ABSTRACTS DEL CONVEGNO INTERNAZIONALE DI SCIENZA E BENI CULTURALI

-anno 2003-

LA REVERSIBILITÀ NEL RESTAURO

Riflessioni, Esperienze, Percorsi di Ricerca

 

Amedeo Bellini

Restauro, conservazione e reversibilità in architettura – brevi note.

n.d.

 

 

Francesco Doglioni, Paola Squassina

Gradi di reversibilità nel restauro strutturale.

This report deals with some conceptual themes concerning reversibility in structural restoration, and aims at a defìnition and a graduation of the different purposes along which the field of consolidation ranges, that is repair, static consolidation, seismic improvement, structural strenghtening. Some cases of intervention with a different character of reversibility are instanced, and a last case in which a steady structural device is removed.

It is worth laying special stress on the importance of an exact documentation of works done, in order to a future removal or integration as well.

Key-word: dissesto, restauro strutturale, reversibilità culturale

 

Stefano Della Torre

Il rispetto dell’esistente e l’irreversibilità dell’azione

The “principle of reversibility” is discussed here. Modern science, however, does not believe in reversibility at all: time is irreversible, all actions are irreversible.  The word “reversibility”, in the matter of fact, is given different meanings in the various fields of conservation. Often it is not else that avoiding to touch the fabric of buildings. That’s why it would be better not to speak or reversibility any longer, undestanding that, in a vision of Conservation as a process, the core of ethics is the attention for the long-term outcome of any intervention. So the most fitting name of that principle could be “principle of responsibility”.

KEY-WORDS Reversibility, Responsibility.

 

Anna Maria Oteri

La reversibilità nel restauro archeologico : riflessioni su alcuni esempi di Sicilia e Magna Grecia.

This essay proposes some reflections about reversibility in conservation of archaeological sites. Moving by some examples about archaeological sites  in Sicily and Magna Grecia, it proposes two different aspects which concerns the relation between reversibility and ruins. From one hand we include all those aspects strictly connected with technique. These aspects, in outline, follow the most adjourned theoretical matters dealing with the concept of authenticity. They foresee interventions that could be partially removable. This idea, as the following examples show, is well known from archaeologists and architects, but it is not always applied. On the other hand we underline another level of reversibility. It is a theoretical concept rather than a technical one. It deals with reversibility (or non-reversibility)  of all those  interventions, such as anastylosis or  reconstructions, that aim at the realization of a “new past”. In this case we deal with a theme that seems to be ignored by culture of conservation even if it proposes the significant (and maybe irresolvable) conflict between reversibility and need of completeness.

KEY-WORD: Archaeological site, Time, Authenticity, Reversibility, Non-reversibility, Completeness, Perception.

 

 Carmelo Majorana, Giovanna Giugni

Riflessioni teoriche sul concetto di reversibilità.

Two different complementary aspects are afforded in this paper, about reversibility’s concept in Restoration: a restoration theoretical approach and a material behaviour within a structural framework. The first one stems from some basic sources of main authors in Restoration’s Architectural History with the objective of pointing out their own theoretical reversibility’s ideas.

The second one is devoted to the thermodynamic and mechanical aspects of reversibility’s concept in structures made by brickwork, stones and wood based material of Monumental Restoration.

Conclusion are traced regarding reversibility on the light of up-to-date material behaviour and historical Restoration theoretical approaches.

Key – words: Restoration, Architectural History; reversibility. Porous materials. Thermodynamic, anelastic properties.

 

Giorgio Giallocosta, Simona G. Lanza, Michela Ravera

Reversibilità e memoria: immanenza dei limiti e coerenza degli obiettivi.

The philosophic, theoretical and phenomenological aspects of the concept of reversibility can not ignore the following evident dichotomy: the consequences of any operational action interfering with the status quo of the built architecture, although bearing conflicting objectives, anyway reveal some characteristics of irreversibility. In this sense, a transposition in operational terms of the theoretical propositions of reversibility in restoration (or rehabilitation) can only be realized in the form of a tendency, and its effects can be validated in relation with the minimization of the same irreversibility characteristics that are in any case involved.

Also, the maintenance of the values and memories of the existing heritage can not leave apart the above operational interferences, these being the carriers of irreversible transformations (although aimed at contrasting objectives). However the maintenance of such values and memories, in any case worth being addressed, involves not only the material but also the immaterial components of architecture (spaces, distributive solutions, etc.), both of them depositary of the former ones. Past living cultures, ways of using spaces, ambients, etc, are indeed documental values worth being preserved as well, avoiding unacceptable concealments and minimizing operational irreversible actions that can not be eluded (at least in terms, as far as possible, of suitable reading and explaining facilitations).

KEY-WORD    Reversibility, Memory, Immateriality

 

Barbara Vinardi

Reversibilità delle opere di consolidamento tradizionali.

Works of traditional static consolidation produced by restoration culture were specific to confer stability on building, increasing the compression strengths resistance, making the structure compact and opposing the forming of instability through traction resistance elements, through stirrups, chains, braces, spurs, buttresses, rampant arches, pinnacles, framework of wooden beams and substitution of their heads, under-masonry, under-foundations, etc.

It’s a largely question of evident interventions that, from a point of view, compromised the image of the building but, from another point of view, they didn’t altered the static behavior of the structure, preserving the matter.

Manuals of traditional construction and the attitude of some restorers of the past show how, sometimes, it’s better an evident addition, but easily removable and therefore reversible, than a dissimulated intervention, but more substantial respect the physical texture of the object (for instance through restorations with reinforced concrete).

KEY-WORD

Reversibility, traditional consolidations, visibility, to dismantle, compatibility, neutrality, durability.

 

Ciro Piccioli , Carolina Scavone, Valentina Piccioli

. Aspetti scientifici della reversibilità e della complessità nel percorso di restauro: orizzonti di ricerca

The irreversibility of the degradation processes is an existential data of the Cultural property that the attached know very well because is strictly connected to the spontaneous evolution of the systems, in our case the cultural heritage and its environment.  The reasons behind the introduction of the concept of reversibility go back to the beginning of the century and are political and philosophical reasons, as Cesar Brandi expressed in his unexcelled job.

Those reasons find their origin  the conjuncture between positivism, historical materialism, material culture and awareness of the great value of the cultural heritage.  Chemistry, as a science of the trans   formation, is the product of the rise of the positivism within the western modern society  and it becomes the guarantor of the application of the concept of reversibility in the protection of the cultural heritage;  chemistry but not  the chemical one. 

The praxis of the restoration doesn’t refuse the principle, but find it hard to apply;  it happens also especially because the praxis refuse the social control, so we assist  in the practice to an operational limit of the guarantee.  The concept of reversibility, in the confused and conflicting scene of behaviours of  conservation and restoration, keeps its power of organizing the collectives behaviours in matter of protection of the cultural heritage. The legislation  in matter of protection of the Cultural Goods exalts three aspects:  valorisation, protection, and fruition.

Three necessary and conflicting concepts that are the new frontiers of the reversibility in the conservation of the cultural heritage. 

The positivism, in the thought of  Comte,  identifies the human science as the last aim of all other experimental sciences. The empiricist face of the positivism, due to the tumultuous development of natural sciences at the end of the XIX sec and due to a connected development of the technology, gave to sciences an eminently practical aim.

Key word: Reversibility, Chemistry, complexity, restoring, positivism, empirism

 

Franca Maselli Scotti, Annalisa De Comelli, Fabiana Pieri

. Il restauro dei siti archeologici urbani: un percorso di ricerca

The archaeological excavations carried out within the largest project of urban retrieval in an area in the historical centre of Trieste, led to a few problems regarding the use and fruition of the cultural goods and their conservation in the light of different restoration approaches matured within these last years.

In particular we will suggest the case of a section of a Roman road and its connecting structures near the Roman arch called the “Arco di Riccardo”. Reversibility was the concept at the base of the choice, not only of the materials and the products for the surface’s consolidation and protection, but also of the architectural solutions that allow to visit the site.

Choosing to privilege “reversibility”, we thought about the problem of the restoration’s “durability”, above all in relation to the maintenance of cultural goods. The vulnerability of the goods exclusively regards, in fact, the territory concerning the archaeological site and is influenced, furthermore, by natural factors, as well as by factors of anthropical nature, such as the maintenance of the site.

KEY WORDS: Reversibility – durability – maintenance- urban archaeological area

 

Paola Raffaella David

Il criterio della reversibilità è applicabile al restauro? 

What does reversibility mean in restoration field? And again, can reversibility be found in every kind of restoration work?

Should be admitted that the word, as scientific terminology, is only a theorethical abstraction not applyable to restoration? or is it possible to get it in a different meaning, less scientific but more flexible for different fields of intervention?

Cases on surfaces and structure restoration.

KEY WORDS: reversibility, scientific terminology

 

Stefano Gizzi

La reversibilità negli interventi sulle architetture allo stato di rudere

Nd

Luciano Re

Identità e reversibilità dell’immagine urbana

The essay proposes as a necessary ground of cities and landscapes preservation the safeguard of memories of the historical relationships between their manifold architectural and landscape components, such as its result from complex historical processes. Reversibility appears in those fields impossible to be proposed; and for such reason the essay sustains the aim of a careful and aware integration Preservation/Design, conscious of the different times of physical and functional obsolescence of the parts and functions, as well as the opportunity of a design or restoration approach, that does not force itself “over”, but it’s able to preserve both meanings and materials.

KEY-WORD Architecture, Cities, Landscape, Reversibility

 

B. Paolo Torsello

Reversibilità/irreversibilità nel restauro

La dicotomia reversibilità/irreversibilità è un problema centrale della riflessione scientifica, sul quale non si sono ancora raggiunte conclusioni definitive e indiscusse. Perfino il senso comune vorrebbe liberarsi dai vincoli spazio-temporali, aspirando a sottrarsi alla ineluttabilità delle leggi di natura. Ne sono testimonianza i miti, le leggende e il mondo delle fiabe, così come il romanzo, il teatro e il racconto storico. A partire dall'Umanesimo, anzi, la nuova idea di storia configura una sorta di plausibile viaggio nel passato, una possibilità di ripercorrere il tempo a ritroso, sia pure nel senso dell'immaginario. La potenza evocativa del lavoro storico viene, nel campo del restauro, trasferita alla materialità della fabbrica (dell'oggetto restaurato) in un'attività che punta ad attualizzare fasi costruttive del passato, a riguadagnare l'originario, a restituire le radici dell'opera. In tale prospettiva, anche la ricerca della reversibilità negli interventi operati dal restauratore trascende la semplice portata chimico-fisica dei processi e si collega, di fatto, al contenuto formale dell'opera, ad una reversibilità che punta a riguadagnare, attraverso la materia, i possibili valori culturali minacciati da eventi e da interventi nocivi.

 

Serena Pesenti

La reversibilita’ nell’evoluzione disciplinare del restauro

In the history of restoration, the concept of reversibility – and its evolution –is strictly related with the philosophical concept of time. This critical essay deals with this headway, focalizing its main connections.

Key-words: Reversibility, concept of the time,  history and theory of restoration, project of restoration

 

Joan Casadevall Serra

La reversibilità e la compatibilità dei prodotti industriali sugli intonaci tradizionali

Unfortunately, recent façade restoration in our urban old quarters has been more strongly determined by financial or scenery reasons rather than by social or heritage ones. Such situation is shaping an urban landscape more and more dominated by artificial commercial products, imposed on traditional techniques. Is it possible to find a reversible process that does not harm ancient stucco?. We all have witnessed the technical and aesthetic damage synthetic products from the petrochemical industry do to historic buildings. We have replaced empirical artisan knowledge with increasingly sophisticated and costly magistral formulas and instruments. Nowadays, whereas all industrial products are supposed to be officially approved, certified and warranted, we do not yet know how to classify manual processes or how to evaluate the compatibility between recent and traditional materials. These are some of the reasons why we attempt to establish a methodology of non-destructive trials, which will allow us to guess with some independence and precision, what actually happens when a lime whitewash is repainted, how the morphology of its surface changes or what different reactions involve whether an protective is dissolved or emulsified.

Key-word: Reversibility; Façade restoration; Stucco; Compatibility; Industrial products.

 

Alberto Lionello

La reversibilita’ nei sistemi di marginamento della laguna di venezia

The natural systems formed by living organisms continuously change and this is particularly true for the lagoon environments formed by a complex microhabitat; the “Area Plan for the Lagoon of Venice”, in order to safeguard its peculiarities, prescribes that any intervention inside the lagoon area must be reversible. It was tried to face the problem of the erosion of the sandbanks’ borders by using wooden fencings that, sometimes, because of an early deterioration, have proved to be ineffective. For this reason, it is now testing new techniques of bordering based on the use of modular structures realised with geo-meshes of different degrees of strength and degradation, filled with heterogeneous materials with different effectiveness in adsorbing waves-motion. These modular structures, when formed by natural materials only, tend to deteriorate naturally and can become again part of the system itself; on the contrary, if the structures are formed by natural elements mixed together with synthetic products,  it is necessary to put particular care in the project in order to guarantee the complete reversibility.

Key-word: lagoon, sandbanks, borders, geo-meshes, reversibility, renaturalization.

 

Alberto Arenghi, Stefano Della Torre, Gian Paolo Treccani

Reversibilità e fruibilità dell’architettura: il tema delle barriere architettoniche

The theme of accessibility and reversibility is faced referring to the indications given by the Italian law and to the meaning of reversibility when the conservation project and the use of the historic building is considered according to the principles of the 'Inclusive Design'. Actually the Italian law suggests to adopt provvisional and removable solutions when architectural barriers are to be eliminated and this indication can be understood to carry out accessibility through reversible solutions. Since the intervention to eliminate architectural barriers should be characterized by functionality, durability and composing quality, reversibility cannot be accetable and should be neglected and replaced by responsability. Some significative examples are shown

KEY-WORDS: Accessibility, Reversibility, “Inclusive Design”, Architectural Barriers

 

Francesca Albani, Matteo Albasi, Elena Boldetti, Francesco Bonacci, Alessandra Oppio

Reversibilità e compatibilità dell’impiantistica nel progetto di conservazione

The reuse of historic buildings is important for their conservation. Compatibility between  destination and morphology of a building is very complex. Different aspects must be considerated in the design of the system: life-safety, comfort, flexibility, easy maintenance,  conservation of buildings. Health and safety standards in an old building are not the same used in a new one. The reuse of interstitial areas and of external systems is good for conservation of materials in historic buildings and allow reversibility.

A few examples show the way the installation of new systems in an old building could have a high level of reversibility.

KEY-WORD: reversibility, compatibility, reuse, systems, conservation, restoration

 

Daniela Bosia

Tecnologia e progetto per la reversibilita’

Reversible, compatible, durable, acceptable … these are just a few of the adjectives that, for better or worse, have defined – at least in the intentions - many of the reclamation and renovation interventions done on historic buildings in the recent years. However, little notice has been given to the effective outcome of this ostensible reversibility, compatibility, durability, and whatever else, nor does it seem possible to set up an objective framework for these evaluations.  Several injudicious or even slipshod interventions allow us to make some considerations as regards the issue of reversibility. The general concept lends itself to broad and complex interpretations but perhaps, it can be interpreted as regard for and deference to the past, present and future of a building, to those who have commissioned and built it, and to those who use it today or will have to use it in the future. Today, as the field of application of renovation in the construction industry seems to be expanding to embrace the more marginal areas of interest without excessively altering the traditional investigative and operating tools, we might well ask what is necessary to achieve reversibility in a "renovation" intervention. In our analysis into several recent interventions, we intend to investigate more extensively the concepts discussed here. The objective is to substantiate the theory whereby the reversibility of an intervention must or can be determined by a design approach that considers the past, present and future of the building undergoing the intervention and not only the technical aspects in question.

KEY-WORD: Reversibility – Design – Technology – Building

 

Salvatore D'Agostino, Mariangela Bellomo

Il concetto di reversibilita’ nel restauro costruttivo. Riflessioni ed esperienze

Some observations are made concerning constructive restoration and the problem of establishing a chronology for successive interventions. The concept of reversibility in conservation is formulated on the basis of the integrity of the monument and the reversibility of interventions. The criteria established for ensuring sufficient integrity and reversibility are then applied to various cases of constructive restoration, ranging from the temples at Paestum to Castello Caetani in Rome and the complex of Citroniera - Scuderia della Reggia Sabauda di Venaria Reale.

Key-Word: Historical Heritage, Conservation, Reversibility

 

Stefania Cancellieri, Fabrizio De Cesaris

Alcuni aspetti della reversibilità nel restauro dei beni architettonici

The concept of reversibility, to the first analysis, could seem convergent and parallel with the concept of the material compatibility, in that it is respectful and not invasive. However, to a more careful analysis, it is revealed quite in contrast to it if the formal aspect is taken in consideration.

The present contribution illustrates various participations, with strong structural valence, in which they are evidenced distinguished modality of interpretation of the concept of reversibility in connection with the various contexts.

The operating choices must, in fact, to take into consideration more than abstract reversibility, unattainable or often harmful figuratively, also of other valences that carry to specify and better to characterize a practicable and finalized reversibility to the protection of the valuable aspects of the work, critically characterizes in one scale to you of peculiar and meaningful priorities of the specific case.

The examination of these cases, heterogenous and particular, wants to evidence the variety of the aspects with which, in the yard of architectonic restoration, the reversibility concept brings up-to-date. A side that it prevents to define an apodictic and ideological attitude and that it imposes, to every occasion, a critical appraisal of the values in game.

Keywords: reversibility, compatibility, invading, consolidation.

 

Enrico Guglielmo, Edoardo Cosenza

Un esempio di miglioramento sismico reversibile: il caso del campanile della chiesa di s. Lucia, serra san quirico -marche

Masonry ancient buildings are relevant part of Italian cultural and architectural heritage. After the recent 1997 Umbria-Marche earthquake many historically and architecturally important buildings experienced wide damages and losses. Due to recent architectural restoration guidelines any developed intervention must do not change appearance, and must be invasively limited. These principles, that are quite obvious from a cultural and artistic point of view, are very restrictive constraints to engineers design. Furthermore, traditional structural materials may be not suitable for these purposes. Besides, innovative materials as composites may be helpful in matching discussed requirements. This philosophy was applied to the design process of the seismic retrofitting intervention for the bell tower of Serra S. Quirico (Ancona - Italy). A light Carbon-FRP ties system have been chemically gripped on the surface of inner walls. The FRP installation process was planned to avoid any material removal and also to keep any non-structural element have been as it was. The paper describes on site dynamic preliminary tests, intervention principles, design and construction processes for an important masonry bell tower. Experimental tests that prove the reversibility of the system are also showed.

KEY-WORD Bell-tower, seismic retrofit, composites, reversibility, dynamic identification

 

Carla Bortolozzi, Giulia Carpignano, Fabio Fratini, Antonio Rava

Borgo e Rocca medievali a Torino: riflessioni e esperienze intorno al tema della reversibilità.

The “Medieval Borgo and Rocca” was built on the banks of river Po in Turin in 1882-84, by a group of artists and intellectuals assembled in an Art Committee led by Alfredo d’Andrade. The project was executed as a model of medieval architectures.

The restoration processes implemented from time to time at the Borgo have been inspired by changing theories and varying interpretations of the idea of restoration itself. This study exemplifies some cases for which the concept of “reversibility” of the intervention can be applied.

In particular, we illustrate instances of frescos repairing and new analysis of artificial stone.

In many cases this consist of restoration of a previous restoration, to recover the omogeneous aspect of  surface repainted by 1960-‘70 intervenctions, allowed by reversibility of acrilic sinthetic resins and made possible from the original sound fresco tecnique.

KEY-WORD: Restoration,  medieval castle, Turin’s Borgo Medievale, reversibility, preservation, fresco reparing, artificial stone

 

Ingo Müller, André Musolff, Nicola Santopuoli, Leonardo Seccia

Shape memory alloys for the conservation of cultural heritage: new applications also for a real reversibility in the restoration operation.

First results are described of a research project that aims at realizing new types of anchorages and dowels with shape memory alloys. These are applied in the field of restoration of art works such as mosaics, frescoes and statues. Two prototypes are described of which one is minimally invasive and the other one is reversible.

Key-words: shape memory alloys, parietal mosaics, statues, conservation, restoration, reversibility

 

Silvia Vicini, Elisabetta Princi, Simona Gattorno, Benedetta Massa, Enrico Pedemonte

Pietra di Finale: caratterizzazione petrografia e problemi di reversibilità nel consolidamento mediante polimerizzazione in situ.

In this work, the properties of some polymeric materials used as consolidating and protective products in the restoration field of stone manufactured objects, are discussed. The penetration of polymeric consolidating products is very small because of their macromolecular nature and in situ polymerisation of the monomers is suggested as alternative technique to the use of macromolecular solutions. The removal of  polymeric materials on Finale stone has been studied in order to better understand the reversibility of treatments.

The different types of Finale stone are geologically characterised by means microscopy analysis and porosity measurements. The effects of Finale stone porosity on the efficacy of treatment are studied.

Key-words: stone porosity, in situ polymerisation, acrylic polymers, stone protection, reversibility.

 

C. Atzeni, A. Farci, D. Floris, L. Massidda, P. Meloni, U. Sanna

Verifica della reversibilità di stuccature utilizzate nella conservazione di strutture ciclopiche  (Nuraghe Genna Maria, Sardegna).

Conservative interventions on ruins exposed to weathering are particularly difficult and need rigorous criterion of effective reversibility. This paper refers on problems encountered in defining conservative interventions on nuragic monument of Genna Maria in Sardinia.

Among different potential solutions experimented, a particular earth-based mortar was adopted for sealing spaces among stone blocks and so impede access into the structure of meteoric water. After seven years since such conservative intervention, the possibility of removing the mortar without any damage of  stone blocks in contact was verified so demonstrating its effective reversibility.

KEY-WORDS: Sardinia, Nuraghe, Ruins, Weathering, Conservation, Stabilized earth, Reversibility.

 

Gianni Vittorio Galliani*, Giulia Beltrami**, Federica Ciribì

Gli interventi sugli organismi edilizi. Reversibilità tra modifiche e mutazioni

Buildings are complex systems, that we can call built or architectural organisms, according to their proneness to join or not. It’s a biological, not a mechanical reality, that expresses the capability of living together with their inhabitants, of renewing and modifying themself with people needs. Today, the postindustrial reality is characterized by the employment of steel and reinforced concrete and it applies industrial methodologies to objects realized through the preindustrial logic: skeletons in front of dermaskeletons; the first are realized in the postindustrial age, with concrete load-bearing bone structure and the second are realized during the ancient regime, with a structural system made of supporting septums in brick and stone. We need a profound knowledge of these pre and post industrial materials and technologies, but we also need to analyse the genetical code of the ancient buildings, to intervene with correct actions. An ancient construction can be interpreted as a DNA holder, on which depends the structural logic of the building itself. This structural conception must be respected during restorings, because this is the only way to make a reversible action on the building. If the restoring happened in contrast with the building genetical code, due to the natural evolution of the building, a genetical mutation would take place and the ancient organism, transformed in a mutant, would lose its ancient performances, in an irreversible way, without acquiring the new requisites. 

Keywords: Building organism, structural conception, reversibility, statical restoring, urban planning, genoese roofs

 

Gabriella Caterina, Vittorio Fiore, Paola De Joanna Maria Cristina Forlani, Francesca Castagneto

Flessibilità e reversibilità nel progetto di spazi polifunzionali in preesistenze storiche: riflessioni per il progetto di riuso di Palazzo Cicada in Atri

The TERCAS Architecture Prize in 2002 was promoted to develop rehabilitation projects for Palazzo Cicada in Atri (I).

First nucleus of this building was realised in XIV century and later it was enlarged with the St. Andrea’s Church and the Franciscan Monastery. It was used with various function until 1970, when it was closed.

On the same site it was recently discovered an ancient roman theatre; half part of it is located under the building and the other one was excavated and it is now visible.

This Prize constituted an opportunity to analyse the rehabilitation possibility of an ancient building in order to follow both conservation request and new scenarios of use. The function for this building were defined in the announcement: auditorium, library and theatre.

This contribute is aimed to describe how the proposed project realises the integration between the primary structure and new function by employing flexible and polyvalent equipment. The main objective was to minimise transformations while giving a structure with different possible scenarios.

KEY-WORD: conservazione; fruizione; identità; reversibilità; trasformazioni; flessibilità.

 

Lorenzo Jurina

La possibilita’ dell’ approccio reversibile negli interventi di consolidamento strutturale (ovvero un inno al tirante e al puntone

The use of technologically advanced struts and ties often represents an interesting application, or at least an approach, of the criterion of reversibility in structural consolidation of monuments. External and active, these elements are visible and self-explaining, related to modern materials, as they are, with no mimetic intentions and apt to permit a re-intervention on the building, if necessary or convenient.

Some examples of conservative consolidation design are presented, where old and new materials and elements really work together, with reversibility in mind, to preserve the testimony of the past.

Key-words Restoration, structural consolidation, reversibility, strut, tie, design.

 

A. Calia, M. Lettieri,  M. Masieri , G. Quarta

La reversibilità dei trattamenti conservativi: problemi di controllo in sito e in laboratorio

Verifying the reversibility of conservation treatments has proved problematic due to the difficulty of obtaining experimental evidence both in situ and in the laboratory which confirms the effective removal of the product from the stone. In relation to this problem, we present the preliminary results of an experimental study on the reversibility of a treatment performed with an aggregating–protective product belonging to the class of fluorinated copolymers, on two calcarenitic materials, Carparo and Pietra Leccese. These are both highly porous materials but differ in their porosity structure; they are widely used as construction materials in Southern Puglia (the Salento peninsular).

The study was carried out on experimental walls placed outdoors, comparing certain parameters of the stone materials before treatment, after treatment and after the removal of the product. The removal was carried out with poultices of absorbent material impregnated with acetone, recommended by the manufacturer as being a suitable solvent. The reversibility of the treatment applied was verified via low pressure water absorption tests performed in situ and in the laboratory, with capillary tests on cores of material taken from the walls, FT-IR analyses, SEM observations and EDAX microanalysis.

From the results obtained it emerged that the above-mentioned methodologies were able to show that in the case of pietra leccese, the removal of the product was almost totally successful. Some of the tests proved to be inapplicable to a material such as Carparo, while others not only showed that the product had not been removed, but suggested that it had been redistributed over the surface.

KEY-WORDS: conservation, water repellent product, calcarenitic stones, reversibility, control tests.

 

Oscar Chiantore, Salvatore Coluccia, Marco Nicola, Admir Masic

La reversibilità nel consolidamento dei materiali lapidei: studio dell’intervento eseguito nel 1983 sulla statua della “Madonna della Consolata” di Torino.

In 1983 the Carrara marble statue of “Madonna Della Consolata” of Turin was subjected to a consolidation treatment with Paraloid B72 (an ethyl metacrylate-methyl acrylate copolymer) using a vacuum impregnation technique. In 1991 a visual check-up showed the good state of conservation of the statue. Twenty years after the treatment, in collaboration with  Comune di Torino and “Nicola Restauri srl” laboratories a thorough investigation of conservation conditions has been undertaken. The examination has been extended not only to visual characteristics but also to the consolidation conditions of stone material, the level of penetration, and the state of the acrylic consolidant in respect of ageing and reversibility. Polymer modifications at molecular level were studied using spectroscopic, chromatographic and magnetic resonance imaging techniques. Results from samples of the statue are compared with those obtained in laboratory.

Key-Words: consolidation, vacuum impregnation, marble, acrylic resins, magnetic resonance imaging, monitoring, ageing

 

P. Maravelaki-Kalaitzaki, N. Kallithrakas-Kontos

Barium hydroxide as strengthening agent for porous limestones: assessment of efficiency after fifteen years of treatment

The Cathedral of Chania, Crete, Greece, one of the most famous neoclassical religious buildings was built in 1864. It has been subjected to conservative intervention by spraying barium hydroxide in 1988. In the present paper the presence of barium compounds was assessed, given that these compounds are irreversible. The stone material showed degradation phenomena such as: erosion, pulverization, exfoliation and alveolar disease. Analytical data acquired through Fourier Transformed Infrared Spectroscopy (FTIR), X-Ray Diffraction (XRD) and Energy Dispersive X-ray Fluorescence (EDXRF), allowed the comparison of the condition of stone before and after treatment. Pore size distribution, as revealed by mercury porosimeter, remains almost invariable after treatment and natural ageing. Barium was detected on the surface of treated stones only by means of EDXRF, whereas FTIR and XRD show no signs of barium compounds. EDXRF analysis reveals that barium is sporadically present on the treated surface with a depth distribution of up to 2 mm. Therefore, this irreversible treatment was judged not satisfactory and its inefficiency is due both to the application mode and the microstructural characteristics of the stone. A discussion on the replacement of the requirement reversibility with compatibility and retreatability is presented herein.

KEYWORDS: Barium hydroxide, stone, EDXRF, penetration depth, reversibility, compatibility

 

MariaRita Pinto, Stefania De Medici, Katia Fabbricatti

Nuovi usi per edifici esistenti e reversibilità degli interventi

NEW USES FOR EXISTING BUILDINGS AND REVERSIBILITY CONDITIONS

The aim of the intervention on the built heritage is to extend the building’s life-cycle, preserving, the matter and its cultural/historical role. To pursue this objective, the adaptive-use (input of new functions) represents a strategic element to assure continuous management and maintenance of the buildings by the users themselves. However, the input of incompatible uses has, always, involved alterations of the spatial configuration of the pre-existence, by highly transformative interventions that have produced, moreover, considerable loss of matter. The choice of  new functions must be made, therefore, after a preventive evaluation of compatibility.

This paper explains the function of constructive knowledge in the analysis and evaluation on existing buildings, focusing on the physical status and promoting investigations to recognize its technological features and the bonds that have to be respected. The studied cases underline a continous research of technological solutions that aim to guarantee the new function’s settling in reversibility conditions of the intervention.

Key-words: technological features, new uses, technological solutions, reversibility conditions

Giorgio Serafini

La reversibilità nel rinforzo di strutture lignee con interventi estradossali

n.d.

Lucina Napoleone

Inversione temporale e azioni provvisorie. Due modi della reversibilità.

Nell'ambito del dibattito sul restauro architettonico è possibile imbattersi nel termine reversibilità usato secondo accezioni differenti: la prima fa riferimento a una tecnica o a un prodotto che ha la proprietà di essere rimosso in qualunque momento, la seconda alla possibilità di attuare un'inversione temporale, una sorta di riparazione ai guasti dell'uomo e del tempo per ristabilire una configurazione dell'edificio che si pensa sia quella "del pristino splendore". Il saggio sviluppa questi argomenti avendo come filo conduttore da una lato la teoria di Cesare Brandi e i fraintendimenti operati da coloro che, spesso strumentalmente, ad essa si rifanno e dall'altro riflettendo sulla reversibilità come sospensione, come possibilità di operare per azioni provvisorie. KEY-WORDS: time, Brandi, suspension, temporariness

 

Gian Luigi Nicola

Restauro di opere restaurate: problematiche d’intervento in due casi limite.

Over 35 years of working experience as a restorer I have had the possibility and necessity to intervene on artworks already subjected to previous restorations.  Amongst the many experiences it could be relevant to report two significant cases that have allowed to evaluate the level of reversibility of materials most frequently used in the past and sometimes still in use. The first example concerns with the restoration process of a painted mud surface (wall decorations of the cenotaph of Alexander the Great at Kom Madi) treated ten years before with high concentration of Paraloid B72 and kept in unfavourable  conditions (high temperature and low humidity).  The second example instead concerns with damages due to a layer of silicatic product applied at the beginning of the XX century on an Egyptian sarcophagus made of stucco wood and painted. In both cases it has been necessary to intervene again on material not artificially deteriorated.

Key-Words: Egypt’s Cultural Heritage, conservation, restoration, Alexander The Great, reversibility, sarcophagi

 

Vincenzo Borasi, Paolo Piantanida

È culturalmente irrinunciabile il requisito della rever-sibilità nei progetti di recupero funzionale di strutture antiche autentiche in legno?

After a brief summary of the different timber framing which can be found in the ancient architectures, the Authors list some examples of repairing that they feel anthologically distinctive as far as restoration of existing  timber framing is concerned.  The description is aimed to highlight the distinction between traditional and innovative techniques and anyway, between the ones giving reversible results and the others with non-reversible outcomes.

KEY-WORD: reversibility, building renovation, timber work requirements, ancient timber framing, Piedmont, timber restoration.

 

Carlo Serino, Antonio Iaccarino Idelson

Perni per l’assemblaggio reversibile di manufatti frammentari

New reversible dowels for conservation of small and middle sized stone artefacts are described.

They are conceived for facing the problem of reversibility when there is no access to the dowel after the two surfaces have been joined. Dowels are used as the traditional ones, but can be opened with a two step procedure: at first the pieces are pulled apart along dowel direction, they can be then separated by opening a safety lock or by cutting the exposed part of dowel. This provides a reliable bond even in case of accidental opening of joint.

Some case histories are presented, and also a simple method for making coaxial holes in stone surfaces that need to house a pin.

KEY-WORDS: reversibile dowel,  metal reinforcement, titanium, stone, de-restoration,  reversibility.

 

Guido Biscontin, Elisabetta Zendri, Guido Driussi

Reversibilità e prestazioni delle operazioni e dei prodotti per il restauro

The termodynamic reversibility is not always applicable to the conservation field. The “reversibility” level  depends on the typology of the restoration’s operation and generally is necessary to reach a compromise.

In this paper are also analyzed some methods usually applied for the evaluation of the reversibility of protective and consolidant products and the characteristics of the “reversibility” are discussed.  

Key-word: Reversibility, evaluation, water absorption

 

Donatella Rita Fiorino

Reversibilità e smontabilità nei progetti di gestione e fruizione dei beni archeologici: i casi dell’anfiteatro romano di Cagliari e del teatro romano di Nora a confronto con le prescrizioni internazionali e altri modelli di intervento

The main goal oft this work is to point out the role of reversibility and dismountable structures in the valorisation projects of archaeological heritage. The actual wish to use archaeological sites for public entertainment without dangering ancient ruins, is leading to an immoderate use of dismountable technologic systems able to hold many spectators, but at the risk of bury and forget our properties and monuments under a steel cover. Moreover the research for reversibility induces to the construction of a series of provisional and temporary structures such as cantilever roofs, fencing, paths, and so on, often not really good in terms of quality of design and of environmental interference.

The positioning and assembly of structures reveals only partly reversible even if dismountable especially in the joint between structure and litic support, damaging seriously the monument.

The analysis starts from the symbolic case of rehabilitation projects for the roman amphitheatre in Cagliari and continues with the example of the roman theatre in the Nora Bay in Sardinia. It is also proposed a formal to follow for the cataloguing of little systems for the fruition of sites with specific reference with their level of reversibility.

KEY-WORD: reversibility, dismountable structures, fruition of archaeological sites, accessibility.

 

Maria Grazia Vinardi, Marie Helene Cully

La ritrattabilità e la durabilità nella conservazione delle superfici: il portale di santa maria di castello ad alessandria

The essay illustrates the conservation works realized on the XVth century portal of  Santa Maria di Castello’s Church in Alessandria. The writing evidences the question of retractability of the superfaces in relation to the application of consolidating treatments made up of oils and protein substances used in the past.

The difficulties that emerged from this building site refer, on one side, to the intangibility of the very degraded superfaces, and on the other one, to the necessity of the elimination of dust and other particles laying on the portal. These phenomena need to be connected to the compatibility of the new intervention with the previous one and to the necessity to guarantee its duration in the years, its effectiveness and its retractability. The operations led with the restorer and the technician of the cleaning laser, give evidence to the minimal intervention, paying attention to constant need of control of the restoration works.

KEY-WORD: Piedmont, Portal of Santa Maria di Castello’s Church in Alessandria, compatibility, minimal intervention, planned maintenance

 

Lucia Serafini

Reversibilità e architettura sulle preesistenze. Questioni di metodo nel rapporto tra antico e nuovo

The theme of reversibility goes with the history restoration since the beginning of its modern approach. The enlightenment reply to the scientific nature petitions made by a culture already aware of the separation between past and present, the principle of reversibility was proved with the passing of time to be as much effective in the pictorial field as vulnerable to the scale passages defined by other figurative arts, mainly architecture. Its dimensional differences, linked to the specificity of its irreversible interactions between form and substance, have exposed this principle to troubled debates on its adequacy to the architectural restoration both in terms of theoretical legitimacy and practical implementation.

The intent of this contribution is willing to verify the topical interest of this debate, through the example of some recent interventions on ancient buildings, where the meeting between Old and New seems to be more successful as being more emancipated by the principles needs, and subject to the need of a true relationship where the disagreements between shapes, materials and technologies make the way for calmer discussions, which are often the more effective the more they clearly result by the interaction between the parties.

Key-Word: Reversibility,  old and new, materials and technologies, tradition and modernity.

 

Alessandra Maniaci, Olivia Parisi

La reversibilità nel costruito storico: lettura e analisi critica delle architetture “stratificate” in Sicilia.

As time goes by the believing in the  possibility of the reversibility” in the restauration has involved the use of different methodology and experimentations of techniques and materials of witch they couled not be know the  effect on the “  formal  and  material original integrity”. The pratice has been accertained the real difficulty of intervene in the built in the respect of this principle and the  at times extreme  incompatibility of the materials used, that, in the long run, have  baited process of irreversible  degrade. The  wish to return the object his formal integrity and bring again it “to the maximum splendour” has done as to retain possible to eliminate the stratifications and the  juxtapositions  (previously introduced to adjust  the  manufactured article  to  use  and different demands) as if those juxtapositions could have been automatically cancelled without  any  trace. But that is not how it  is, and we  wont to prove  how it is, and we  wont  to prove  how each intervention on the  built is essentially irreversible. Some buildings / document will be analysed, particularly in the Sicilian area, to empathise the interaction that have developed between homogeneous or not, fixed or movable materials that have come in contact and sometimes in contrast of the matter and which existence and duration  produced indelible and incontrovertible  irreversible  signs.

KEY WORD: Restoration, safeguard, irreversible, building/document

 

Bruno Billeci, Gabriela Frulio

Dal riconoscibile al reversibile: restauri in Sardegna tra XIX e XX secolo

The aim of the present paper is to analyse in chronological order some restoration works in Sardinia, since to the and of the XDC century. In such works the theme of the recognisable action is a peculiar characteristic not theoretical but technological, in order to be able to correct or substitute the restoration action. This theme hold some ideas still valid for the development of the actual debate. Contextually are critically analysed some early restoration works, until today, where the theme of the reversibility on the action has been the guideline for the project, specially on works belonged to the local office of restoration authority (ministry of the culture): structural restorations, replacing of the missing parts, chemical restoration, prescriptive adapting, re-utilisation.

Key-word: Sardinia, recognisable action, reversibility, prescriptive adapting, re-utilisation

 

Antonella Postorino, Laura Messina, Sergio De Vivo

Rapporti e contraddizioni tra reversibilita’, compatibilita’ e durabilita’, negli interventi di recupero dei centri storici della provincia di reggio calabria

The approach of the reversibility can change in the case in which the object to be restored is a work of art of painting or sculpture, an architectural monument, an historical center or the landscape, and to the meantime it has to express itself in appropriate way inserting itself in the contingent reality of the object to preserve.

The historical centers are not anything else other than big monuments materialized in the union of so many values: environmental, historical, physical, cultural, economic and social. The broad value of a historical center finds nourishment in its material culture, therefore it’s important that any human action can upset the equilibrium consolidated durign the time, between the man and the environment. We haven't to forget the difficult contact with the reality of a territory in which the earthquakes have made everything provisional, beginning from the houses ‘baraccate’, up to the conditions of instability of the structures tried by the shakes, therefore the sense of temporarily determined or of precariousness that can make to intend the concept of reversibility (even if so it is not) how can be understood from the point of view of the psychological appeal? Can it make to collapse the myths of the certainties (stability, safety, protection, continuity) that it has to offer the house for the life?

Key- words: material culture, project of maintenance, natural/artificial materials, wood, mortar, plaster, technological innovation.

 

Fabio Bevilacqua, Anna De Palma

La reversibilità' dell'intervento virtuale per una migliore definizione delle scelte progettuali irreversibili. Un caso di studio sulle superfici intonacate

Gli interventi di restauro virtuale consentono di prefigurare i risultati esecutivi del progetto, passo dopo passo, come se si operasse sul corpo reale della fabbrica, ma con operazioni assolutamente "revocabili". Il tema della reversibilità è quindi ricondotto nei limiti dell'attività predittiva concessa alle fasi progettuali. Questo contributo intende sperimentare l'impiego delle tecniche di elaborazione dell'immagine nella conservazione delle superfici intonacate, settore nel quale la diversità e la varietà delle situazioni creano non poche difficoltà di valutazione dell'impatto del restauro finale, specie nei casi in cui si intenda conservare il più possibile le stratificazioni originali e il progetto si ponga l'obiettivo di lasciare tracce intenzionali non equivoche. In tale contesto può rivelarsi utile, prima di agire direttamente sulla fabbrica e senza affidarsi esclusivamente alla capacità di immaginazione del progettista, vagliare le soluzioni più idonee attraverso le simulazioni.

Keywords Reversibilità, realtà virtuale, intervento restauro, intonaco, velatura

Carla Benocci

Quale reversibilita’ per le copie di sculture nelle ville romane ?

The custom to remove the sculptures from the historical gardens to preserve them has constituted an important measure for them preservation. The substitution with copies was the first step of the restoration of the comprehensive image of the monument, but without equivalence between original and copy. The question of copies reversibility opens a full discussion: the finally objective is put the originals on again, with the necessary measures to guarantee the safety and the preservation. These measures involve heavy political, economic and social decisions and regard all the management of cultural estate. An intermediate phase about reversibility could be to create a museum of the original sculptures in the same historical garden: it will be possible a better understanding of historical contexts and a good preservation of very damaged sculptures.   

Key-word: copies, sculptures, museum, safety systems, Museo della Villa Doria Pamphilj

 

Vittorio Giola

Reversibilità e smontabilità di aggiunte in legno lamellare a un complesso monastico quattrocentesco.

This article concerns the project case study and the following development of light laminated-wood structures added to create a cloister and a cross vault in a complex of Monastery buildings dating back to the fifteenth century. These new structures are part of the restoring works carried out to preserve a former Olivetan Monastery built in 1468 in Nerviano (Milan) and dedicated to the Blessed Virgin Mary Crowned. The complex is a public property where the Municipality, the civic room and the library are seated.

The study focuses on acknowledging reversibility as a utopia and on defining more appropriate concepts, such as disassemblability and removability which reflect the project guideline for minimum interference between the additional architectural and functional elements and the historical building. Very peculiar solutions have been adopted with a very low impact on the existing building, thus ensuring the historical process both for the past and the future.

KEY-WORDS Reversibility, Removability, Disassemblability, Monastery, Arcade, Cross vault.

 

Luciano Roncai,  Elisabetta Bondioni, Stefania Terenzoni

Il torrazzo di cremona: interventi di conservazione

The preservation and safety project carried out on the Torrazzo of Cremona between the autumn of 2001 and the spring of 2003 was in response to the necessity to stop the decay of the stone materials on the monument’s external faces, in certain cases in impending danger of falling in the form of fragments, and in any case risky for the safety of passers-by.

The restoration work has presented the present operator with a wide variety of conservational problems: with regard to the methodological and practical answers, reversibility has been achieved in almost all the themes confronted in the course of the project, except where safety requirements had to be respected.

Key-word: Torrazzo of Cremona;  restoration; reversibility; safety.

 

Chiara Calderini, Sergio Lagomarsino e Stefano Podestà

Reversibilità e sicurezza: il consolidamento della volta dell’ambulacro del castello dei fieschi a torriglia (ge)

The paper aims to illustrate an example of structural intervention where reversibility features are strictly connected with safety and conservative ones. Reversibility is here conceived as “tool” for preservation more than a theoretical assumption. Moreover, the possibility of a conservative use of concrete, in order to bring back the ancient structure to its original behaviour, is shown.

The structural preservation project on the “Castello dei Fieschi” in Torriglia (GE) is presented. FEM analysis of the original and repaired structure illustrate the structural meaning of the project.

KEY-WORDS: reversibility, structural preservation, masonry

Michele Candela, Enrico Guglielmo, Pierino Vacca

L'abbazia di san Michele Arcangelo sulla terra murata nell'isola di Procida. Reversibilità' ed evidenza dell'intervento di consolidamento strutturale con impiego di catene ed apparecchi di collegamento non convenzionali

In the consolidation and restoration works for the parsonage of San Michele Arcangelo, in Procida, Naples, it has been possible to define the scope of work, the technical-operative interventions, the structural remedies, intended as a whole, consistent plan, only after assessing the status of the parsonage itself, as well as of the side wall of the main abbey. The reading and interpretation of the cracks situation was even more diffìcult owing to the "hiding" produced by the previous interventions and related methods. In the absence of any restoration works, in fact, a cladding system and mutual links by means of reinforced curbs and tie-rods (made with bundles of round irons) had been placed against the rather inadequate wall thickness. The idea of visibility of the intervention has guided our restoration works that give structural remedies their full architectural potential, aiming to' spatial characterization and figurative quality. The intervention was notably simple, totally reversible and clearly evident. It is easily applicable to all cases, rather common, of walls in need to be anchored to structures behind them, whose solid nuclei are not positioned according to the alignments, which would allow for an ordinary disposition of steel tie-rods.

KEY-WORD: wide-spread cracks, oxidation, restoration's restoration, reversibility and evidence, non-conventional linking system.

 

Emine Pinar Dogu

The immence quality of sizing in reversibilty in restoration

In Ottoman bookbindings and inscriptions the papers, which were used in between XIII- XIV centuries. were mostly Middle Asia originated. Starting from the last decades of the XIV. Century they started using the papers coming from northern Italy. All the papers used in books and inscriptions are treated with a special material so called aher . The main purpose of this treatment is; Sizing forms a protective layer on the paper. The ink and the dyestuff used were and still is water based. The untreated paper tends to absorb the liquid (dye and ink) and in case of a mistake or ink split, a reverse action with an untreated paper is impossible. Ahered (sized) paper gives the opportunity to the person to erase or lick (the traditional way of getting rid of the errors or scrape the mistaken area without leaving any trace of it and also without harming the paper surface.

KEYWORDS: Sizing (Aher), Polished (Mühre), Egg size, Sized paper

 

Elena Boldetti, Carlo Dusi

Considerazioni in merito alle principali tecniche di intervento sui solai lignei: efficacia, reversibilità, compatibilità ambientale.

Nell’ambito di un intervento eseguito sul solaio ligneo tardo settecentesco di un appartamento d’abitazione nel centro storico di Cremona, che presentava i sintomi caratteristici del degrado propri di tali strutture, si è approfondito il confronto la più diffuse metodologie di intervento, individuando una porzione di solaio ‘campione’ e testando su questa le tecniche, da quelle tradizionali a quelle più recenti di uso comune.

Si è effettuata una approfondita ricerca sulla manualistica e sui trattati, nonché una indagine sul campo (restauratori, imprese di restauro) per individuare le più diffuse tecniche di intervento. Si sono quindi schedate e verificate le ricette (reperibilità dei materiali, eventuale tossicità, costi) e le tecniche di applicazione, con l’obiettivo di verificarne l’efficacia, la durata e la reversibilità.

Una volta poste in opera, le tecniche di intervento sono state monitorate e confrontate sotto molteplici aspetti (efficacia, reversibilità, modalità di applicazione, durabilità, sicurezza degli operatori, rispetto dell’ambiente).

KEY-WORD: solai, legno, stucco, Cremona

 

Fabio Todesco

L’intervento come strato di sacrificio o come materia dell’opera? Livelli di reversibilità nel progetto di conservazione della statua di messina riconoscente alla sovrana concessione del porto franco

The statue of Messina riconoscente alla sovrana concessione del Portofranco has been reduced in pieces after the earthquake that destroyed the city in 1908. In the seventies of the last century it has been restored using concrete mortars and metallic elements. This method revealed, in time, its inadequacy to resist against a very aggressive context. The recently intervention, aimed at slow down degradation, imposes a reflection about all the possibilities that called technicians to choose between different methods: for example if it is better an intervention based on a simple opposition to degradation rather than another one that use deepened preliminary investigations. In the present case it was not possible to run through this second way, always wished but that requires a more long time, because of the condition of the statue that required rapid interventions which had to impede at degradations to injure definitively the materials.

KEY WORDS: statue, concrete mortars, metallic elements, degradation, restoration, reversibility

Giovanni Cavallo, Simona Del Pietro, Chiara Lumia

Reversibilità e irreversibilità nei restauri sui dipinti murali in Canton Ticino nella prima metà del novecento

Il contributo analizza nello specifico le problematiche di reversibilità e irreversibilità in tre casi di intervento su manufatti ticinesi: la chiesa di S. Maria degli Angioli a Lugano, la chiesa di S. Nicolao a Giornico e la chiesa di S. Francesco a Locarno. La ricerca è stata condotta mediante ricerche d’archivio, bibliografiche e sulla base delle risultanze di indagini di laboratorio effettuate su alcuni microcampioni prelevati dagli edifici. Le problematiche emerse sono analizzate valutando l’incidenza del concetto di reversibilità nel clima intellettuale del restauro ticinese; il contenuto culturale e la elaborazione delle scelte; le eventuali modalità applicative nella prassi operativa; le connessioni con la compatibilità, efficacia e durabilità dei trattamenti conservativi con la natura del supporto. Parole chiave: reversibilità, autenticità, compatibilità, trattamenti, restauro, conservazione, affresco, intonaco, S. Maria degli Angioli, S. Nicolao, S. Francesco.

 

Chiara Lumia

Reversibilità e irreversibilità nella tutela e nel restauro in canton ticino nella prima metà del novecento

Abstract: This work analyses problems related to reversibility in the activity of conservation and restoration made in Ticino, from the beginning of 20th century to the years after the world war II, through a transversal reading of the official records, the texts and the research about some interventions. In the period taken in to account you can trace methods and lines of conduct which identify concerns and purposes directly or indirectly relating the issue of reversibility. From this point of view we have investigated the ideas and methods related to the restoration and maintenance experiences; to the questions of reversibility, consistency and durability of the interventions as a whole, of the techniques and materials used, analysing the meaning and the development of the intervention choices adopted for their reversibility degree.

Key words: reversibility, protection, restoration, conservation, authenticity, Cantone Ticino.

 

Giuliana Barilà

Sulla (ir)reversibilità degli interventi sulle fronti esterne dell’edilizia minore della sicilia nord-orientale

The research about conservation of façades of historical buildings in north-eastern Sicily comes from the consideration that only few traces of render have been conserved on the surfaces. Almost all the traditional techniques, adopted till the beginning of the 20th century, were abandoned after the earthquake of 1908, in favour of others considered more suitable in seismic areas and, in consideration of the great trust on cement as product of technologic innovation, were introduced new materials and techniques not only for refurbishment but also for not structural elements such as plasters and renders. Still today cement and silicates are used directly on stone and rendered supports without any regards of irreversibility and incompatibility among old and new surfaces. The report, using not destructive diagnostic techniques, studies the state of conservation of historical renders of constructions in the study area, compares traditional and new techniques and evaluates recent applications in matter of reversibility. The result has demonstrated the difficulty of having an effective reversibility in an intervention for conservation of surfaces; it clearly means that reversibility has to be considered as compatible activity.

KEY-WORDS: Façades, north-eastern Sicily, traditional techniques, render, diagnostic.

Claudio Spagnol

La chiesa veneziana di san maurizio: il restauro della facciata a trent’anni dall’ultimo intervento.

The previous restoration and consolidation operation on the frontal decoration of the church occurred thirty years ago. Synthetic resins were used as consolidation material. Today after that first restoration operation the situation is grave with several parts of the frontal decoration disintegrating.

The tests and the analyses on the decorative materials suggested that different approaches were needed during the new restoration. The bas-reliefs and the coverings were cleaned and the old resin removed where possible. Subsequently, damaged parts have been reconstructed and put back in situ using fiberglass pins/rods fixed with epoxy resins. However after a series of texts the statues were removed from their pedestals and relocated inside the church, prior to their substitution with copies. The previous restoration results, in this specific case, forced a radical

Keywords: synthetic resins, Pietra d'Istria, Pietra tenera di Vicenza (Pietra di Costozza), Biancone di Verona

 

Daniela Pittaluga

Interventi reversibili sulle strutture voltate? Esempi tra il XVI ed il XIX secolo.

L’analisi di alcune centinaia di strutture voltate condotta per conto di una ricerca Murst iniziata nel 1998 e continuata negli anni successivi (con Assegno di Ricerca a.a. 1999-2003), ha permesso di avere a disposizione un materiale particolarmente  ricco di informazioni sull’arte di costruire in periodo preindustriale.

L’analisi archeologica di queste strutture ha  consentito di distinguere gli interventi eseguiti sulle volte stesse contemporaneamente alla loro costruzione da quelli, invece, realizzati in tempi diversi (per motivi vari: trasformazioni, adeguamenti, riparazioni, manutenzioni ripetute, posizionamento di puntelli, ecc).

Tra gli interventi successivi sono emersi alcuni sistemi di cerchiaggio e di incatenamento con elementi in ferro e/o tramite nervature in muratura. In alcuni casi sulla volta ne permangono tracce più o meno consistenti, altre volte, ma più raramente, i segni sono molto contenuti. In alcuni casi si registra un unico fatto isolato, in altri sulla stessa struttura si hanno più operazioni successive. Talvolta questi sistemi raggiungono un buon livello dal punto di vista del rispetto materico dell’oggetto su cui sono stati applicati; altre volte il giudizio è decisamente sfavorevole.

Nell’articolo questi interventi vengono analizzati e confrontati alla luce del concetto di reversibilità.

In alcuni casi sembra ravvisabile una differenza di indirizzo in relazione alle diverse epoche storiche (propensione all’utilizzo di un sistema piuttosto che un altro).

Il periodo cronologico a cui appartengono le strutture (dal XVI al XIX secolo) e gli interventi sulle stesse (dal XVI al XX) permettono una buona panoramica.

Key-words: architecture archaeology, vaults, chains, reversibility

 

Fallahdar Hossein 

Concept of preservation and the Research on reversibility in restoration

n.d.

Vanni Tiozzo

Riflessioni sulla foderatura

Comparative test on the characteristics of adhesives for relining are been effected underlining the distinction between experimentation and intervention on the work of art. The application of the adhesives is been maked in one type of cloth for all the samples prescinding from the needs of the differents ways that will reguire differents cloths.  The analyzed adhesive have been five: two variations of glue of pasta; that to cold; the Beva; the Wax-resin. The effected tests have been: the verification of the increase of weight of the adhesive; the bending; the resistance to the tear of the adhesive to verify the different difficulty in the removal of the cloths of sheath. The tests have underlined a remarkable difference of physical behaviors in relationship to the adhesive, putting in evidence as none of them introduced the best characteristics on all the positive considered parameters, thats is: lightness, flexibility and facility of separation.  For this reason it make stronger the belief that any procedure of restauration can be intended curative of the conservative conditions of the work of art, even if it can result essential to obviate conservative deficit of the same one.  In second place are been perceived the different characteristics of permeability of the structure after the treatment, even if not documented with specific experiments, and therefore as the use of the glue of pasta, with the most balanced chart of positive characteristics, result more convincing for all those works of art already defined traditional, that is in the painting untill the second half of the eighteenth century.

KEY-WORD: painted cloth, Relining, Wax-resin and Glue-paste Lining.

Moreno Binci, Marcello Agostinelli

Rappresentare la reversibilità

Reversibility should immediately be assessed in the initial stages of any restoration project; the materials to be used must be compatible, with proven durability; where and how they are placed will however impact reversibility as well as level of potential removal. The intervention must be planned with particular care, clearly defining details of the working method and corret use of materials. What is reversibility? It is the possibility of taking apart and removing, with a graphic description monitoring the deconstruction and subsequent re-assembling procedures. This process naturally encourages full and effective consideration of a minimum intervention, i.e. one limited to what is strictly necessary.

This presentation proposes a new project planning computer technique which can be considered as being at the frontier between traditional paper-based and new multimedia planning approaches. The latter provide a valuable facility to explore step by step the assembly of each of the construction details. Such a computer based interactive approach offers the possibility of extrapolate the techical components, to identify basic architectural details, level and kind of deterioration and proposed method of intervention, and, inversely, using these various components, to examine how the specific project fits the general architectural body.

KEY-WORD: reversibility, representation, multimedia planning approaches

Benedetto Pizzo, Mario Moschi, Paolo Lavisci

Valutazione quantitativa del grado di reversibilità nel restauro di elementi strutturali lignei

The consolidation of wooden structural elements is executed when a form of degradation is present, either of biological type (like attack by mushrooms or insects) or mechanic type (like breaks and disarrangements). In order to avoid the replacement of the whole beam, the most diffusing technique of intervention consists in only substituting the decayed head by mean of a solid wood prosthesis “sewn” to old wood through bars, in steel or other materials, glued with epoxy adhesives.

This type of intervention introduces some elements of irreversibility: the cutting off of some sound wood is required to securely connect the prosthesis with the old wood. But on the other hand, an intervention is necessary because of the irreversible presence of the degradation. Then, it is correct to ask oneself if a structural consolidation has to integrally be reversible.

Based on these considerations, the present contribution proposes a possible definition of the ‘reversibility factor’ referred to the specific case of the interventions on decayed wooden heads. This quantity considers measurable parameters involved in the interventions, like the volume that has to be removed for disassembling the prosthesis, and it enables to quantify the amount of the permanent alteration caused to the wooden element. A criterion of acceptability of the interventions based on the ‘reversibility factor’ is also given.

Monica D'Agelantonio, Zuleika Esposto, Francesco Trovò

Gli interventi sulle superfici intonacate veneziane. valutazioni in ordine ai requisiti di reversibilità.

Reversibility, as cultural constituted requisite, could be broadly speaking meant Repeatability, especially reguarding plasters of external fronts of Venetian historic housebuildings.

About five different ways of intervention on them have been individuated but the highest percentual of the works is concerned of demolition and then sostitution of plaster. The new plaster is generally different in materials and tecniques of realization, making neglected the principles of Preservation.

In facts the ultimate end of Preservation is to extend the treatments of a building, in order to appreciate its peculiarities and its historical and documental values.

For these reasons moderating the various impacts of daily works on the external fronts of Venice, in a preservation sense, thinking about building matter, relationships between plaster and the architecture of building, about the proper image of the City and its memories, is the purpose of the Plan of Surfaces we suggest.

Key-words: Plaster, Venice, Repeatability of works, repeatability of treatments, demolition, compatibility,  perceptive impact, plan of surfaces.

 

Piero Gelfi, Ezio Giuriani

Aspetti di reversibilità nel consolidamento di volte in muratura

In this paper a reinforcement technique is presented, which employs a light but cohesive backfill material, such as concrete lightened with polystyrene. The simple substitution of a heavy backfill material  with  a  lighter  but  not  cohesive  one,  even  if    reduces  the  vertical  load  and  the  thrust  at abutments, worsens the static behaviour of the arch since the thrust line trace is more influenced by the live loads. Instead a cohesive backfill works as a diaphragm that contains the flexural actions also in the particularly unfavourable conditions of concentrated or asymmetrical loads. The proposed backfill material is non invasive, can be easily removed, due to its poor resistance, and therefore the rehabilitation intervention can be reversed.  The  technique  has  yet  been  used  in  some  rehabilitation  interventions  on  historical  buildings.  A series of experimental tests on a physical model of masonry vault is herein presented.

KEY-WORDS   Backfill material, vaults, arches, rehabilitation. 

 

Luca De Bonetti, Roberto Madorno

il portale di S. Vigilio al castello del Buonconsiglio, individuazione e reversibilita’ degli applicativi impiegati nel corso dell’intervento del 1981, per il restauro del 2002.

The complete restoration works of the portal (made in local white and red limestone) has begun after the completion of a series of analysis done under scientifically accepted standards, and however useful to characterize the methodologies to carry out the appropriate works. One of the first angles realized during this introductory survey, was to identify the old strengthening polymers used on the stone ornaments during the works performed in 1981, works that could be defined the first portal restoration works.

The reversibility sublet came out during the samplings for the surfaces cleaning, when some deep purplish stains where examined and turned out to be a resin applied during the first intervention.

The need to find the reversibility of the resin used during the old consolidation work was of fundamental interest.

Keywords: reversibility / polyurethanic resins / stone restoration / stone cleaning / St. Vigilio Portal / Buonconsiglio Castle Trento / Trento / uv fluorescence and resins / strippers tests.

Atanasie  Popescu, Charles Nelson, Jay Brandle,

Reversibility in restoration: the particular case of some historic mansions from  Duluth, Minnesota, USA

The reversibility in restoration of the American architectural heritage started to be applied later as in Europe, mainly in connection with the tendency to discard deteriorating materials or whole buildings and start over from scratch. This attitude could also be influencing the “quick fix” treatments which are really not fixes at all, treatments which have included uncontrolled application of epoxies, silicones, nonbreathable cementous coatings, etcetera. Among the main places with American representative monuments, an important position is represented by Duluth, a major port on the Minnesota Shore of Lake Superior. The main building material of Duluth’s mansions is represented by redstone, a type of sandstone delivered by some quarries located in the Upper Peninsula of Michigan. This paper describes the main deterioration factors of the stone and brick masonry of these mansions. Our comments are focused on various restorations or repairs of three important mansions from Duluth’s area, with various degrees of  reversibility.

KEYWORDS: redstone (Lake Superior sandstone); historic mansions; deterioration of building materials; the reversibility in restoration applied in the USA

 

Serena Viola

Interventi per il tessuto urbano di Ortigia (SR): la reversibilità come parametro per la selezione delle  tecnologie di intervento

In the last twenty years, the Municipality of  Siracusa has been managing  a  complex  urban spaces rehabilitation process, enjoying of extraordinary financial resources and of an appropriate coordination strategy  between all the  authorities involved. A urban  unitary image  saving the existent identity, has been  defined as the primary aim for any rehabilitation operation. Starting from a study on  local materials and  ancient  technologies,   acceptability thresholds for restore and requalification interventions  have been defined. Taking into account  cultural strategies  behind restore interventions  realized  on urban empty spaces of Ortigia, the research defines design scenarios  as a sort of pursued  vocation that can be achieved  with an appropriate selection of materials and  technologies. Assuming the Piazza Duomo restore operation as a case study, the research  comes to a performance grid,  affording on reversibility of the design solutions.

Key-words: ambiente urbano, tecnologie di intervento, prestazioni, identità

Giuseppina Suardi, Elisabetta Rosina, Alberto Grimoldi, Antonio Sansonetti

La volta absidale dell’abbazia di viboldone (milano): la reversibilità a garanzia della conservazione

In 2002 a delicate restoration of the apse vault was accomplished in the Viboldone Abbey. The plaster of the front half vault has a decoration: it is a Sinopia of the holy Trinity, never frescoed.  During the scraping of the non adequate patches, in the texture of the vault appeared a transversal cut, 4-7 cm large and 3 m length, crossing the whole thickness of the masonry.

A preliminary thermography of the surface (november 2000) detected the corresponding thermal anomaly, but the kind of the discontinuity was determined only in 2002, by removing the plaster. The authors took a complete documentation of this anomaly (comprehensive of the microscope analysis of the mortars and finishing) for further researches, and within December 2002 the restoration was completed by sealing the cut, in order to prevent any dangerous falling of pieces and quoins from the vault. The criteria of the intervention are addressed to preserve any evidence and traces of the occurred changes to the sinopia and the cut, in order to document the changes of mind and taste regarding the decoration set in time.

KEY-WORDS: Sinopia, masonry vault, IRT, SEM Microscopy,

 

F. Bandini, I. P. Mariotti

La reversibilità del ritocco pittorico sulle pitture murali particolarmente esposte agli agenti atmosferici

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Alberto Felici, Mariarosa Lanfranchi, Giancarlo Lanterna, Maria Rizzi

Alcune esperienze nell’uso del ciclododecano nel restauro delle pitture murali

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A. Moropoulou, N.P. Avdelidis, G. Haralampopoulos

THE COMPATIBILITY OF CONSOLIDation materials and treatment to the masonry stone as a prerequisite to a reversible conservation intervention

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T. Sali

Reversibility principles in the design of shelters over open air museums

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