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Simplified and refined analyses for seismic investigation of historical masonry clusters: Comparison of results and influence of the structural units position
Full text linkExperimental Tests on Cement Mortars Manufactured with Hemp Flour
Full text linkAim:
Currently, research and market needs are aimed at the production of more and more specific mortars and concrete with the best properties and mix
design directed towards increasingly specific uses.
Background:
This research starts with a discussion on cement and aggregate assortments, which are the basic properties of mortars.
Objective:
The choice of suitable additives able to correct the rheological, workability and resistance properties of the mixture is focused.
Methods:
In this framework, the current research activity involves some experimental laboratory tests on cement mortars manufactured with hemp flour,
intended as a “natural” additive. The aim is the search for any improvements given by the hemp flour to the physical and/or mechanical
performances of the tested mortars.
Results:
Hemp flour, due to bonding properties, increases the compactness, and therefore, the resistance to environmental factors by the examined cement
mortars. The rheological features of mixtures with different percentages of hemp flour, whose maximum water percentage absorbed was resulted to be 125%, were investigated. It was found that standardised sand reduces shrinkage phenomena of tested specimens. Moreover, the compression
and bending moment behaviour of manufactured specimens was analysed with the aim of finding the optimal weight percentage of hemp flour to
improve their mechanical performances.
Conclusion:
The experimentation performed leads to several conclusions and interesting future developments. It was found that 3% is the best-weighted
percentage of hemp flour to increase the mechanical properties of examined mortars made of standardised sand. As further developments, there is a
need to identify the limit percentage of hemp flour to be added to the mixture, so as to avoid the decay of the mechanical properties. In addition,
further experiments must be carried out on concretes, where the presence of gravel leads to improve the stability and mechanical resistance of the
cement matrix
Seismic and Fire Assessment and Upgrading Process for Historical Buildings: The Case Study of Palazzo Colonna in Caggiano
No full textOptimal seismic upgrading of a reinforced concrete school building with metal-based devices using an efficient multi-criteria decision-making method
Full text linkIn the paper, the seismic retrofitting of an existing reinforced concrete school building located in the district of Naples has been examined. The school, which was designed to sustain gravity load only, is composed of seven constructions separated with seismic joints. One of these constructions has been retrofitted with different intervention techniques, namely reinforced concrete walls, steel concentric, eccentric and buckling restrained braces and steel shear panels, whose non-linear behaviour under seismic actions in terms of performance point detection have been evaluated and compared using Capacity Spectrum Method. Finally, the choice of the best intervention technique from economic, structural and environmental point of view has been done utilising an efficient multi-criteria decision-making (MCDM) method, the so-called TOPSIS method. From the performed analyses it was found that buckling restrained
braces provide optimal solution for the seismic upgrading of the examined reinforced concrete school building
Leeb hardness experimental tests on carpentry steels: Surface treatment effect and empirical correlation with strength
No full textStructural Assessment and Upgrading for an Old Building Belonging to an Historical Multi-Sports Center in Naples
Full text linkA significant number of non-ductile existing reinforced concrete frame buildings, built in different seismic regions around the world but without adequate seismic detailing requirements, suffered damages, or collapse after past earthquakes. In fact, these reinforced concrete frame buildings are much more susceptible to high level of damage or to collapse than modern code-conforming frames. A crucial issue in the community of the earthquake engineering is the assessment and the upgrading of these non-ductile reinforced concrete structures. In particular, a careful assessment of the existing buildings is very important in order to understand the failure mechanisms that govern the achievement of predefined limit states or the collapse of the structures. Only after an in depth seismic assessment, the best upgrading/retrofit strategy can be designed and applied to the structure. In some cases, the historical value of these buildings makes the assessment procedure and the upgrading design more complicated due to the constraints related to the limited possibility of interventions. In this work, a building belonging to an old multi-sports center, is used as case study. The complex orbits around the soccer stadium called Collana and located in Naples. This soccer stadium was initially built in the late ‘20s and then it was completely rebuilt in the post-war period and used as a sports center for different sporting activities. Currently, the complex includes a soccer field, an athletic track, three indoor gyms, three tennis fields, a medical center sports, and the indoor pool building investigated herein. The analysis of seismic vulnerability implemented for the case study building shows an unsafe condition under both vertical and seismic loads. The building upgrading is provided choosing the best strategy among different options in order to achieve a certain predefined threshold of the seismic safety for the building. Definitively, the paper presents a real upgrading design case study for a building belonging to an historical complex. Assessment and upgrading are shown based both on linear and dynamic non-linear analyses procedures. Finally, the effectiveness of the structural interventions of upgrading is measured coherently with the new Italian guidelines for seismic risk classification of constructions
Innovative and Traditional Techniques for Seismic Retrofitting of an Existing RC School Building: Life Cycle Assessment and Performance Ranking through MCDM Methods
No full textInfluence of different knowledge levels on the seismic retrofit cost assessment of a RC school building
No full textComparative seismic evaluation between numerical analysis and Italian Guidelines on Cultural Heritage applied to the case study of a masonry building compound
No full textThe general objective of the work is to draw attention to the issue of seismic vulnerability analysis of masonry building compounds, which characterise most of the Italian historic towns. The study is, in particular, based on the analysis of an aggregated construction falling in the town of Arsita (Teramo, Italy) damaged after the 2009 L’Aquila earthquake. A comparison between the seismic verifications carried out by using the 3Muri commercial software and those deriving from the application of the Italian Guidelines on Cultural Heritage has been performed. The comparison has shown that Guidelines provide results on the safe side in predicting the seismic behaviour of the building compound under study. Further analyses should be performed aiming at suggesting some modifications of the simplified calculation method to better interpret the behaviour of building compounds under earthquake
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