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L’Arquitectura del segle XX és un Patrimoni en risc, sobretot per l’abandó, la degradació, la infravaloració. No obstant això, l’augment de l’interés i l’expansió del Patrimoni ens porta a qüestionar els valors que adquireix fins i tot l’arquitectura més recent, i per tant, la seua eventual necessitat de protecció. És necessari un procés de comprensió i de selecció, basat en criteris compartits per la comunitat més àmplia. Aquest va ser l’objectiu principal de les investigacions nacionals i internacionals ací presentades sobre la producció arquitectònica del segle XX. L’observació de les construccions individuals i dels conjunts urbans, que estan molt prop de nosaltres en el temps, porta a reflexionar sobre els seus significats i valors destacant el problema essencial de situar-los en la història. Com més el patrimoni és el resultat d’episodis recents, més el percebem com inserit en una dimensió de processament, de simultaneïtat d’esdeveniments i accions -quasi com les notícies- que tendeixen a legitimar qualsevol forma de canvi, en una perspectiva lligada a la seua condició contemporània. La investigació ha deixat aflorar la riquesa d’aquesta herència, en significació i valor, centrant l’atenció des de la simple materialitat dels edificis a les possibles maneres i formes de la seua interpretació més total i madura.

Ce travail, initié lors d’un séjour d’étude à l’université de Kyoto et mené entre la France et le Japon, relève de l’histoire de l’architecture moderne. Situé dans l’entre-deux-guerres en Europe, en Amérique du Nord et pour la partie la plus importante, au Japon, il présente une partie de la vie et de l’œuvre de l’architecte-ingénieur américain de culture tchèque Antonin Raymond (1888-1976). L’objectif de ce travail a été de décrypter le processus de conception architecturale par lequel cet a...

Gli edifici del Porto Vecchio sono testimonianza di un’applicazione di caratteri tipologici e costruttivi delle costruzioni portuali e costituiscono una straordinaria testimonianza di sperimentazione di tecnologie costruttive del cemento armato, allora poco più che agli albori, eccezionalmente riscontrabili nello stesso contesto. Questo patrimonio ha comportato la trasformazione di Trieste, in particolare nella seconda metà del XIX secolo in seguito agli sforzi economici e tecnici dell’Impero Asburgico, realizzando un legame che, per quanto forte e tutt’ora perdurante, è stato a più riprese indebolito dagli eventi storici. Leggendo questo patrimonio, è possibile ripercorrere e studiare una fase decisiva della storia della tecnica delle costruzioni, e del cemento armato in particolare, vista l’attività svolta da progettisti pionieristici e da imprese costruttrici che hanno mutuato conoscenze e hanno implementato prove empiriche e modalità di realizzazione dei fabbricati industriali, apportando in situ modifiche e miglioramenti a modelli già sperimentali. Il Porto Vecchio è contesto complesso che, per la natura e l’onerosità dei problemi tecnici affrontati, la dimensione dei lavori eseguiti, i contenuti tecnologici, si configura come la prima grande opera di una Trieste moderna. Il riconoscimento della straordinarietà di queste realizzazioni sperimentali costituisce la premessa insopprimibile a qualsiasi intervento volto alla restituzione del patrimonio alla città, alla sua economia e ad un desiderato livello di operatività. Questa è condizione fondamentale per la preservazione dei suoi valori storici, culturali, architettonici e tecnologici, pur accettandone una transizione verso nuove destinazioni d’uso.

Sin dall’inizio della sua lunga carriera, uno degli elementi chiave nell’opera di Pier Luigi Nervi (1891-1979) è senza dubbio rappresentato dalla sua attività di sperimentazione costruttiva, che lo ha portato a esplorare con spirito audace e innovativo le possibilità costruttive del cemento armato, del quale è unanimemente celebrato come uno degli interpreti più geniali e ammirati del Novecento. All’interno della sua ricchissima ed eclettica produzione, una significativa parte, finora relativamente poco indagata nell’ambito dei prolifici studi nerviani, è legata agli edifici per la produzione industriale: questa tipologia attraversa sin dall’esordio tutta la sua carriera, rappresentando un fil rouge esemplare, nelle varie declinazioni esplorate nel corso dei decenni, dell’evoluzione delle idee, del metodo e della ricerca costruttiva di Nervi.

Louis Kahn’s office began work on the Indian Institute of Management in Ahmedabad, India, and the National Assembly in Dhaka, Bangladesh, in 1962. Rather than the work of a single architect, or even of that architect’s office, these buildings should more properly be credited as well to the many other experts involved in their creation, from the construction force that mastered new ways of laying brick and pouring concrete, to the academics and officials whose demands also shaped their forms. Negotiating the different interests, as well as cultural backgrounds, of these often competing kinds of expertise slowed the completion of both projects but ultimately contributed in powerful ways to their appearance. Das Büro Louis Kahn nahm 1962 die Arbeit am Indischen Institut für Management (Indian Institute of Management) in Ahmedabad, Indien und an der Nationalversammlung in Dhaka, Bangladesch auf. Diese Bauten sollten nicht als Werk eines einzelnen Architekten oder eines Architektenbüros angesprochen werden, sondern auch die zahlreichen anderen an ihrer Entstehung beteiligten Fachkräften honorieren, von den Bauarbeitern, die neue Verfahren des Ziegelmauerns und Betongießens meisterten, bis zu den Akademikern und Beamten, deren Anforderungen ebenfalls die Formen prägten. Die Verhandlung der verschiedenen Interessen und der kulturellen Hintergründe dieser oft miteinander in Konkurrenz stehenden Kompetenzen verzögerte zwar die Fertigstellung beider Bauvorhaben, trug aber letzten Endes wesentlich zu ihrem Erscheinungsbild bei. En 1962, el estudio de arquitectura de Louis Kahn empezó a trabajar en los edificios del Instituto Indio de Administración (Indian Institute of Management) en Ahmedabad, India, y de la Asamblea Nacional de Bangladesh, en Dhaka. El valor de estos edificios no se debe únicamente a que sean la obra de un mismo arquitecto, ni siquiera de un mismo estudio de arquitectos: sería más exacto atribuir el mérito a los numerosos profesionales que contribuyeron a su creación, desde el trabajo de los obreros que dominaron nuevas formas de enladrillar y colar el cemento, hasta el de los académicos y los funcionarios cuyos requisitos también moldearon sus formas. Las negociaciones, superando intereses y culturas diferentes, y a menudo la experiencia antagónica de cada colectivo, ralentizaron la finalización de ambos proyectos, pero en última instancia fueron una poderosa contribución a su aspecto externo. En 1962, le cabinet de Louis Kahn a débuté son travail sur le bâtiment de l’Institut indien de gestion (Indian Institute of Management) à Ahmedabad, en Inde, et sur celui de l'Assemblée nationale à Dhaka, au Bangladesh. Mais plus qu’à un seul architecte, ou même à un cabinet d'architecture, ces bâtiments devraient plutôt être attribués à la fois aux nombreux experts impliqués dans leur réalisation, depuis la main-d’œuvre maîtrisant de nouvelles technique de maçonnerie et de coulage du béton, jusqu’aux universitaires et fonctionnaires dont les exigences se répercutèrent également sur la forme. La négociation des différents intérêts ainsi que les origines culturelles de ces types d’expertise souvent en concurrence entre elles ont ralenti l’aboutissement des deux projets pour finalement contribuer de façon déterminante à leur aspect final. Lo studio di Louis Kahn iniziò a lavorare al progetto dell’Istituto indiano di gestione (Indian Institute of Management) di Ahmedabad, India, e all’Assemblea nazionale di Dacca, Bangladesh, nel 1962. Più che come opera di un solo architetto, o del suo studio, questi edifici dovrebbero piuttosto essere considerati come l’opera collettiva di tutti gli esperti coinvolti nella loro creazione: dalla manodopera che ha saputo padroneggiare nuove tecniche per posare mattoni e colare cemento, agli accademici e ai funzionari le cui richieste hanno contribuito a modellarne le forme. Il fatto di dover far coesistere interessi e background culturali diversi e competenze spesso in contrasto tra loro ha certo rallentato il completamento di entrambi i progetti, ma ha contribuito in modo consistente al loro aspetto finale.

Recently researches, in the field of civil engineering, have been addressed to study high performance concrete materials. In particular Fiber Reinforced Concrete (FRC) materials are very promising. With the addition of fibers into the concrete matrix, a brittle material like concrete can be modified towards a composite material with some ductility properties, able to absorb notable impact energy due to the dynamic or cyclic actions, like the seismic action, in the “during and post” cracking stage. Although, several studies were developed further research is needed to investigate some topics. The present work deals with the study of FRC materials used for structural applications with reference to the material and structural behaviour. Initially, the compressive and the tensile behaviour of the FRC material were analyzed by experimental, theoretical and numerical approaches. Specifically, an experimental investigation and a numerical analysis were carried out with the aim to identify the parameters like fiber types and contents, that are able to improve the performance of FRC material with reference to the structural behaviour. The implications on the use of fibers added into the concrete matrix on the workability at the fresh state and on the toughness at the hardened state were also considered. The aim of the experimental investigation was to analyze and compare the mechanical and the fracture properties of FRC materials by varying some main parameters like matrix compressive strength, fiber types (steel/polypropylene), fiber volume content (Vf) and the length of steel fibers (Lf). Through the numerical analysis it was possible to investigate the influence of high steel fiber content on the tensile post-peak behaviour. The numerical results obtained were compared with the experimental ones and the reliability of the numerical procedure was checked. A comparative study was carried out between experimental and theoretical stress-strain relationships available in literature, with particular reference to compressive behaviour of FRC. The aim was to evaluate the reliability of the proposed models and their range of validity. Several experimental data available in literature were analyzed and collected in a database. The above database was integrated with further experimental results obtained in the Laboratory of the Department of Structural Engineering at the University of Calabria. At the same time, the analytical uniaxial stress-strain relationship available in literature were analyzed and collected. Each theoretical model was critically analyzed and the reliability was checked through a comparison with the experimental curves of the same author and other available in literature. Subsequently, the structural behaviour was studied. With reference to the behaviour of eccentrically loaded FRC columns interaction diagrams axial load (N) – bending moment (M) of the cross section were computed to highlight the role of some main parameters on the strength. The theoretical models proposed in the Italian guideline CNR-DT 204 (2006) and other models available in literature were used in the analysis. The reliability of the theoretical models to describe the real behaviour of fiber reinforced concrete elements was checked through a comparison with some experimental data on steel fiber reinforced concrete columns subjected to eccentric loads available in literature. With reference to a rectangular FRC cross section, symmetrically reinforced, interactions diagrams, using the relationships proposed in the CNR-DT 204 (2006), were computed by varying some parameters like fiber geometrical properties and contents. The aim was to provide interaction diagrams which can be useful to design/check the strength of the concrete members reinforced with fibers and traditional steel reinforcement. Keywords: Experimental investigation; Fiber reinforced concrete; Post-peak behaviour; Eccentric loads; Stress-strain relationships. Dottorato di Ricerca in Ingegneria dei Materiali e delle Strutture, Ciclo XX SSD, a.a. 2007 Università degli Studi della Calabria Dottorato di Ricerca in Ingegneria dei Materiali e delle Strutture, Ciclo XX SSD ICAR/092007

The seismic vulnerability that characterizes the architectural heritage in Italy requires methods applicable at territorial scale, simplified but reliable for a proper risk assessment and a subsequent planning of intervention strategies. For this purpose, in the present work a method for the seismic vulnerability evaluation at territorial scale was developed in order to analyze the buildings built in Italy between 1930 and 1940, belonging to the architectural movement of Italian Rationalism. Starting from the vulnerability method, based on the European Macroseismic Scale (Grunthal, 1998; Giovinazzi and Lagomarsino, 2004), the proposed methodology provides new parameters related to specific vulnerabilities of the Rationalist architectural heritage. The analysis of these buildings, represented by a sample geographically contextualized to Liguria region (Italy), pointed out that the vulnerability is related to two main reasons. The first reason is the formal characteristics, related to the research of lightness, transparency and boldness that characterized the new architectural language which, in those years, was developing in Italy, as in the rest of Europe. At the base of the formal choices is the use of reinforced concrete, a "new" construction technology: if the use of this material was a valuable tool for the formal renovation in architecture, it is true that it is, at the same time, the second cause of the vulnerability that characterizes the buildings belonging to the Italian Rationalism. In fact, it is necessary to take into account that the construction technique was in its "first steps" at the beginning of the last century, and that, therefore, had not yet fully mastered, causing structural problems, in some cases, already from a static point of view. The scores of vulnerability, assigned to the parameters identified, have been calibrated through parametrical sensitivity analysis on a building "prototype", from a real case study, selected as representative of certain recurring characteristics in the sample. The proposed method allows to assess the vulnerability of this cultural heritage, that is higher than the vulnerability that characterized the reinforced concrete existing building with modern design.

Examined the phenomenon of corrosion of reinforcement induced by the metal chlorides in concrete structures exposed to salt spray and the requirements of UNI-EN 206 and "Guidelines of the Ministry of Public Works on structural concrete", the authors analyze the results of an experiment conducted on cubic specimens made with three mix-design: mix 976 with Rck 30/35 and portland cement 42.5 title; mix with Rck 977 25/30 and pozzolanic cement Title 32.5; mix 978 with Rck 30/35 and pozzolanic cement 32.5 title. The experiment was carried out using accelerated aging tests.

Nel 1963 la municipalità di Swindon (Inghilterra) contatta Pier Luigi Nervi per il progetto della nuova tribuna dello stadio per la locale squadra di football. Le richieste riguardano la definizione di una nuova tribuna in sostituzione di quella esistente, con il vincolo di occupare tutto il lato lungo del campo da calcio e prevedere una capienza di circa 6000 posti a sedere e 4000 persone in piedi. Nervi elabora due soluzioni differenti a riprova della continua attenzione verso soluzioni che soddisfino esigenze statiche economiche ed estetiche.

Examined the phenomenon of corrosion of steel reinforcement induced by chlorides in reinforced concrete structures immersed in saline solution and the requirements of UNI-EN 206 and "Guidelines of the Ministry of Public Works on structural concrete," the authors analyze the results of an experiment conducted on cubic specimens made with three mix-design: mix 976 with Rck 28/35 and portland cement 42.5 title; mix 977 with Rck 25/30 and pozzolanic cement 32.5 title ; mix 978 with Rck 28/35 and pozzolanic cement 32.5 title. The experiment was carried out using accelerated aging tests.