglio per pareti in muratura armata sottoposte ad azioni nel piano, tramite lo studio e la calibrazione delle più recenti formulazioni disponibili
Comportamento ciclico fuori piano di pareti alte in muratura armata: risultati sperimentali ed analisi parametriche
No full textNell’ambito del progetto di ricerca DISWall, finanziato dalla Commissione Europea, si è sviluppato un sistema costruttivo in muratura armata, basato sull’utilizzo di blocchi in laterizio, finalizzato prevalentemente alla costruzione di pareti alte per edifici monopiano a destinazione industriale e commerciale. In questo tipo di strutture, le coperture sono spesso deformabili nel loro piano, e non in grado di ridistribuire l’azione orizzontale sulle pareti di controvento. Le pareti ortogonali alla direzione del sisma possono essere schematizzate, in prima approssimazione, come mensole incastrate alla base e sollecitate, in caso di sisma, da carichi orizzontali fuori piano riconducibili alla massa della parete stessa e a quella della copertura.
Si è quindi condotta una ricerca sperimentale e numerica su pareti alte in muratura armata, sottoposte a carichi fuori piano, per valutare l’incidenza dei carichi verticali in regime di grandi spostamenti (effetti P-Δ). Nel presente contributo si discutono i risultati sperimentali delle prove cicliche fuori piano su campioni in muratura armata alti
circa 6 m. Si espongono inoltre i risultati delle analisi parametriche condotte, nelle quali si sono implementate relazioni momento-curvatura tarate sui dati sperimentali. I risultati discussi permettono di circoscrivere la problematica del comportamento fuori piano in relazione ai grandi spostamenti, individuando dei limiti progettuali
Experimental behaviour of newly developed systems for load bearing reinforced masonry walls
No full textIn the framework of a research project funded by the European Commission, innovative construction systems for load and non-load-bearing reinforced masonry walls are being developed. In particular, a new reinforced masonry system made with perforated clay units, purposely developed for low-rise residential buildings to withstand in-plane actions, based on the use of horizontally perforated clay units and concentrated vertical reinforcement, is under study for the application in areas characterized by low to high seismic hazard. This contribution presents the description of this construction system and the first experimental results obtained
Reinforced clay masonry walls under shear-compression loads: parametric analyses
No full textThe mechanical behavior of a reinforced masonry system made with horizontally perforated clay units has been characterized by means of thirty uniaxial compression and cyclic shear compression tests. The tested specimens were then numerically simulated adopting a continuum micro-model, validated on the basis of experimental results. From the comparison of the obtained results, it was possible to draw some conclusions about the test carried out and the behavior of the construction system.
The calibrated model was used to carry out parametric analyses of the tested reinforced masonry system, to investigate the influence of the applied vertical load, the geometric configuration and the reinforcement ratio on the global behavior of the tested walls. In the present contribution, the results of the finite element analyses carried out are described and discussed
Out-of-plane behaviour of tall reinforced masonry walls.
No full textIn the framework of the DISWall research project, funded by the European Commission, innovative construction systems for load and non-load-bearing reinforced masonry walls were developed. In particular, reinforced masonry systems, made with vertically perforated clay units and aimed at building mainly tall, load bearing reinforced masonry walls for factories, sport centres, commercial buildings, etc, were studied for the application in areas characterized by low to high seismic hazard. The verification of this kind of walls for out of plane loading is not completely clarified. Therefore, a specific testing program was carried out.
The tests were aimed first, at obtaining the basic mechanical characterization of the reinforced masonry system, and second, at reproducing the behaviour of reinforced masonry buildings provided with deformable roofs. In this case, the walls can be tentatively considered as cantilevers with a vertical load applied at the top and a horizontal load due to the masses of both the roof and the wall itself. To test the walls with this structural configuration, two real scale frames, composed by two parallel reinforced masonry walls, 6 m high, vertically loaded by means of a heavy steel/concrete slab, were built and subjected to cyclic out-of-plane tests, by applying a horizontal load at the level of the top slab. In the present contribution, the first results of the experimental tests are presented and discussed
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