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Redaelli Dario

Professeur HES ordinaire

Compétences principales

Professeur HES ordinaire

Téléphone: +41 26 429 66 80

Bureau: HEIA_D40.05

Haute école d'ingénierie et d'architecture de Fribourg
Boulevard de Pérolles 80, 1700 Fribourg, CH

Institut
iTEC - Institut des technologies de l'environnement construit

BSc HES-SO en Génie civil - Haute école d'ingénierie et d'architecture de Fribourg

Construction en béton 2
Construction en béton 3
Construction en béton 4

MSc HES-SO en Engineering - HES-SO Master

Module d'approfondissement par projet - Structures et constructions avancées en béton

En cours

Reuse Living Lab

Rôle: Requérant(e) principal(e)

Financement: Smart Living Lab - SLL

Description du projet :

L’objectif du réemploi est d’utiliser des éléments de construction en les transformant un minimum, afin de réduire la consommation de ressources et d’énergie. Cette approche promeut la durabilité et peut transformer radicalement l’économie de la construction. Le réemploi force à repenser tout le processus de projet, de mise en œuvre et de gestion des bâtiments. Cette réorganisation concerne tous les acteurs de la construction : maitre d’ouvrage, mandataires concepteurs, et entreprises de construction et administrations. Une mise en réseaux et une réflexion commune semblent indispensables pour réussir cette transition vers une économie circulaire. Le projet de création d’un Reuse Living Lab à la HEIA s’inscrit dans cet objectif global et a but pour de favoriser le développement de méthodes et des solutions techniques de réemploi centrée sur les besoins des utilisateurs et portées conjointement par l’ensemble des acteurs (académiques, entreprises, mandataires et administrations).

Equipe de recherche au sein de la HES-SO: Redaelli Dario , Nseir Joanna , Buri Hani , Grandjean Nicolas

Durée du projet: 01.02.2024 - 30.09.2025

Montant global du projet: 155'000 CHF

Statut: En cours

Terminés

NextEarthBuild ' « Une nouvelle génération d'éco-construction en terre d'excavation recyclée »

AGP

Rôle: Requérant(e) principal(e)

Financement: HES-SO Rectorat

Description du projet : Pour rendre possible une densification urbaine durable tout en maintenant une qualité de vie acceptable, il est indispensable de repenser la manière et la matière dont les bâtiments et les aménagements sont conçus et construits. Parmi les déchets de la construction qui ne sont pas valorisés, la terre d'excavation présente le volume le plus important. Ce projet, réalisé en collaboration avec la Haute École d'Ingénierie et de Gestion du canton de Vaud (HEIG-VD), vise à faire de la terre d'excavation une nouvelle matière première qui offre une solution pragmatique et rentable au problème de la construction de bâtiments et des aménagements extérieures, tels que les parkings et les chemins piétons, souvent réalisées en béton ou en mortier silico-calcaire. La terre d'excavation pourrait donc devenir : - le composant incontournable d'une nouvelle technique de construction et de préfabrication appelée shotearth (terre projetée) ; - l'ingrédient qui rend végétalisables et auto-recyclables des nombreux aménagements extérieurs. Ce projet a pour but de développer des nouvelles manières de concevoir et de construire avec la terre d'excavation, grâce à : - l'utilisation de techniques de fabrication innovantes (projection classique, impression 3-D d'élément complexes) ; - l'optimisation des matériaux, alliant performances et éco-compatibilité ; - l'optimisation de la forme et du lien entre forme et fonction.

Equipe de recherche au sein de la HES-SO: Leopold Sebastian , Galé Benjamin Claude , Delaquis Dominique , Redaelli Dario , Lasvaux Sébastien , Murith Noé , Savino Vincenzo , Bourrier Hervé , Schranz Noè , Albertoni Loran , Agustoni Amedeo , Goulouti Kyriaki , Viviani Marco , Frossard Mija

Partenaires académiques: INSIT; IGT; FR - EIA - Institut iTEC; FR - EIA - Institut SeSi

Partenaires professionnels: Pittet

Durée du projet: 01.01.2019 - 30.09.2022

Montant global du projet: 232'000 CHF

Statut: Terminé

Journée BFUP 2015 22 octobre 2015

AGP

Rôle: Requérant(e) principal(e)

Financement: inscriptions; Divers

Description du projet : Suite au succès obtenu lors de la première Journée d'étude sur les Béton Fibrés à Ultra hautes Performances, qui a eu lieu à l'EIA de Fribourg en 2011, une deuxième journée est organisée en Septembre 2015 en collaboration avec l'EPFL et la Haute École Bernoise. Cette journée sera l'occasion de présenter le nouveau cahier technique 2018 de la Société des Ingénieurs et des Architectes (SIA), qui concerne le dimensionnement des structures en Béton Fibré à Ultra Hautes Performances et qui a vu la participation de plusieurs collaborateurs ou anciens collaborateurs de l'EIA-FR (René Suter, Lionel Moreillon, Blaise Fleury).

Equipe de recherche au sein de la HES-SO: Nseir Joanna , Redaelli Dario , Ricci Laurent , Schranz Noè , Muresan Alex-Manuel

Partenaires académiques: FR - EIA - Institut iTEC; EPFL - ENAC - MCS; Berner Fach-Hochschule; Redaelli Dario, FR - EIA - Institut iTEC

Durée du projet: 01.01.2015 - 31.12.2021

Montant global du projet: 92'554 CHF

Statut: Terminé

Build-Unbuild-Repeat : a multi-generation structural system for office buildings

AGP

Rôle: Requérant(e) principal(e)

Financement: FR - EIA - Général école Ra&D; FR - EIA - Institut iTEC; SLL HEIA-FR; EPFL - SXL; FR - EIA - Institut iTEC

Description du projet : The project is the result of a collaboration between Structural Xploration Lab (EPFL, Prof. Corentin Fivet, research leader) and Institute of Environnemental and Construction Technologies (HEIA, Prof. Dario Redaelli). The goal of this research is to develop a structural (i.e. load bearing) system that can be reused over a minimum of three building lifespans. The unusual requirements for such a promising system are threefold: (1) elements must be robust enough to withstand chemical and mechanical attacks over a very long period of time ' e.g. 200 years at almost zero maintenance cost; (2) the system must allow its deconstruction and reconstruction at minimum twice and with minimum transformation costs, meaning that a minimum of material should be replaced or repaired; (3) in case of deconstruction/reconstruction, the modularity of the system will allow to rearrange the geometry of the structural skeleton (spans, position of columns, walls and openings, etc.)

Equipe de recherche au sein de la HES-SO: Redaelli Dario , Zwicky Daia , Rime Alain , Muresan Alex-Manuel

Durée du projet: 01.01.2017 - 31.12.2019

Montant global du projet: 123'015 CHF

Statut: Terminé

2024

RE:SLAB—a load bearing system for open-ended component reuse in building structures

Article scientifique ArODES

Xavier Estrella, Alex Muresan, Jan Brütting, Dario Redaelli, Corentin Fivet

Frontiers in Built Environment, 10, 2024, 1355445

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Résumé:

The construction industry plays a major role in the high levels of greenhouse gas emissions, resource consumption, and waste generation observed nowadays. Key to the circular economy, structural component reuse arises as a promising solution to divert construction waste from landfilling and avoid the production of new components. In this context, this paper presents the conceptual design of a new slab-and-column system called “Re:Slab”, optimized for disassembly and open-ended reassembly over multiple building lifespans. Beyond conventional considerations of modular sizing and reversible connections, the proposed system provides designers with a minimum kit of parts that is capable of exceptionally diverse building layouts–e.g., related to floor geometry, span between supports, applied loads, and spatial transformations. Attention is given to easily operable assembly and disassembly techniques, embodied environmental impacts, and manufacturing costs. As a result, the proposed system reaches unprecedented high levels of versatility, making it capable of adapting to future functional design requirements that are hard to predict over long-term social developments. Options for increased economic viability are identified, which are necessary to promote widespread adoption of the system.

2023

Composite cimentaire fibré ultra-performant :

Livre ArODES

concevoir, dimensionner, construire : 4ème journée d'étude, 26 octobre 2023

Eugen Brühwiler, Cornelius Oesterlee, Dario Redaelli

2023, Biel : Berner Fachhochschule ; Architektur, Holz, Bau ; Institut für Holzbau, Tragwerke und Architektur Fribourg : Haute école d'ingénierie et d'architecture Fribourg, 152 p.

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Résumé:

Les composites cimentaires fibré ultraperformants (CFUP) sont utilisés dans la pratique en Suisse depuis vingt ans. Les applications comprennent avant tout la remise en état et le renforcement d’ouvrages existants en béton armé ou précontraint, où l’utilisation du CFUP permet de concevoir et mettre en œuvre des procédés de construction rationalisés, peu invasifs et économes. En outre, le CFUP est de plus en plus utilisé pour les nouvelles constructions, souvent en combinaison avec le béton, l’acier ou le bois dans des structures mixtes. Cette quatrième journée d’étude a pour but de présenter des projets CFUP marquants réalisés ces dernières années et de partager des expériences concrètes d'élaboration de projets, dimensionnement et exécution. Les projets présentés permettront de démontrer le potentiel d'application de la technologie CFUP, en respectant les principes du développement durable. Les particularités du Cahier Technique SIA 2052 révisé seront également présentées.

2022

Caratterizzazione di due calcestruzzi UHPFRC commerciali :

Article professionnel ArODES

valutazione di proprietà meccaniche e di durabilità

Bianca Paola Maffezzoli, Dario Redaelli, Elena Redaelli

Structural : building engineering + structural design, 242, 2022

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Résumé:

This note presents the results of a research aimed at assessing and comparing the properties of two commercial ultra-high-performance fiber reinforced concretes (UHPRFC) made with the same amount of steel fibers (2.5% vol.). Besides the basic properties at hardened state, such as compressive strength and elastic modulus, durability-related parameters are measured, such as electrical resistivity, resistance to carbonation and chloride penetration, water absorption rate and water absorption. Microstructure is also studied by means of optical and electron microscopy. The results show that, although fibers may locally increase the presence of interfacial voids in the cement paste and decrease the electrical resistitvity of UHPFRC, both products exhibited an overall excellent behavior if compared to ordinary concrete.

2020

Sustainability through reuse :

Article scientifique ArODES

a reconfigurable structural system for residential and office buildings

Alex Muresan, Jan Brütting, Dario Redaelli, Corentin Fivet

IOP Conference Series: Earth and Environmental Science, 2020, vol. 588, article no. 042066

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Résumé:

Current load-bearing systems for buildings rarely have a beneficial end of life. Modular design is a proven solution for revalorizing obsolete structures, but it hardly competes with conventional solutions: the range of future spatial configurations that the modules will accommodate is usually too limited to balance additional upfront costs due to necessary oversized elements and extra connections. Through a review of building demolition cases, this paper first presents motives, challenges and requirements for overcoming adverse end-of-life environmental impacts of building structures. Then a new structural system addressing the specified design constraints is introduced. The system is a highly versatile kit of slab and column elements. Contrary to existing modular solutions, its element dimensions do neither constrain the positioning of columns nor the shape of floor plans. Slab elements are stacked vertically to tune bending and shear stiffnesses locally and ensure serviceability requirements for a wide range of column and load cases layouts. All connections between elements are reversible and ready for reuse. Accordingly, the proposed structural system is well-suited for multiple service cycles and architectural needs, mitigating the detrimental effects that buildings have on the environment.

Structural behavior of prestressed ultra-high performance fibre-reinforced concrete beams with and without openings: comparison between experimental results and finite element modelling techniques

Article scientifique

Redaelli Dario, Nseir Joanna

American Concrete Institute, ACI, 2020 , pp. 474-483

2019

Béton fibré ultra-performant :

Livre ArODES

concevoir, dimensionner, construire : 3ème journée d'étude, 24 octobre 2019

Eugen Brühwiler, Cornelius Osterlee, Dario Redaelli

2019, Biel : Berner Fachhochschule ; Architektur, Holz, Bau ; Institut für Holzbau, Tragwerke und Architektur Fribourg : Haute école d'ingénierie et darchitecture Fribourg, 196 p.

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Résumé:

Le béton fibré ultra-performant (BFUP) est appliqué en Suisse depuis plus de 15 ans pour la remise en état et le renforcement des structures existantes. Il est, également, de plus en plus utilisé dans la nouvelle construction. Avec plus de 100 réalisations achevées, le BFUP se positionne comme nouveau matériau de construction permettant la mise en oeuvre de procédés originaux, peu invasifs et économes. Après les deux premières journées d'étude du 2011 et 2015, la 3ème journée d'étude suisse BFUP présente des méthodes d'ingénierie pour l'élaboration de projets et pour le dimensionnement. Elle promeut le partage d'expériences de réalisation de projets BFUP. Ainsi, les multiples possibilités d'utilisation de la technologie BFUP, l'applicabilité désormais courante de cette technologie sur chantier et les tendances de développement actuelles sont démontrées.

2016

Experimental and numerical study on the use of high-strength and ultra-high-performance fibre-reinforced concrete in columns

Chapitre de livre ArODES

Dario Redaelli, Ana Spasojevic, Aurelio Muttoni

fib Bulletins (pp. 193-202). 2016

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Résumé:

High-strength concrete (HSC) is common.ly used for columns that need to withstand significant compressive forces and bending moments. However, the brittleness that characterized HSC behaviour negatively affects the ultimate strength and ductility of columns. Thanks to fibres, high-strength fibre:-reinforced concrete (HSFRC) and ultra-highperformance fibre-reinforced concrete (UHPFRC) have a rather ductile behaviour in tension and compression and may be used to improve the structural response of highly stressed columns, thus leading to thinner sections and a reduction of ordinary reinforcement. This paper presents the results of a preliminary test campaign on HSFRC and UHPFRC columns under bending with normal force. Several atrrangements of ordinary reinforcement were tested, including columns without any longitudinal or transversal reinforcement. The observed behaviour is interpreted by means of a miechanical model. Based on test results and parametrical analysis, the contribution of fibre:s to the structural response and the possibility to replace ordinary reinforcement with fibres are discussed.

2023

Reuse of concrete for the construction of a retaining wall :

Conférence ArODES

a case study

Agnès Collaud, Marco Mongillo, Elena-Lavinia Niederhäuser, Julien Pathé, Dario Redaelli, Hani Buri

Journal of Physics: Conference Series ; Proceedings of cisbat 2023, the built environment in transititon, Hybrid International Scientific Conference, 13-15 September 2023, Lausanne, Switzerland

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Résumé:

A promising strategy to reduce the environmental impact of the construction industry is the reuse of structural elements resulting from the deconstruction of existing buildings. However, despite a growing interest from the academic and industrial communities, practical examples of the reuse of structural elements remain very scarce at present, especially in the case of reinforced concrete buildings, which generally consist of a monolithic load-bearing skeleton that has not been designed for dismantling or reuse. This paper presents the results of a study on the reuse of concrete blocks from the deconstruction of an existing building as components for the in-situ construction of a new retaining wall. A real case study is considered. It consists of a building constructed in the 1970s. The developer of the new building wishes to reuse parts of the old building to create a new retaining wall on the boundary of the plot, with a length of 105 metres and a variable height between 60 and 250 cm. The dimensions and shape of the concrete blocks can vary considerably depending on the deconstruction technique used. In order to take into account this aspect, as well as the variable height and the mechanical support of the retaining wall, alternative solutions have been analysed. This paper presents the conceptual design and preliminary dimensioning of these solutions, as well as a discussion of their ability to meet all the technical and normative requirements.

A reuse-ready timber slab-and-column system for modular building structures

Conférence ArODES

Xavier Estrella, Alex Muresan, Dario Redaelli, Jan Brütting, Jonas Warmuth, Corentin Fivet

Proceedings of the World Conference on Timber Engineering (WCTE 2023), 19-22 June 2023, Oslo, Norway

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Résumé:

The construction industry is a significant contributor to resource consumption and waste generation. To address this issue, component reuse has been proposed as a way to prevent valuable building elements from being discarded and avoid producing new ones. However, the lack of ciruclar economy principles in existing structures makes it difficult to extract and exploit reusable components fully. This paper presents a new load-bearing timber system (Pixel Slba) designed for disassembling and reassembling multiple times over the building's lifespan. The system goes beyond the traditional concepts of modularity and reversibility, providing designers with a minimum kit of parts that can be used to makle localized adjustements and accomodate a wide range of building designs - such as floor geometry, load conditions, and supports distribution - with little to no new material input. This allows for functional design requirements that are difficult to predict over the long term. The system also focuses on low-tech assembly and disassembly processes, embodied environmental impacts, and manufacturing costs, all of which aim to increase the potential for component reuse. The proposed timber solution proved to be particularly suited to increase the sustainability of short-lived buildings.

2021

Corrosion of reinforcement in UHPFRC :

Conférence ArODES

a preliminary study including the effect of cracking

Bianca Paola Maffezzoli, Dario Redaelli, Elena Redaelli

Proceedings of ICD 2021 Italian Concrete Days, Telematico 14-16 Aprile 2021, Web Conference

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Résumé:

Ultra-High Performance Fibre-Reinforced Concrete (UHPFRC) is characterized by high compressive strength, strain-hardening behaviour in tension and very low porosity. After cracking, crack opening is controlled by the fibres. Therefore, UHPFRC is generally considered as a very durable material and is frequently used in combination with reinforcement for elements exposed to severe environmental conditions. However, scientific evidence on the long-term behaviour of reinforcement embedded in UHPFRC is limited, especially if the simultaneous presence of cracks and chemical attack is considered. This contribution presents the results of a preliminary study carried out to characterize the corrosion behaviour of reinforcement in UHPFRC. Mechanical and durability-related properties of a commercial UHPFRC were determined. Accelerated and long-term corrosion tests were initiated on cracked and uncracked prisms reinforced with carbon or stainless steel rebars.

2020

Structural behavior of prestressed ultra-high performance fibre :

Conférence ArODES

reinforced concrete beams with and without openings: comparison between experimental results and finite element modelling techniques

Dario Redaelli, Joanna Nseir Yared

fib Bulletins : Fibre Reinforced Concrete: From Design to Structural Applications. Proceedings of the ACI-fib-RILEM International Workshop - FRC2018. Technical report

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Résumé:

This paper presents the results of a numerical study carried out by the authors to better understand the structural behavior of prestressed beams with web openings and to identify numerical modelling techniques that allow to adequately predict such behavior. Ultra-High Performance Fibre Reinforced Concrete (UHPC) beams are considered, with a focus on shear-controlled failure modes. For all the beams considered in this study, prestressing is used to resist the main bending moment. However, no other reinforcement is added to the beams, in order to emphasize the structural contribution of the fibers and to focus on solutions that could be economically competitive for the precast industry. The results of non-linear simulations performed with existing finite elements codes are compared and validated against experimental results of tests carried out at the University of Applied Sciences of Western Switzerland. The main assumptions of the numerical simulations are discussed, as well as the results and the limits of the analysis.

2019

Etude expérimentale de l'influence du trafic routier sur l'adhérence BFUP/béton :

Conférence ArODES

concevoir, dimensionner, construire : 3ème journée d'étude, 24 octobre 2019

Dario Redaelli, Blaise Fleury, Daniele Stroligo

Béton fibré ultra-performant : concevoir, dimensionner, construire : 3ème journée d'étude, 24 octobre 2019 ; Ultra-Hochleistungs-Faserbeton : entwerfen, bemessen, bauen : 3. Fachtagung, 24 . Oktober 2019

Lien vers la conférence

Résumé:

L'emploi des Bétons fibrés ultra-performants (BFUP) dans le cadre de réhabilitation ou de renforcement de ponts permet généralement un raccourcissement de la durée du chantier et une limitation de l'entrave au trafic routier. Afin d'exploiter de manière optimale cet avantage, il est cependant nécessaire de définir si une ouverture au trafic à proximité d'une zone de BFUP récemment mis en place risque de péjorer l'adhérence entre le BFUP et le béton ordinaire (BO) de support et de compromettre l'obtention d'un comportement mixte entre ces deux matériaux. Le présent article résume une étude expérimentale, effectuée au laboratoire de structures de la Haute école d'ingénierie et d'architecture de Fribourg (HEIA). L'étude avait pour objectifs de déterminer l'évolution de l'adhérence entre le BFUP et le BO pendant les premières heures qui suivent la mise en place du BFUP, ainsi que les éventuelles conséquences de vibrations ou de sollicitations cycliques, appliquées entre 0 et 48 heures, sur les propriétés d'adhérence à 28 jours.

Innesco e propagazione della corrosione dell'armatura in calcestruzzi fibrorinforzati ad altissime prestazioni (UHPFRC)

Conférence ArODES

Elena Redaelli, Bianca Paola Maffezzoli, Dario Redaelli

Proceedings of GnCorrosione (GnC), 3-5 Iuglio 2019, Palermo, Italy

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Résumé:

This note presents the preliminary results of an experimental investigation aimed at studying the corrosion behaviour of reinforcement in ultra-high performance fibre reinforced concretes. Regarding parameters related with corrosion inititation, tests of capillary absorption, water content and water absorption, electrical restitivity, accelerated carbonation and chloride migration were carried out. Results highlighted that concrete is a very impervious material. Results of corrosion tests - both on carbon steel and stainless steel reinforcements - showed conditions of passivity even after exposure to wetting and drying cycles with chlorides. Only in the presence of cracks, carbon steel reinforcement showed a possible onset of corrosion.

2018

Towards a "comprehensive" and smart platform for coordinated waste management in construction in Geneva? :

Conférence ArODES

a case study

Damien Varesano, Eric Amos, Bernd Domer, Francine Laferrière, Dario Redaelli, Marco Viviani

Proceedings of 20. Status-Seminar "Forschen für den Bau im Kontext von Energie und Umwelt", Zurich, Switzerland, 6-7 September 2018

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Résumé:

In order to reduce environmental and financial costs caused by construction material flow, web platforms have been created. Their objective is to increase the visibility of materials available on construction sites and promote their reuse. A benchmark of existing national and international platforms - considering functional aspects, effectiveness and how the platform interacts with local construction community - has been established by the research team. Strengths and weaknesses of each analyzed platform have been identified, giving an up-todate picture. The benchmark points out, that no “comprehensive“ platform, providing material exchange services as well as support for a large and strong user community, exists. Such a platform could be enhanced by several features – like linking it to geographical information systems and technical assistance, creating a coordinated waste management among construction sites thereby. The Great Geneva Area has been identified as an ideal location to implement the concept and an action plan has been proposed.

Le vivant et le recyclage des matériaux de chantier, facteurs de résilience environnementale et de lien social

Conférence ArODES

Eric Amos, Bernd Domer, Francine Laferrière, Dario Redaelli, Damien Varesano, Marco Viviani

Proceedings of 20. Status-Seminar "Forschen für den Bau im Kontext von Energie und Umwelt", Zurich, Switzerland, 6-7 September 2018

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Résumé:

L’impact sur le plan social, écologique et économique de la construction d’habitats, de bâtiments administratifs et industriels, d’infrastructures de transport et de loisir et leurs aménagements, n’est plus à démontrer. Épuisement des ressources naturelles, transformation des matériaux, transports, gestion des déchets de chantier et d’excavations, autant de sources d’émissions de GES et d’effets négatifs sur le sol et le paysage qui influent sur la qualité de vie et les perspectives d’avenir de la population, à l’échelle du territoire, de la ville, du quartier. Cette présentation aborde la question de la prise en compte du vivant dans une démarche d’optimisation de la qualité de notre environnement, dimension encore trop souvent sous-estimée dans le processus de la construction et véritable enjeu de ce début de 21e siècle. 1. L’impact écologique : tenir compte du sol, non comme un matériau inerte, socle physique aux seules qualités de support, mais comme un complexe vivant de grande valeur et grande fragilité, rare et indispensable à la végétation et à la gestion des eaux. Le sol fertile se raréfie en milieu bâti, dans la ville en particulier où l’anthroposol et les revêtements imperméables deviennent la règle. 2. L’impact social : Mettre en relation les acteurs du site, une responsabilité sociale. La prise en compte des personnes, habitants actuels et futurs, voisins, la population dans son ensemble et les visiteurs, tous impactés de près ou de loin par les nuisances des travaux, la transformation des lieux, la perte d’éléments repères et à la recherche affirmée et croissante d’une qualité de vie en espace construit.

Design space of modular slab systems with discrete stiffness distribution and irregular column layout

Conférence ArODES

Alex Muresan, Jan Brütting, Javier Cañada, Dario Redaelli, Corentin Fivet

Proceedings of the IASS symposium 2018, creativity in structural design, 16-20 July 2018, MIT, Boston, USA

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Résumé:

A known challenge of modular structural systems is to avoid the oversizing of its elements while allowing a wide variety of spatial layouts. Considering any given floor outline and the availability of square slab elements with three discrete bending and shear stiffness, this paper explores: 1) the minimal geometric and topological rules that ensure a positioning of columns satisfying serviceability requirements; and 2) for a given satisfying positioning of columns, the distribution of slab elements that minimizes the overall weight of the system. This study is part of a larger project aimed at developing a highly flexible floor system whose element dimensions do not constrain the positioning of the columns nor the shape of the floor plan. Hence, the structural system could be adapted over time to changing architectural needs.

Structural behavior of prestressed ultra-high performance fibre-reinforced concrete beams with and without openings :

Conférence ArODES

comparison between experimental results and finite element modelling techniques

Dario Redaelli, Joanna Nseir Yared

Proceedings of FRC 2018 - 3rd ACI-fib-RILEM Workshop on fibre reinforced concrete: from design to structural applications, 28-30 June 2018, Desenzano, Lake Garda, Italy

Lien vers la conférence

Résumé:

This paper presents the results of a numerical study carried out by the authors to better understand the structural behavior of prestressed beams with a complex geometry and to identify numerical modelling techniques that allow to adequately predict such behavior. UltraHigh Performance Fibre Reinfored Concrete (UHPC) beams with and without openings are considered, with a focus on shear controlled failure modes. For all the beams considered in this study, prestressing is used to resist the main bending moment. However, no other reinforcement is added to the beams in order to emphasize the structural contribution of the fibers and to focus on solutions that could be economically competitive for the precast industry. The results of non-linear simulations performed with existing finite elements codes are compared and validated against experimental results of tests carried out at the University of Applied Sciences of Western Switzerland. The main assumptions of the numerical simulations are discussed, as well as the results and the limits of the analysis.

2016

Seismic retrofitting of masonry walls with thin UHPFRC layers

Conférence ArODES

Mylène Devaux, Dario Redaelli, Jonathan Moix

Proceedings of Conference: HiPerMat - 4th International Symposium on Ultra-High Performance Concrete and High Performance Construction MaterialsAt, 9-11 Mars 2016, Kassel, Germany

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Résumé:

Brick masonry is one of the most competitive technologies for the construction of walls in residential buildings. However, the structural response of masonry walls under seismic action has major drawbacks: a relatively low resistance to horizontal forces and a limited ductility. Several strengthening techniques already exist for masonry walls, such as the use fiber-reinforced plastics (FRP) systems. However, the effectiveness of these techniques can be limited by structural problems (e.g. debonding), complex in situ application, or their cost. An alternative strengthening technique is currently explored at the School of Engineering and Architecture of Fribourg, namely the application of thin layers of ultra-high performance fiber-reinforced concrete (UHPFRC) to improve the strength and ductility of masonry walls. The experimental results of a first test series on real-scale masonry walls reinforced with different arrangements of UHPFRC layers are presented below.

Réalisations

PEOPLE@HES-SO
Annuaire et Répertoire des compétences

Redaelli Dario

Professeur HES ordinaire

Compétences principales

Ingenierie structurale

Construction en béton armé

Béton fibré ultra-performant

Professeur HES ordinaire

PEOPLE@HES-SO Annuaire et Répertoire des compétences

Redaelli Dario

Professeur HES ordinaire

Compétences principales

Ingenierie structurale

Construction en béton armé

Béton fibré ultra-performant

Professeur HES ordinaire

PEOPLE@HES-SO
Annuaire et Répertoire des compétences