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Innovative masonry strengthening techniques maintaining the original brickwork appearance: An overview
No full textIn many seismically active regions, historical masonry buildings represent a significant portion of the building heritage. These structures very often are characterised by masonry that presents low mechanical properties, due both to its texture and to the bad mechanical characteristics of the mortar. If we want to preserve this heritage the use of strengthening methods is necessary and, consequently to an increasing interest in the conservation of historic construction, the interest in new strengthening techniques is nowadays greater. In fact, in the past, “conventional” techniques-as grout injections or concrete external reinforcement – were more common, but these systems have shown problems over time in terms of effectiveness and durability. Recently new reinforcement materials were introduced to the world of restoration like Fibre Reinforced Polymers (FRP) or Fibre Reinforced Cementitious Matrix (FRCM), which are made of synthetic fibres embedded in resins or mortar, respectively. However, where maintaining the original aspect of the facing-masonry is essential, all the previous techniques seem to be unsatisfactory. In this paper, is presented a review of the innovative techniques that have been recently proposed to solve this problem, in order to facilitate the role played by designers in restoration and rehabilitation interventions
Tehcnological analysis, typological features and seismic vulnerabilities of post-World War II Italian school buildings
No full textMany Italian school buildings, built just after the post-World War II, share similar geometrical and spatial characteristics. Some of these features may negatively affect the building seismic response, generating typical seismic vulnerabilities. In order to mitigate them, and then to foster an effective transition towards a safer and more sustainable society, it is important to provide exemplary cases on how to proceed correctly. For this reason, in this paper typical vulnerabilities of Italian post-World War II RC school buildings are individuated and discussed. For one of the most representative case study an in situ experimental campaign has been carried out in order to identify the specific seismic vulnerabilities related to specific geometrical aspects or material properties. Results of structural assessment have evidenced that some typological vulnerabilities such as wide atriums, eccentric stairs and tall windows, along with irregularity in plan configuration, strongly affect the global seismic behavior of the school buildings. Finally, a structural intervention aimed to improve the performance against seismic actions has been proposed and described for the case study. The intervention concerned RC jacketing of the columns, shear strengthening of beams through Carbon Fiber Reinforced Polymers (CFRP) sheets and strengthening of the beam-columns joints. The strengthening efficiency has been evaluated by means of pushover analysis. The proposed intervention can improve the seismic resistance of the building
Miglioramento sismico della scuola “Puccini” in Senigallia. Dalla diagnosi all’intervento
No full textQuesto articolo riporta l'esperienza dell'intervento progettato ed eseguito sull'edificio scolastico "Puccini" in Senigallia, il quale presenta caratteristiche architettoniche e vulnerabilità sismiche tipiche di edifici scolastici costruiti in Italia nel secondo dopoguerra. La scuola, insieme ad altre localizzate sempre nel Comune di Senigallia, ed aventi caratteristiche simili a livello di materiali e tecnologia costruttiva, è stata oggetto di studio ed analisi approfondite nell'ambito della convenzione di ricerca scientifica stipulata tra l'Università Politecnica delle Marche e il Comune di Senigallia inerente ''La valutazione e la stesura di linee guida per la riduzione del rischio sismico dell'edilizia scolastica del dopo guerra"
Experimental assessment of concrete compressive strength in old existing RC buildings: a possible way to reduce the dispersion of DT results
No full textReliable appraisal of the in situ compressive strength is a key challenge in the seismic assessment of existing RC structures, due to its high variability throughout them and because it often represents the most important strength parameter adopted in the structural analyses. For this reason, in this paper a procedure to obtain a more accurate concrete strength characterization is proposed and applied to several case studies. The method provides a reduction of test results’ variability by taking into account the influence of casting operations on it and may support existing codes for a correct in-place concrete strength evaluation
Diagnosis and structural assessment of the assumption of the virgin mary chapel in Prague (CZ)
No full textThis paper illustrates the results of the analysis and the structural assessment of the Assumption of the Virgin Mary chapel, in Prague. The chapel, an oval-shaped building covered with a dome, was built at the end of the 16th century and can be considered the last example of renaissance architecture and, at the same time, the first example of baroque architecture in Prague: it is a significant testimony of the close connection between local artists and their Italian teachers. The building has been closed to visitors during the last decades for the presence of some structural damages and because it was severely degraded due to lack of maintenance. It was reopened in 2017 after a notable restoration process. This paper pays attention to the interdisciplinary approach used for structural assessment of the chapel, that is based on the activities of the “knowledge path,” the subsequent structural analysis and the intervention design. Particular attention was paid to the contribution of the historical review, geometric laser scanner survey and mechanical characterization of the structural materials. All these steps are necessary to identify potential vulnerabilities and to enable the understanding of the effective structural models, also in view of proposing adequate retrofit solutions. A numerical model of the chapel was prepared and calibrated. Finally, the structural assessment for static and seismic condition was performed
Extraperitoneizzazione del condotto ileale in corso di cistectomia radicale laparoscopica:ns esperienza
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