Search results for "Retrofit"
showing 10 items of 132 documents
Approccio “Life Cycle Thinking” applicato alla riparazione di una scuola danneggiata dal terremoto dell’Italia centrale
2017
L’adeguamento sismico ed il miglioramento energetico delle strutture sono diventati al giorno d’oggi una priorità. Buona parte del patrimonio edilizio esistente si trova in stato di grande obsolescenza strutturale, architettonica ed energetica. Oltre alla prevenzione, tuttavia, un aspetto molto importante riguarda la riparazione e riqualificazione degli edifici resi inagibili dagli eventi sismici recentemente accaduti nel territorio nazionale. In modo particolare, nel presente articolo verrà preso in considerazione un edificio del plesso scolastico sito nel Comune di Pievebovigliana, provincia di Macerata, danneggiato dai terremoti che hanno colpito l’Italia centrale il 24.08.2016 e il 30.1…
Excessive Deflection in Long-Span Timber Beams of a Historical Building in the South of Italy: Analysis and Retrofitting Design
2020
AbstractIn 2018, under service conditions, excessive deflections were observed in the long-span timber beams of the first floor of the former Sant’Elisabetta Monastery in Palermo (Italy). The build...
Structural Analysis, Retrofitting Design, and In Situ Control of Permanently Damaged Long-Span Timber Beams of a Historical Building in the South of …
2020
AbstractIn 2018, under service conditions, excessive deflections were observed in the long-span timber beams of the first floor of the former Saint Elisabeth Monastery in Palermo (Italy). The build...
Increasing the shear capacity of reinforced concrete beams using pretensioned stainless steel ribbons
2017
In this work, the second part of an experimental campaign investigating the efficiency of an alternative retrofitting method for increasing the flexural and/or shear capacity in reinforced concrete beams, based on the use of prestressed stainless steel ribbons and steel angles, is presented and analytically reproduced. This group of tests focuses on the ability of the adopted retrofitting method to improve the shear strength and ultimate deformation of reinforced concrete structural elements. As described in a companion paper, the adopted retrofitting method is alternative to traditional techniques of reinforced concrete retrofitting, being easy to install and usually reversible, and charac…
Comparative experimental analysis on the compressive behaviour of masonry columns strengthened by FRP, BFRCM or steel wires
2017
Abstract In the last decade, several studies have investigated the application of Fibre Reinforced Polymer (FRP) wraps to masonry piers in order to provide a confinement effect and enhance compressive strength and ductility. Although this technique has proved to be quite effective, various drawbacks arise when organic resins are used to bind fibres. To solve these problems, different techniques have been developed to be used as alternative methods for enhancing the structural performances of weak masonry columns. Among these, the use of Basalt Fibre Reinforced Cementitious Matrix (BFRCM) wrapping, or the application of steel wires at mortar joints. This paper presents the results of an expe…
Experimental in situ behaviour of unreinforced masonry elements retrofitted by pre-tensioned stainless steel ribbons
2014
Abstract The results of in situ tests carried out on unreinforced and reinforced poor rubble masonry full-scale walls in the earthquake prone Messina (Italy) area are presented and discussed. This experimental research was aimed at the assessment of the in plane shear behaviour of ancient masonry strengthened with an innovative system for masonry and retrofitting of reinforced concrete element constituted by three-dimensional pre-tensioned stainless steel ribbons. A comparison between different strengthening configurations was made in order to characterise the behaviour of masonry panels under shear-compression load, focusing attention on the diagonal cracking failure mode. The effectivenes…
Masonry columns confined with fabric reinforced cementitious matrix (FRCM) systems: A round robin test
2021
Abstract The conservation and the preservation of existing masonry buildings, most of them recognized as cultural heritage, require retrofitting techniques that should reduce the invasiveness and assure reversibility and compatibility with the substrate. In this perspective, the strengthening system should be able to improve the bearing capacity of the structural member and, at the same time, to assure mechanical and material compatibility. The use of Fabric Reinforced Cementitious Matrix (FRCM) composites is now recognized to be suitable for these purposes. Indeed, the inorganic matrix has comparable properties with respect to the existing historical mortars while the fabric has relevant t…
A strategy for the finite element modeling of FRP-confined concrete columns subjected to preload
2018
Abstract Compressive behavior of columns strengthened by means of an outer elastic confinement provided e.g. by fiber-reinforced polymer (FRP) jackets has become a main topic in the field of structural retrofitting. In details, the problem of the response assessment of strengthened columns is still under study. Many analytical formulations have been proposed to describe the compressive behavior of confined concrete under both monotonic and cyclic loads. However, the effect of a stress/strain level in the columns already present prior to apply the confinement has been generally neglected until now, also because of the lack of well defined strategies of modeling. In this frame, here, (1) a FE…
Analytical stress-strain law of FRP confined masonry in compression: Literature review and design provisions
2017
Abstract The use of Fibre Reinforced Polymer (FRP) wraps has become common in practical applications to retrofit existing columns with poor structural features. Wrapping the member with one or more FRP sheets makes it possible to induce confinement action and enhance strength and ductility. This application has been widely studied and adopted in reinforced concrete members for about twenty years, while its suitability to masonry columns and piers has been investigated during the last decade. The results of several studies were summarized in different design expressions for calculating effective confinement pressure, ultimate compressive stress and strain, and the overall trend of the stress…
Lessons Learned on the Tensile and Bond Behavior of Fabric Reinforced Cementitious Matrix (FRCM) Composites
2020
Fabric Reinforced Cementitious Matrix (FRCM) composites represent an effective, compatible and cost-efficient solution for strengthening and retrofitting existing structures. A strong research effort was done to investigate the tensile and bond properties of these materials, as well as the overall behaviour of strengthened members. A Round Robin Test was organized by Rilem TC 250-CSM on 28 FRCM composites comprising basalt, carbon, glass, PBO, aramid and steel textiles, embedded in either cement, lime or geopolymer mortars, to collect an experimental dataset and define test protocols. This paper collects the outcomes of this study to highlight fundamental properties of FRCM and to investiga…