C. Genovese

Il consolidamento dei mosaici in Sicilia tra Otto e Novecento, dibattiti e sperimentazioni.

Between XIX and XX century, in Sicily there was some experimentations on restoration of normans mosaics. In fact, in the middle of XIX century, the strategy of destruction and renovation of the ancient decorations begins to change, with the start of consolidations of mosaics.

Through the study of documentation exsisting about restoration of some middle age mosaics, as the Cappella Palatina in Palermo and the Dome in Messina, we can follow the evolution of conservation of mosaics in Sicily, with the progressive admission of the value of authentic materials of these historic decorations.

KEY-WORD: mosaics, Sicily, conservation, consolidation.

 

M. Camaiti, B. Sacchi, L. Borgioli, M. Gombia

Il consolidamento del travertino: valutazioni sull’efficacia dei prodotti.

Travertine, a carbonatic sedimentary rock with good compactness, is affected by different alteration processes. At present the main treatments carried out on this stone consist in filling the superficial cavities with plaster that produce a protective action from water and dusts on the underlying structure. In this work, a preliminary study on the effects of organic polymers based conservative treatments has been carried out. The durability of the treatments has been evaluated in presence of soluble salts and under thermo-hygrometric variations. Water capillary absorption, colour changes, liquid water diffusion and drilling resistance have been monitored during accelerated ageing test.

Key-word: conservation, travertine, organic products, consolidation, MR Imaging, drilling resistance

 

C. Tedeschi

Aspetti e riflessioni sul consolidamento degli apparati musivi della cupola di san Pietro in Vaticano: storia, tecniche e materiali.

In 2005, after Giovanni Paolo II’s death, I was called with emergency in order to check the conservation states of some mosaics on the dome  of the basilica of San Pietro in Vaticano. The mosaics are from 1598-1599. The mortar looked like some areas strongly pulverization and breakup.  The restoration work concerned mainly the consolidations in deep trough infiltration. Very interesting  were the mortar’s components  whose analysis showed  a particular composition based on lime and vegetal components. Never theless were some problems about the consolidation trough the compatibility between ancient and new materials. Some important compositional studies were very precious in order to establish the material for the consolidation and to start several general considerations about  consolidation skills.

Key-Words:  San Pietro in Vaticano, dome mosaics, chemical analysis, detachment, vegetal mortar.

 

M. Boriani, M. Giambruno, R. Simonelli, L. Toniolo, D. Gulotta, A. Paradisi

L’apparato decorativo del fronte ovest del castello Mediceo di Melegnano. Dal “disvelamento” alle linee guida per la conservazione.

this paper discusses the conservation project of the west façade of the Medicean Castle of Melegnano, from the knowledge of materials to the set up of the conservation guidelines. It includes the on site survey of the different materials and their degradation pathologies, the discovering and mapping of graphic decorations of the plasters, the mineralogical and chemical characterization of mortars and, finally, the development of a pilot conservation yard. The cleaning, consolidation and protection methodologies were selected at the aim of performing an integral conservative project. The work should be focused in order to ensure the maximum degree of material conservation, thus reducing drastically the degradation rate.  The plaster consolidation is the most significant and risky phase of the conservation work. Starting from the analysis of the state of art of this issue in the literature, three different consolidation methods were proposed and tested on site. The methodological approach allowed us to define suitable guidelines for the final plan.

KEYWORDS: lime mortars, plasters, decohesion, consolidation, conservation methods

 

C. Blasi, E. Coïsson

Le fratture nelle pietre del Panthéon di Soufflot: un problema statico e di conservazione delle decorazioni.

In the practice of restoration of historical buildings, the structural retrofit is often considered as an operation separated from the surface preservation, and is usually carried out by different experts. This is a wrong attitude, as it should always be considered that static problems influence surface conservation and that structural retrofit has often heavy consequences also on the aesthetics of the buildings. A clear example of this strict correlation can be seen in the French Panthéon, in Paris, built at end of the XVIII century in stone masonry reinforced with iron clamps. The cracks that in the latest decades caused the detachment of stone fragments from the ceiling and the partial closure to the public, were first related only to the water infiltrations and to the subsequent corrosion of the clamps, thus only local interventions were carried out. Recent studies have indeed showed how the crack pattern is related to the low ductility of the reinforced masonry, and that without this static problem, water couldn’t have reached the iron clamps. Thus the preservation of the surface stone decorations requires not only the elimination of the water infiltrations, but also the reduction of the structural deformations that first brought to the crack openings. The safeguard of the Panthéon, in which every stone is at the same time architectural and decorative component, must therefore pass also through the static retrofit of the structure.

KEY-WORD: French Panthéon, stability, preservation, stone, decorations

 

D. Pittaluga

Consolidare le cortine murarie e gli apparati decorativi in laterizio.

Cosa si intende per consolidamento di una cortina muraria o di un apparato decorativo in cotto?

Si intende un complesso di operazioni in grado di dare consistenza e struttura ad un materiale che in certi contesti può essere anche molto vulnerabile e facilmente attaccabile dal degrado, ma significa anche non perdere cromie e sfumature cromatiche (legate ad esempio a mattoni composti con argille diverse accostati a scopo decorativo), differenze di trattamenti di superficie …

Significa non alterare spessori e non modificare in alcun modo le differenti porosità che, ad esempio, si possono avere tra mattoni molto cotti e poco cotti posti a fianco per ottenere un particolare effetto estetico.

Altro problema: molte superfici in laterizio sono lavorate superficialmente….un consolidante che crei pellicole di spessore, anche limitato,  può annullare queste differenze.

L’articolo si propone, attraverso l’esame di alcune cortine murarie di edifici senesi e di alcune fabbriche in mattoni del basso Piemonte e la disamina di alcune prescrizioni descritte nei manuali otto-novecenteschi, una verifica ed una valutazione dei modi di procedere nei consolidamenti in epoca storica.

(K-Words: briks, coutani-walls, tradizional finishing, surface, mortar, stratigrafy, archaeology, consolidation, conservation)

 

L. De Bonetti, R. Madorno, G. Nerobutto, V. Recati, S. Ubaldi

Torre dell’Aquila al Castello del Buonconsiglio: studio e consolidamento delle superfici intonacate e degli apparati lapidei.

The conservation project has considered the strengthening of old plastered surfaces that for most area of this has ascribable (dated) at the 15th and 16th century. Because there are many factors that may influence the ability of the common consolidant to bond to the surface, such as the catalyst type, coupling agent, solvent content, outcrop salts, free and linked water content into ancient stones or plasters, black crust old consolidation based on various polymeric treatments, etc. the studies of consolidants and it blends performance had evaluated and then addressed toward the choice of waterborne alkoxysilanes for the ancient plasters and an special ethyl silicate family (butyl silicate with 317of molecular weight) chemically linked with methyltrimethoxysilane and aminopropyltrimethoxysilane / ureidopropyltriethoxysilane like a blend of coupling agents (slow rate moisture triggered and adhesive functions) for ancient sandstones of the main windows

Key-Words:   Consolidants – Coupling agents – Moisture triggering agents – High molecular weight

 

P. Bensi, O. Doria, C. Gardella, F. Passano, M.R. Montiani, D. Pittaluga, L. Taccia, S. Vassallo

L’Oratorio di S. Chiara a Bogliasco (GE).  Un intervento conservativo nel rispetto dell’esistente.

L’attuale edificio  della Confraternita di S.Chiara di Bogliasco, nata nel 1403, fu costruito  tra il 1631 e il 1641.  E’ possibile seguirne le vicende costruttive attraverso la ricostruzione storica di P.Gardella, che esamina  i documenti  d’archivio.  Presenta tuttora un’aula unica , illuminata da finestrone termale, con copertura a capanna .   Il campanile a pagoda è del 1681.

L’interno , arricchito  negli anni ‘80 del XVIII secolo di  una pavimentazione marmorea e di una boiserie di un sobrio ed elegante barocchetto, conserva pregevoli opere d’arte.  Nel 1827, a seguito dell’apertura di via Mazzini (1817) la fronte fu ornata dal pittore  Damantini con dipinti murali raffiguranti S. Chiara in gloria con ai lati  le allegorie della Fede e della Speranza.  Le figure necessitarono di un primo restauro nel 1883 da parte di O. Multedo.

Nel 1975 vi è stato un ulteriore ripristino in cui, come hanno evidenziato le analisi eseguite  da Doria e Vassallo, sono stati usati  calce e terre colorate, riprendendo quindi le tecniche tradizionali (pigmenti in acqua o latte di calce). Attualmente la facciata subisce l’attacco di licheni e degli agenti atmosferici che stanno provocando fessure ed erosione negli strati pittorici.  L’intervento in corso è finalizzato al consolidamento ed al mantenimento di tutti gli strati susseguitesi e alla salvaguardia della leggibilità nel rispetto delle tecniche e dei materiali tradizionali.

Key-words:  19th decoration, restoration, local and natural materials,conservation, layers

 

M. Camaiti, F. Fratini, M. Matteini, S. Rescic, L. Rosi, C. Colombo, M. Realini, L. Pellegrino

I Mosaici della Villa del Casale (Piazza Armerina-En): problemi di conservazione e proposte di intervento.

Travertine, a carbonatic sedimentary rock with good compactness, is affected by different alteration processes. At present the main treatments carried out on this stone consist in filling the superficial cavities with plaster that produce a protective action from water and dusts on the underlying structure. In this work, a preliminary study on the effects of organic polymers based conservative treatments has been carried out. The durability of the treatments has been evaluated in presence of soluble salts and under thermo-hygrometric variations. Water capillary absorption, colour changes, liquid water diffusion and drilling resistance have been monitored during accelerated ageing test.

Key-word: conservation, travertine, organic products, consolidation, MR Imaging, drilling resistance

 

P.L. Cosentino, P. Capizzi, G. Fiandaca, R. Martorana, P. Messina, I. Razo Amoroz, L. Pellegrino

Diagnostica per il consolidamento del mosaico pavimentale dell’Ambulacro nella Villa Romana del Casale  (Piazza Armerina).

The interest of "Villa del Casale" (Piazza Armerina) is mainly to be referred to the floor mosaics.

A new restoration plan was prepared by the Sicilian Restoration Centre, that includes the renewal of many of the facilities and technical supports (the roof, the lighting system, etc.) as well as the restoration of the walls and mosaics themselves. Many geophysical research has given support to the restoration plan: some investigations had already been carried out, however others are planned to continue during the restoration itself to control the results of consolidation. Here we present the activities that we carried out to investigate many of the technical aspects of the Corridor of the Big Hunting Scene. This Corridor has been characterized by a remarkable collapse effect. Therefore, we concentrated our efforts on the safeguard and conservation of archaeological structures that had already been partially studied and restored during the fifties.

We got various pieces of information on topics connected to the following problems: deep collapses in the southern part of the “Corridor of the Great Hunting Scene”, presence of underground voids connected to the subsided areas, reconstruction of natural and artificial (both ancient and recent) buried waterlines, recognition of the age and relative extension of various masonry walls and their geophysical characterization.

KEY-WORD: Geophysics,  Mosaic Floor, Past Restorations, Corridor of the Big Hunting Scene, Floor Consolidation.

 

A. Marino, M. Matteini, F. Fratini

Riflessioni critiche e nuove sperimentazioni sui trattamenti protettivi e consolidanti a base di ossalato di calcio artificiale.

Natural calcium oxalate patinas have been reported for 30 years on carbonatic stone surfaces of most of the monuments exposed to the open air. The origin of such patinas has been widely discussed mainly in two international congresses as well as the suitability of their conservation. Nevertheless it is commonly recognised that the conditions of conservation of the stone material below the oxalate patinas are always better than those of the next  material not covered by patinas. Therefore it is undeniable the role of protection performed by these patinas. According to these observations, fifteen years ago the Opificio delle Pietre Dure (and now CNR-ICVBC) began to study the possibility to realise passivating protective treatments for carbonatic stones based on the formation of artificial calcium oxalate starting from ammonium oxalate water solutions. In the following years the treatment was extended to other carbonatic surfaces like decorated plasters and recently to mosaics realised with carbonatic stone tesserae. The compatibility of such treatment with the carbonatic materials makes the surfaces highly resistant to the acid attack although maintaining the mineral nature, the hydrophilic properties and the permeability to water without interfering with the presence of salts. Beside the protective action, the numerous applications carried out in Italy made it possible to emphasize also a consolidating action of the artificial calcium oxalate which is better performed on degraded marble and decorated plasters (frescos and "sgraffiti").

KEY-WORD: consolidation, protection, oxalate, limestone, decorated façades, sgraffito façades

 

L. Corrieri,  P. Gasparoli

Il consolidamento degli apparati decorativi interni della Stazione Centrale di Milano.

The surfaces of the internal monumental areas of the Central train Station in Milan, which were built in ‘30s of last Century, are made in part with natural stone coverings, and in part with decorative concrete, to imitate travertine and Nabresina limestone, two of the most common natural stones in this building.

The rich decorations of Galleria delle Carrozze, of Sala delle Biglietterie and of Galleria di Testa, which are now in restoration within the Grandi Stazioni project, had problems about consolidation and safety, specially about the decorative concrete components.

The technical activities of consolidation and maintenance, although they were confirmed practices, are critical because of the monumental dimensions of the building and different conservation conditions. They need executing in several different parts to permit the ordinary and safety use of one of the most important National infrastructures. In addition they have to ensure a global result which must keep in line with the relevance of this building.

KEY-WORD: Central Train Station in Milan, conservation, decorative concrete components, consolidation and maintinance, consolidation and safety.

 

A. Alberti, F. Bevilacqua, M. Galeotti,  D. Pinna, S. Rescic

Il portale lapideo di palazzo Schifanoia a Ferrara: l’intervento di restauro e la valutazione di precedenti trattamenti consolidanti.

Palazzo Schifanoia, Ferrara was built in different periods, starting from a first edifice in 1385 until the wide modifications by Duke Borso d’Este in 1465. Just around this date the stone portal with the big coat of arms and, inside the building, the wall paintings of the Salone dei Mesi were executed. The portal, made up with Pietra d’Istria and partially painted and gilded, was placed in the façade having frescoes and simulating-marble geometrical decorations.

On the occasion of the recent restoration of the portal, various aspects, not yet investigated, has been studied:

-         the polychromy and the gilding on stone

-         the materials used in maintenance interventions carried out in the past and not documented

-         the stone consolidation performed with acrylic-siliconic resins in the documented restoration  dated 1981.

The scientific investigations carried out include the samples observations with optical and electronic microscopes, FTIR analysis, the measures with DFMS – Drilling Force Measurement System.

Key words: Palazzo Schifanoia, Ferrara, stone polychromy and gilding, maintenance interventions, evaluation of stone consolidation.

 

A. Nucatolo, M. I. Randazzo, F. Tomaselli, G. M. Ventimiglia

La chiesa di Santa Maria della Catena a Palermo e il restauro degli affreschi nella Cappella Maggiore. Conoscenza, diagnosi e consolidamento dei dipinti murali.

The essay introduces the searches concerning the church of Santa Maria della Catena in Palermo: the history of the restorations in the XIX century, the historical-artistic analysis, the non destructive diagnostic investigation and the consolidation of architectural surfaces.

KEY-WORD: Chiesa di Santa Maria della Catena, Francesco Saverio Cavallari, Giuseppe Patricolo, Olivio Sozzi, thermography, wall paintings restoration

 

P. Iazurlo

Supporti in cemento-legno per dipinti murali contemporanei: problemi di consolidamento e restauro.

The big restarting of mural painting technique in Italy beginning from the 1930’s goes along with a large diffusion of mural works made also on mobile support, often in relation to the big development of local and Unions art exhibitions.

In this field new solutions are adopted especially for the supports, where atypic and new materials are experimented, frequently borrowed from building trade, like eternit, eraclit or populit.

The last one, largely diffused, is wood - cement boards formed by strips of wood  mixed in cement Portland.

The use of these supports for the execution of mural paintings has caused specific problems of conservation, and particularly manifest phenomena of detachment of painted plaster from support. For these problems specific solutions have been worked out, avoiding water based products and valuing in order to it the adhesive power of acrylic resins in solutions, commonly used for problems of consolidation.

KEYWORDS: mural paintings, contemporary art, support, wood – cement boards, acrylic resins in solutions

S. Gizzi

Problemi di conservazione degli apparati decorativi dell’architettura gotico-catalana in Sardegna.

n.d.

 

M. Positano, T. Poli

La valutazione dei prodotti per il consolidamento superficiale: proposta di un protocollo di prove.

The work here presented summarizes three years of experimental activity carried out by ISRIM s.c.a r.l. (Institute for Research and Training in Specialized Materials for Advanced Technologies) and CNR – ICVBC Sezione di Milano “Gino Bozza” (Institute for Conservation and Valorisation of Cultural Heritage). Test methods have been specifically selected in order to evaluate the efficacy of consolidating products (mechanical and physical tests, colorimetric measurements and in situ tests). Six consolidating products, belonging to different chemical classes, have been used and four different stones, with different chemical, structural and mechanical properties, and two kind of stone-powders. Results have been critically evaluated and each test has been reviewed with particular attention to significance, reproducibility and reliability. The main advantages and drawbacks of the different test procedures have been highlighted. Attention has been focused not on the efficacy of each product on the four selected stones but on the effectiveness of each methodology in discriminating the behaviour of the different products and on the opportunity of inserting the tested methodology in a standard procedure protocol able to completely characterize the effect of a consolidating product on a decayed stone surface.

KEY-WORD: conservation, stone consolidation, compression and traction test, microdrill, water absorption, salt crystallization, in situ tests

 

H. De Clercq, S. De Zanche, G. Biscontin

Teos and time: the influence of application schedules on the effectiveness of ethyl silicate based consolidants.

An investigation was carried out at KIK-IRPA on the application modalities of ethyl silicate based products aiming at understanding the influence of time between successive applications on the pore structure and on the final strengthening effect of stones. Samples of Maastrichter lime stone were treated with different formulations and dilutions. The number of treatments varied from one to three with an interval between successive treatments ranging from one day to three weeks. Mercury porosity measurements, polymerized product content and hardness profiles obtained by a drilling resistance measurement system (DRMS) were used to evaluate the consolidating properties. Noticeable differences in pore blocking and in overall hardness were observed in samples that were treated at one day intervals and those treated at three week intervals. The strengthening effect also seems to vary with the type of formulation.

KEY WORDS:   Consolidant, ethyl silicate, application schedule, pore structure, DRMS

 

R.Bertoncello, M. Modolo, S. Voltolina, R.Codello, S. Magnani, E. Zucchetta, V. Achilli, G. Salemi

La vetrata del Vivarini a SS. Giovanni e Paolo (Venezia): Studio del degrado del manto vitreo e del suo vano di alloggio per una corretta progettazione dell’intervento.

Grandioso finestrone archiacuto a comparti, con magnifica vetrata quattrocentesca, dai meravigliosi smalti colorati. Sebbene molto restaurata, è una delle opere più insigni uscite dalle fornaci muranesi (Grand compartmented ogival window, with magnificent fifteenth-century stained-glass, decorated with amazing coloured enamels. Even though much restored, it is one of the most eminent artworks produced in Murano furnaces). Such description given by Lorenzetti [1], sets the features of the Grande Vetrata of the SS. Giovanni e Paolo Church in Venice and above all, it considers every single part of which this marvellous work of art is constituted. These different parts are: the stone frame in which the stained-glass window is allocated, the stained-glass window itself (made up of 66 panels), and the grisaille used to decorate the glass tesserae.

Looking at the precedent restoration works [2], it has been seen that the problem of the stone wall consolidation arose also in the past. Such a problem, however, was always considered second place as to the grisaille consolidation and to the image conservation.

A close up analysis of the artefact was made and all the weathering phenomena were documented. The documentation was carried out for every constituent of the work of art (glass tesserae, metallic retaining structures and stone wall) and particular attention was given to their interactions (i.e. the consequences of the wall movement on the stained-glass window).

The diagnostic work was conducted at different stages: characterization of the Building, Technological and Decorative Apparatus; analysis of their weathering and comparison of the data related to each apparatus.

The restoration project will have to aim to the consolidation and integration of the grisailles, where it will be necessary, but the consolidation of the stone wall and the rectification of the panels’ deformation will not have to be relegated to the second place.

KEYWORDS: Stained-Glass Window; Grisaille; Consolidation; Stone Wall; Laser-Scanning; Weathering

 

M. Camaiti, F. Fratini, S. Rescic, B. Sacchi

Proposta di intervento conservativo di reperti fossili del museo paleontologico di Montevarchi.

In this paper the problem of the consolidation of some fossil bones exposed in the Paleontologic Museum of Montevarchi (AR) is presented. These bones showed strong problems of conservation with powdering and detachment of fragments mainly due to salt crystallisation phenomena. Namely bone fragments, teeth and tusks of some species (Elephas, Rhinoceros, Equus, Bison) lived in the Upper Valdarno during the Pleistocene age have been studied. In order to propose suitable products for a conservative intervention, different consolidating materials both of inorganic (barium hydroxide) and organic (ammonium caseinate, polyvinyl acetate, a fluoro-elastomer) have been tested. The effectiveness of the treatments have been determined by visual inspection of cohesion and verifying thermo hygrometric ageing resistance, chromatic characteristics and UV stability.

Key-word: fossil bones, Elephas meridionalis, salt crystallisation, thermo-hygrometric conditions

 

C. Muscolino, C. Tedeschi, E. Carbonara

I manufatti musivi antichi su supporto di cemento armato: valutazione su alcune tendenze delle pratiche di consolidamento.

During the 20th century manifold ancient mosaic artworks were permanently changed by disputable restorations which envisaged the placing of the fragments that were extracted from the excavations on support made of reinforced concrete. In the last year these mosaics underwent restoration through an unreserved removal of the supports, which seems a fairly traumatic methodology alike the previous enticement on the concrete. Nowadays it is possible to have  awareness of the irreversibility of this operation, that is to be considered as historical, and the artwork has to be  acknowledged in its present aspect: sole exception is any threat to the preservation of the artwork. Below are explained  some experiences in the field of restoration ripen in the last years in Ravenna.

Key-Words: mosaics, removal support reinforced concrete, minimal intervention.

 

I. Bacchiocca , M. Bacchiocca , F. Ferrucci , A. Vastano

La messa in sicurezza di dipinti murali e stucchi Il caso dell’oratorio di Santa Croce di Urbino.

Without clear and careful preliminary planning, emergency operations intended for the recovery of architectonic decorations using facing and clamps can actually provoke additional damage. This study examines the post-seismic conservation intervention conducted at Santa Croce Oratory in Urbino. The complex was built around 1300 and houses a chapel dedicated to the Holy Thorn decorated entirely of stucco in 1568 by Pompilio Lanci. The first inspections following the earthquake revealed the extent of the damage: detachment, flaking, and cupping of the decorated surfaces due to structural deformations. Some plaster and stucco fragments had collapsed on the ground while others where threatening to fall. The conservation operations that aimed at the recovery of the chapel’s decoration begun in 2005 and were just recently completed. Due to the fragility of the materials, problems arose relating to reattachment and consolidation which demanded immediate resolution. The intervention was divided in two phases: the securing of all fragments at risk and the subsequent consolidation. In order to secure the fragments, a system using retention clamps was designed to immobilize the fragments. Of particular importance was the fact that it limited the application of facing (gauze strips and adhesive) and the use of traditional clamping, hence limiting potential damage to the materials. This intervention was a unique occasion for university research and experimentation. Current and past systems used for anchoring fragments in emergency recovery situations were analysed thoroughly using a wide range of case studies in order to identify each method’s advantages and disadvantages.

KEY-WORDS: wall paintings, stucco, seismic response, clamp, Urbino, Italy

 

L. Dei, F. Bandini, A. Felici, M. R. Lanfranchi, G. Lanterna, A. Macherelli, B. Salvadori

Pre-consolidation of pictorial layers in frescoes: the high performance of CSGI’s method based on nanolime evaluated by opd team in agnolo GADDI’s leggenda della vera Croce paintings, Santa Croce, Florence.

In the last decade the CSGI Consortium (National Center for Colloids and Surfaces) in Florence developed nanotechnologies for cultural heritage conservation. In particular, nanomaterials constituted of Ca(OH)2 (slaked lime) sub-micrometric particles dispersed in 2-propanol (iso-propylic alcohol) were found to be powerful as totally compatible frescoes consolidant.

The aim of the present contribution was to set up a kind of validation test by one of the leader teams in the world for wall paintings conservation, namely the Opificio delle Pietre Dure (OPD) équipe. The selected paintings were the monumental cycle La Leggenda della Vera Croce by Agnolo Gaddi (ca. 1350-1396) in the Santa Croce Basilica, Florence.

The conservation state of these paintings showed large regions of loss of adhesion-cohesion properties in the pictorial film and some tests of pre-consolidation by means of the traditional casein-lime water method did not give completely satisfactory results. The application of the CSGI technique, based on nanoparticle of lime dispersed in 2-propanol in the ultra-dilute regime (needing several consecutive applications), enabled to perform a very good cleaning procedure, due to the remarkable recovery of the adhesion-cohesion properties in the pictorial layers with respect to the casein method. The nanomaterial was also applied on parts previously treated with casein achieving good results even in these regions of the painting.

Details on the application steps and on the experimental results by scientific analysis are reported to spread the know how about this new technique and to ascertain the validity of the method.

Keywords: frescoes consolidation, nanolime, calcium hydroxide, nanomaterials.

 

A. Còccioli Mastroviti, C. Pezzani , G. Signani , B. Zilocchi

Il comportamento di consolidanti organici e inorganici. Due casi parmigiani a confronto: risultati del monitoraggio degli interventi condotti sulle facciate tardo-seicentesche di palazzo Piazza-Cordero e di Palazzo Boveri.

The painted façade of Building Piazza-Cordero, she has been submitted to a first intervention documented in 1930, with which big part of the decorations sacrificed him and was again object of restauration in 1987, following which, for the employment of stiffen and protective organic, the analyses chemical in 2000 and in 2006 they have noticed a serious picture, so much to be made impracticable, at least diffusedly, the 'restauration of the restauration.'  The façade to plasters of Building Boveri, restauration was submitted to in 1997, after one contemplated country of analysis chemical-petrografiche. The employment of the ethyl silicato as stiffen, have shown good behavior in the time, as it result from the analyses of control duct in 2007.

KEY-WORD: painted façade,  analyses of control, stiffen organic and inorganic, ethyl silicate.

 

P. Meloni, L. Massidda, D. Floris, G. Carcangiu, R. Quaresima, F. Paba

Stabilità dimensionale e termica di calcareniti trattate con silicati di etile.

This study concerns the influence on the main physico-mechanical characteristics of a calcarenite having high porosity and low strength exerted by four consolidants based on TEOS. The treatment  resulted very effective in improving mechanical properties and thermal stability. More complex was their effect on hygrometric properties: in fact a higher hygric swelling, due to the particular stratified structure of the xerogel produced after polimerization of TEOS, was observed, despite of a reduced water capillary absorption.

KEY-WORD: TEOS, xerogel, mechanical strength, porosity, hygrometric properties, thermal expansion.

 

C. Di Francesco, M. Ragozzino, B. Ferriani, M. Matteini, M. Realini, C. Conti, R. Mazzeo, E. Joseph, S. Prati

Esperienze innovative e conferme nei trattamenti a base di ossalati solubili su superfici lapidee e leghe metalliche: intervento e monitoraggio nel cantiere  del portale di Santa Maria delle Grazie a Milano.

The Lombard Direction for Cultural Heritage has promoted in 2006 on the portal of the Church of Santa Maria delle Grazie in Milan, a research and conservation yard with the aim to refine the existent conservative strategies and to develop new ones. The portal is mainly made by Candoglia marble, with a frescoed lunette above and a copper roofing. It presents a compromised state of conservation, mainly due to chemical attack by Milan atmosphere and to particulate deposition on the surface. On the basis of preliminary diagnostic studies and tests in situ, the employ of inorganic consolidant treatments has been chosen, and so ammonium oxalate has been applied on stone and sodium oxalate on copper roofing. Actually the monitoring of surfaces is in progress, in order detect the decay progression and define a conservative plan that allows to stop decay with as light as possible works.

KEYWORDS: ammonium oxalate, sodium oxalate, Candoglia marble, copper.

 

M. Favaro, F. Ossola, U. Russo, P. Tomasin, P.A. Vigato

Indicatori di degrado: uno strumento diagnostico per programmare la manutenzione dei materiali lapidei trattati con polimeri.

Aware of the requirements of professionals involved in conservation of stone monuments and the lack of scientific reliable data on efficiency over time of consolidation treatment with polymers, a research project has been developed by our Institute in collaboration with curators of building Heritage in Venice and the Paul Getty Conservation Institute focused on the development of a scientific strategy to investigate the effects of time on treated monuments. Artificial ageing of acrylic and silicone consolidants (Paraloid B72; Paraloid B67, a silicon-based product, Dri-film 104, and an acrylic-silicone mixture -Paraloid B72+ Dri-film 104- known as Bologna Cocktail) with light and salt solution have been monitored by physical and chemical measurements. The simulations allow the characterization of polymer deterioration processes and the identification of polymer decay markers. The detection of these degradation products on samples collected from several monuments treated in the past with the above polymers and naturally aged, validate the experimental results of artificial ageing and the hypotheses on polymer deterioration pathways. Examples are reported on data collected from treated surfaces of monuments in the Marciana area in Venice, of the Northern Portal of Udine Cathedral and wall paintings in Qusayr Amra, Jordan. The fully agreement between data collected from laboratory experiments and from naturally aged treated stone surfaces, enables the methodology to become diagnostic guidelines in the assessment of treatment efficiency of building heritage.

KEY-WORD consolidation assessment, polymer deterioration and removability, decay markers

 

L. Bassotto, A. Chiarelli, M. Pretelli, P. Pastorello, C. Tomasi, P. Pagnin, A. Abbate, M. Favaro, U. Casellato, C. Lugnani

La facciata lapidea della Chiesa di San Geremia a Venezia: tecniche di consolidamento dell’apparato architettonico decorativo danneggiato dal fuoco.

In 1998 the façade of San Geremia Church in Venice was deeply damaged by an arson, that has dramatically modified the architectural structure of the building (many decorative details went destroyed) and substantially changed the chemical and mechanical properties of the Istrian stone by which the monument is entirely made. The high temperature of the fire and the thermic shock due to high-pressure salty watering to estinguish the fire, had strong impact on the surface, both chemical and physical, with the result of production of calcium-oxide and hydroxide, and structural damages in the shape of large nets of cracks and fractures on the surface and even deep in the stone. This note is meant to present the methodological choices and the different philological implications imposed by the serious state of deterioration of the monument, which has forced the authors of the paper to verify step by step their strategies, materials and methodologies.

Key words: fire, Istrian stone, calcium-oxide, consolidation, inorganic binding

 

C. Accetta

Architettura moderna e consolidamento degli apparati decorativi: casi studio del fronte a mare a Palermo.

The present quest, through the investigation on the ground wants to emphasize the complexity of the interventions of consolidation of the architectural and decorative apparatuses of some modern buildings in the sea forehead in Palermo. Thanks to the comparison of the original sketches, of photo of epoch with the analyses and the investigations developed in situ, the technical specificities and realizzative of these architectures are understood and to the experimental and virtual verification of the possible solutions around their consolidation. In the following age immediately the second world war, the town administration tried to be realized a set of interventions that the wounds of the city cured provoked by the war destructions. In 1948 it began the construction of the longitudinal road to double neighboring roadway the port area among Porta Felice and the jail of the Ucciardone. In this optics of renovation it places the 1949 competition for the new Center of the Nautical Institute in the area of the destroyed hospital St. Bartholomew and the work realizations of the group BBPR, of the Center of the Newspaper of Sicily, along the Lincoln street, and of the Amoroso Building, insistent in the "Died Cassaro".

KEY-WORD: consolidation, modern buildings, concrete, chlorides, sea aerosol

 

F.Albani, M. Mittermair, M.Pescoller

La conservazione del fregio decorativo della Sichelburg di Falzes in Val Pusteria: problematiche metodologiche e tecniche.

The process of knowledge of the architecture and his contest was one of the essential requisite of  the methodology for the consolidation of a fifteenth-century fresco on a façade of a “Ansitz”, a house of  noble family. The conservation of stratifications is one of  target of the work.

KEY-WORD: consolidation, fifteenth-century fresco, process of knowledge, stratifications, South Tirol

 

K. Ambrogio, A. Conforti, R. Fabbri

Il consolidamento dei materiali moderni tra conservazione e sostituzione.  Un problema di restauro o di manutenzione ordinaria?

The present paper is a critical reflection on the surface consolidation regarding the materials used in modern buildings with an acknowledged value of cultural heritage. The acknowledgment of the historical and artistic value of a modern building does not simply entail the necessity of operating according to the common standards of building maintenance but also the necessity of applying the preservation criteria. Consequently, it is important to develop an in-depth theoretical analysis of the criteria and methodologies for the conservation of modern buildings, in particular as regards surface consolidation. The following materials were analysed: finished concrete, ceramic coatings and plaster surfaces containing asbestos.

The paper aims to understand whether the conservation principles applied to historic buildings are suitable for reproducible and serial materials which are close to our technologies.

KEY-WORD: finished concrete, ceramic coating, asbestos, preservation, maintenance

 

C. Benocci

Consolidare un materiale non adatto all’ambiente: i dodici mesi in arenaria di villa Sciarra a Roma, tra problemi e proposte di soluzioni.

The sculptures made in “arenaria” of  Villa Sciarra, called twelve months, of the XVIIIth century but used in the XXth century to decorate the garden, present a series of different operations where the restore didn’t respect  an different material from other stones used at Rome. Before the last restoration, in the 2005, only in the 1990-91 the director of works had tried to preserve the image of “arenaria”, with his colour and surface, without put on cement and other materials non appropriate. Nevertheless, the  “silicato di etile” used for restoration had conserved the last image, even if only the maintenance and the attention to the surface can guarantee a correct conservation of our sculptures.

KEY-WORD: Villa Sciarra – sculptures – “arenaria” – twelve months

 

M. Zampilli, G. Botticelli, P. Mariani, M.P. Topa

Macerata – Palazzo Buonaccorsi. Restauro strutturale e consolidamento degli intonaci dipinti: messa in sicurezza delle pitture murali mediante l’utilizzo del metodo della fermatura a punti con resina termoplastica.

Palazzo Buonaccorsi is certanly one of the most valuable nobiliary residence of Macerata both for the architectural form and the rich ornamental and pictorial apparatus which the most important are on the famous “Gallery of Aeneid” and on the first floor's others rooms.

Devoted to contain the town's museum of Macerata, from 2002 the palace is object of a complex and radical restoration.

The structural consolidation, according to the seismic improvement's standards provided by the technical normative, especially the regional normative, is been carried out by strictly conservative actions and by soft systems of reinforcement to restore the first functional character to the structural elements. Have been used building technologies taken from the local traditions, improved if necessary, but excluding technology and materials too stiff and invasive, frequently reason of the first structural behaviour's alterations of the different components.

In this contribution it is paid attention to preventive consolidation of the first floor's painted surfaces, necessary to minimize the increase's risk of the already unstable conditions of the supports during the structural actions on the walls.

The work is been carried out by specialized restorers using the point fastening method with thermoplastic resin.

KEY-WORD: Palazzo Buonaccorsi Macerata, restoration, consolidation painted surfaces, point fastening method.

 

G. Calcagno, A. Rava

L’evoluzione del consolidamento sottovuoto in sito applicato a manufatti di interesse storico artistico.

Concrete large sculptures and architectures exposed to outdoor environment undergo specific phenomena of decohesion, blister, detachment of fragments from the surface, chlorine and sulfate salts attack with related alterations of the composition of cement.

Water absorption increase the disruption with transportation of salts on the surface and growth of biological attack into the open pores.

Consolidation of the porous material has the aim of surface preservation and rehinforcement of the core of the sculpture in order to maintain a good static behavior to the work of art.

The risk of scarce  penetration of the consolidant allows delamination in layers loosing the most important parts of the sculpture with texture, hand and instrumentation traces.

In order to avoid insufficient penetration of the consolidant and to reach the solid substrate, vacuum systems were adopted since 1976, with good results for in-situ applications, increasing of 4-5 times the absorption of product.

Different vacuum systems are described with a recent active cycle application to a large modern sculpture of Tano Festa, “Finestra sul mare” at Fiumara d’Arte in Sicily.

KEY WORD: consolidation, concrete sculptures, maintenance, outdoor environment, vacuum system, micronized acrylic emulsion, Tano Festa.

 

F. Cassarino, S. Donesana, L.  Magni

Conservazione delle superfici architettoniche e decorative della facciata principale della chiesa di Santa Maria Maddalena in Montodine (CR).

N.D.

 

M. Baldan, C. Beltrami, R. Braggio, G. Frigo, A. Totolo, M. De Adamich, G. Castiglioni

Il consolidamento delle decorazioni della loggia Farinati in palazzo Bocca Trezza a Verona. Interventi diretti e modifica delle condizioni ambientali ai fini della conservazione.

Corte Bra Murari Palace, now Bocca Trezza, doubtless represents in Verona one of the most relevant examples of veronese Reinassance patrician architecture. Built towards the middle of XVI century it still houses a precious repertoire of fresco and plaster decorations. Tha loggia decoration at the ground floor by Paolo Farinati (end of XVI century) the object of this analysis, it is now in an advanced deterioration, the pathern and inquiry campaign led in cooperation with Sopraintendenza and local administrations, in view of a general preservation act, has revealed the dramatic situation in which lays Farinati’s work, besides new discoveries in the technical painting field and the materials used to produce it. The terrible conditions of the dry-paintings seems due to a radical change in the environmental conditions happened in the last century, following the demolition of a courtyard wing on which the loggia used face. This led to a sudden deterioration of its decorations which till the end of the XIX century were perfectly visible.

Therefore a conservative action proposal has been developed; its prior need is the consolidation of the preliminary layers and painting film.

KEY-WORD: Verona, Corte Bra Murari Palace, Paolo Farinati, dry-paintings.

 

G. Cavallo, G. Nicoli, M. Somaini

Il consolidamento degli intonaci della facciata principale della chiesa di San Fedele a Roveredo (Svizzera).

The manuscript shows the results coming from a multidisciplinary didactic laboratory held (3rd year students of Conservation and Restoration degree course) during the winter semester. The topic of this on field laboratory was the analysis and the conservation of the plasters which cover the main façade of St. Fedele Church at Roveredo (Switzerland).

The stratigraphic sequence exhibits three plasters belonging to three different periods: the first one is a lime-based mortar with the addition of silicatic sands used as rasa pietra plaster (13th-15th century); the second one is a early 17th century repair plaster used to close the original apse and to smooth the architectural surface; the last one is a 17th century plaster called schlämme (a thin fluid mortar) on which a graffito was incised.

The early 17th century plaster exhibits scarce adhesion to the support, superficial and structural   cracks.

The samples corresponding to each phase has been analyzed by optical microscopy; porosity has been measured before and after the treatment.

The consolidation of the early 17th century plaster has been carried out by ethyl silicate and meta-acryl silossane; structural cracks have been treated by injections of colloidal lime.

Key-words: consolidation, plaster, rasa pietra, (s)graffito, schlämme.

 

V. Daniele, E. Franzoni, R. Quaresima, F. Sandrolini, G. Taglieri, R. Volpe

Risultati preliminari di trattamenti conservativi a base di nanocalce su arenarie emiliane.

In the present work a nanolime, to be used in Cultural Heritage Conservation, is produced in order to evaluate its effectiveness on the conservation of some Italian sandstones.

Lime nanoparticles are  produced by a chemical precipitation process in supersaturated aqueous or alcoholic solutions of reactants. Then, they are characterised by transmission electron microscopy; hexagonal particles of dimension ranging from 50 to 600 nm are obtained. After that, the lime nanoparticles are applied on natural sandstones (Campolo and Grelio sandstones) and some tests are performed in order to estimate the consolidating effect of the treatment: “Scotch Tape Test”, “Surface abrasion test”, capillarity and imbibition tests, compressive strength and mercury intruded porosimetry.

Key-word: Calcium hydroxide, Consolidation, Lime, Nanoparticles, Protection, Sandstones

 

L. Di Bella, L. Lazzaroni

I chiostri di San Francesco a Bergamo: un restauro del restauro. Dal consolidamento degli affreschi negli anni trenta alle problematiche che si riscontrano oggi: proposte di intervento per l’attuale.

The former convent of San Francesco in Bergamo was built at the end of the XIII century and enlarged in the following two centuries. After its suppression in 1796, it was used as a jail till 1920.

During this phase, important tamperings of the ancient conventual structure are noticed; in 1938-39 a plan of restoration for its use as school was developed, attempting to restore as much as possible the pre-nineteenth-century situation.

At that time some pictorial cycles are discovered and restored. Several technical designs give us a clue about the performed works: Arturo Cividini restored the frescoes in the rests of the former church and in the cloisters. From the reports of the age we learn that the paintings “flake in an alarming way both on the surface of the color and of plaster”, and actions like “cement and casein injections, fixing of the color, cleaning and pictorial restoration” were taken. Nearly seventy years after this restoration these degradations are newly visible and an intervention of urgent consolidation is still necessary; in fact some parts of the frescoes in the cloisters are detached from the support, cracked and full of salts. These phenomena are partially due to the interventions performed from the thirty’s onwords because of the insufficient compatibility of the materials employed. Even today we are faced with the problem of how to consolidate frescoes and to stop the degradation, with the further challenge of coming to term with previous and the question of preserving them or not.

Keywords: “frescoes”, “cement”, “casein”, “injections”; “restoration of a previous restoration”, “salts”, “Arturo Cividini”

 

G. Castiglioni, C. Beltrami, M. Baldan, G. Frigo, A. Totolo, M. Nottegar, E. Vailati, R. Pasini

Il consolidamento degli apparati decorativi del giardino storico: la peschiera e le grotte artificiali di villa del Bene-Scopoli ad Avesa (Verona).

In the preservation of the historical gardens architectonic elements, issues related to these objects building characteristics are tackled: their nature, often intrinsically “ephemera”, that doesn’t expect the complete protection from environmental factors and the related deterioration, and their constant exposition to the atmospheric agents, that aggravate exponentially the conditions and finally, in case of the nymphaeums, the contemporaneous presence of very elaborate decorations and installations and “play of water” that maintain them in constant contact with very high humidity percentage, make extremely complex the operations turned to the conservation and strengthening of these astonishing manufactures. In the case of Villa del Bene – Scopoli nymphaeum in Avesa – realized during the early decades of the XVII century – the intervention highlighted a decorative method into the main so far unknown, concealed by a recent plaster; it is an extraordinary decoration in polychrome gravel totally uncommon in the Veneto area. The clearing operations from the coating and the following strengthening and preservation phases implied a series of problems which needed difficult solutions.

KEY-WORD: historical gardens, nymphaeum, grotto, “play of water”, polychrome gravel.

 

G. Frigo, A. Sandrini, G. Castiglioni, C. Beltrami

Il consolidamento degli apparati scultorei e architettonici del giardino di villa Rizzardi a Pojega di Negrar (Verona).

Among one of the most interesting and best preserved “green” Venetian architectures, the 18th century Rizzardi’s garden in Pojega di Negrar presents a splendid statuesque cycle comprising about 70 masterpieces. The rich and complex iconographic program spreads along an articulated route in the garden. It is animated from the “mythological presences” of the divinities beloved to the neoclassic culture of which the garden is an original mirror.

A large number of these statues are subject to enhanced degradation, leading to irreversible loss. Many turn out to be not only mutilated but also nearly unrecognizable due to the missing parts of the modelled crafts. The conservation’s main objective is to arrest the ongoing physical and structural degradation process. Therefore the causes of dangerous material falls are eliminated in the first place and the architectonic apparatus of such a unique and articulated complex is safeguarded.

KEY-WORD: Conservation, Pojega di Negrar, nummulitic limestone characterisation,

historic sculpture garden, diagnostic study, non destructive analysis

S. Gaggioli, G. Suardi

La chiesa di Santa Maria Assunta in Borgo: un’occasione per un proficuo confronto tra architetto e restauratore.

The Church of “Santa Maria Assunta in Borgo” underwent extensive analysis of materials, operational techniques and analysis of its conservational state before intervening. Moreover, during the analytical phase, graphic documentation was made of this important operation which looked at surface and depth consolidation (as well as surface scraping, cleaning, filling, painting additions, colour wash) which involved the plastered frescoed surfaces and not those indoors and outdoors. After finishing this work, the documentation, which was the result of architectural-renovation collaboration, was given to the commissioner and the controlling body in order to give a complete picture of a particular stage of the work; it was intended for whoever in future may need to intervene in other conservation projects.  The fifteenth century wooden ceiling, also underwent an appropriate scraping operation and surface consolidation of the painted goldcrests.

KEY-WORD: analytical phase - graphic documentation of operations - consolidation

 

A. Guerrini, S. Simonetti, R. Baratti Rava

Restauro della facciata Seicentesca in cotto a vista del palazzo Carignano in Torino.

The construction of Palazzo Carignano in Turin, commissioned by Savoia Carignano, was terminated in 1693. The original façade, in front of Carignano Theatre, was set up with hand made bricks especially made from Regio Parco kilns. After a few maintaining intervenctions during the 18th century, some greater conservative actions were carried out during the 19th century. Those interventions were particularly invasive because the building, enlarged, became the first Italian Parliament house, and it needed important structural strengthening. Conservative interventions were carried out in the 60’s and 80’s of the 20th century. Nowadays Palazzo Carignano hosts offices of Artistic Superintendence and the museum of Risorgimento. Last restoration, executed in 2001,  started with the construction of scaffoldings for a pilot test on the façade to understand how to develop and regulate next intervenctions. The intervention was carried out by Società Rava in collaboration with building company Zoppoli & Pulcher. Diagnostic tests were conducted from MAIP. Scientific surveys brought important results especially on bricks. All the operations of conservation, fillings, reinforcing and strengthening were made with inorganic materials.

KEY-WORD: handmade bricks, file research, First Italian Parliament, pilot construction site, diagnostic survey.

 

G. Lorenzini, C. Portosa

Un consolidamento degli anni settanta rivisto e corretto: i manufatti in stucco della Parrocchiale di Travagliato (BS).

This study shows the restoration works of the apse of Santi Pietro e Paolo’s Church in 2006. The surfaces had already been restored in the seventies with conservative methods based on the application of grout in order to stop the erosion  of the manufactured works and to reconstruct  parts of the mouldings. These applications turned out to be deleterious and caused new break-up of the material. This work describes the  technique of consolidation used in the last restoration. The materials used have suitable features with reference to the materials that make up the decorative and architectural  manufactured.

KEY-WORD: stucco, mouldings, erosion, break-up, consolidation

 

N. Santopuoli, S. A. Curuni, F. Maietti, S. Vanacore, L. Seccia, E. Troiani, V. Virgilli, D. De Vincenzo, E. Concina, L. Tapini

Il consolidamento degli apparati decorativi mediante dispositivi a memoria di forma: il progetto di ricerca sui dipinti murali di via dell’Abbondanza a Pompei.

The research project, started during the restoration site, recently concluded, has concerned the interventions of consolidation, conservation and restoration on some façades of ancient shops along via dell’Abbondanza (Regio IX, Insulae 7 and 11) in the archaeological site of Pompeii. These fronts are characterized by some of the most important mural paintings and electoral inscriptions.

A section of the research project has regarded the experimentation, still in progress, of new technological devices aimed at the restoration of mural paintings and based on Shape Memory Alloys (SMA) to work out consolidation problems otherwise solved by means of not-reversible or intrusive methodologies. One of the innovative applications of these devices concerns the movement of the polycarbonate sheets placed to protect the mural paintings.

The particular context of the research project is placed on the boundary between the excavated area and the still buried area; so, it has been particularly interesting to focus the research on the consolidation of decorations and mural paintings, also by means of the study of the interventions by Vittorio Spinazzola during the excavation works at the beginning of the XX century.  

Key-words: Consolidation, conservation, innovation, shape memory alloys, reversibility, methodological integration

M. Ottaviano

Recupero di dipiti murali celati alla vista. Basilica antica del Santuario di Oropa (Biella): navata centrale e cappella dei Lumini.

This Article describes the restoration methods applied to the brought to light XVIIth Century wall paintings in the Oropa's Basilica Antica, realized with both “fresco” and “secco” technique. After tre remeval of biodeteriorating agents and of soluble salt, the paintings were cosolidated; in order to evaluate if the consolidation was succesfully completed, the water absorption was measured directly on the painting surface thanks to a Karsten pipe. In order to remove deposited particle and cement layers was succesfully used the Jos-Rotec low pressure method, a specialized microabrasive cleaning treatment, which was established by the most recent studies to be one of the most succesful treatments for our purposes. Then, to give the paintings a unity that the fragmented condition no longer provided, the pictorial reintegration of lacunae was made using the tratteggio technique.

Key-Words:    Oropa Basilica Antica – tratteggio – wall paintings – paintings tecmniques -  Jos-Rotec low pressure method – lacunae – consolidation – microabrasive clening treatment

 

V. Pracchi

Mauro Pellicioli, ‘restauratore principe’: note sugli intereventi di consolidamento.

Practices used by restorers in the past are quite unknown today. The following notes concern Mauro Pellicioli’s interventions, especially those of consolidation of most relevant frescoes. Years gone by and the upgrade of operating techniques cause, in most cases, the denial, in terms both of knowledge and physical, of these restorations. The point is not to look nostalgically at old restorations, but to study techniques and attitudes to better understand how to behave today.

Key-Word: Pellicioli, old restorations, shellac, gum arabic, Brandi

 

V. Proietti

Il microconsolidamento delle superfici decorate del padiglione rinascimentale di villa Aldobrandini a Roma: una riflessione sui materiali e le metodologie adottate.

The decorative apparatus of the ancient pavilion of entrance in Villa Aldobrandini in Rome was settled and restored during the half of ninetys’, in the course of  the program of  appreciation of manufactures and of the garden. We can do some reflections about materials and tecniques which were used.

On that time it was possible either to use traditional materials and tecniques or to use industrial end prepacked products. This operation required people with a great tecnical – scientific experience and some chemical analysis to define the parameters which could be suited to the controlled employment of  the products.

The risk was rapresented by the uncontrolled use of new products to obtain an immediate aesthetic effect (consolidators, “tonachini”, paintings and so on) without a suited test to estimate the compatibility of the new materials with the present supports.

The different possibilities of restoration anno-unced the discussion among a work of  “improvement” and a work of adjustment, wich nowadays is occupying on a theoretical and practical level all the aspects of the restoration.

KEY-WORD: Villa Aldobrandini, the decorative apparatus, work of improvement, work of adjustment.  

 

M. Realini, C. Colombo, C. Conti, R. Negrotti, T. Poli, S. Baldis, R. Grazioli, M.R. Lanfranchi

Il consolidamento della facciata del palazzo del museo di piazza della Cittadella a Bergamo: monitoraggio delle applicazioni di ossalato di ammonio sulle superfici dipinte.

Conservation of external surfaces needs continuous actions because weathering processes often continue even on restored surfaces; for this reason it would be wise to carry out frequent “light” conservation works instead of a “sensational” one.

The monitoring of environmental parameters, of the progression of surface weathering process and of the durability and efficacy of surface treatments allows to define frequency and methods for planned conservation works.

Currently, CNR-ICVBC is carrying out many monitoring surveys based on non destructive methodologies characterised by low operating costs and good adaptability to different surfaces.

In this paper, the results of the application of an ammonium oxalate treatment on wall paintings are discussed. The behaviour of the treatment has been detected by non-destructive techniques, such as the measurement of colorimetric parameters (CIE L*a*b* system), of low pressure water absorption and micro-morphological observations of the surface.

KEY-WORDS: Wall paintings, Inorganic treatments, Ammonium oxalate, Monitoring.

 

B. Repezza, S. Franceschi, A.M. Lazzari, M. Lazzari, F. Rizzi, I. Benedet

L’apparato decorativo del campanile della Pieve di Gorto in Carnia: studi e conservazione.

During the study and the restoration of bell-tower of Gorto’s parish church of Santa Maria (in Ovaro, Carnia region), it has been discovered a series of at least three subsequent phases of polychrome decorations, located in the small suspended arches of the frame and in their intradoses. These decorations, characterized by four or six segments of white, red and ochre colour, helped in casting some light on the traditional decorations of Carnia bell-towers, revealing how they could have looked like. In fact, such ornaments have disappeared for the major part, by reason of the hard weather conditions of the region and of the heavy mechanical stresses due to bells movements.

As a consequence of this discovery, an extensive and detailed analysis has been carried out, which led to the project for the improvement of the whole bell-tower structural behaviour, conditio sine qua non for the preservation and reinforcement of the superior pictorial decorations, avoiding the use of paintworks.

KEY WORDS: bell-tower, suspended small arches, pictorial decorations, re-pasting

 

A. Fontanini, V. Ghezzi, D. Rancilio, L. Sala, B. Scala

Ancora sull’acqua di calce: il restauro della Cappella Cavalcabo’ nella chiesa di S.Agostino in Cremona a dieci anni dall’intervento.

Which has often raised aversion due to its applicative limitation and poor effect. However acqua di calce (special technique for consolidation) detained good resoluts especially in a project supported be the superintendency of cultural heritage of Brescia the restoring of the paintings. The restoring of the paintings in the chapel Cavalcabò in the church S. Agostino in Cremona (painting by Bonifacio Bembo and others). This chapel in one of the most important exemples of late gothic art, which survived the restoration during the 18th and 20th centuries mainly thanks to Guido Gregorietti’s work in 1951-1952. The project of the superintendency of cultural heritage in 1994-1995 of the chapel focused on the materials, the execution technique and the deterioration the aim was to restored the original plastering dating back to 15th century and to preserve the sing left by the following interventions. Acqua di calce has proved to be a fixing and consolidation agent thanks to its basic solution and the small quantite of calcium hydroxide. Moreover it is compatible with the original plastering and the restering materials. The invention was studied carefully because of technical difficulties like the consolidation of the internal parts of the plastering.  Realised on fragile materials without any pre-consolidation. The results are now discussed, more than 10 years later.

KEY-WORD: Compatibility, acqua di calce, fixing, historical intervention

 

V. Ghezzi, D. Rancilio, L. Sala, B. Scala

Le facciate policrome della chiesa di San Lorenzo a Bovegno (BS): storia dei consolidamenti di un apparato decorativo Cinquecentesco.

San Lorenzo’s church in Bovegno-Valtrompia in the only one which has maintenained its original multicoulored external plastering, mainly thanks to a series of works of maintenance end consolidation. This building lies betwen two small towns  (Irma and Magno) the two connonties contended fori t for a long time. Cater it was set aside end that soved it from renovation but not from neglect end deterioration, as it was abandoned in the XVIII century.

The building with its scratch-worksand painting frescos, was restored end preserved end the maintenance works took often dace in extremis, just before the coliapse.

Puring the last works from 2002 till 2005 we noticed G.B.Simonis’s contribution he was a brilliant and painter restored the façade in the 50s. The main chacteristics of its work were the technique used to strenghten. The original plastering and the decisions he took not only as restorer but also as artist, who pays attention to aestethic valves. The holes in the ornamental design were reintegrated with dull painteng end that was a good decision. While the plastering of other buildings in Val Trompia was ruined this essay gives some consideration about the inorganich consolidation and fixing system of the painted plasterings.    

KEY-WORD: graffito, ricostruzioni storiche, cemento, Bovegno

 

R. Scunza

Il restauro del plafone del teatro “Gabriello Chiabrera” di Savona.

On the morning of October 11th 1999, the acustic vault of the Teatro Gabriello Chiabrera in Savona, built in 1853, partially (40 mq)  collapsed. The architect and the restorer of the local department of the Italian Ministry of Culture (the Soprintendenza peri Beni Architettonici e per il Paesaggio della Liguria) during the inspection on the very day of the accident, gave the Fire Brigade precise instructions to collect the painted fragments of the collapsed vault to make a first catalogue.

The project for the restoration of the ceiling has been financed by the Italian Ministry of Culture (Ministero per i Beni e le Attività Culturali) and works undergone between 2004 and 2005: Fragments were reassembled with the help of a 1 to 1 photograph, then reenforced, linked and glued on a perspex structure with the same curve of the original existing vault. The whole ceiling has been reinforced with FRP bands (Fiber Reinforced Polymer) and finally the vault painted plaster has been restored.

KEY-WORD: Liguria - Savona – Theatre – Collapsed – Restoration – FRP – Vault

 

F. Tomba

L’apparato decorativo in terracotta del chiostro piccolo della Certosa di Pavia: conseguenze di un intervento sperimentale di consolidamento del dopoguerra.

The small cloister of Certosa in  Pavia is characterised by the presence of frizes and modelled terra cotta ornaments, with also some elements obtained by moulds and plasters. Starting from the 18th century there been problems of decay at terracotta frizes, caused by the differents between the matherials and position in the architecture. In 1953 Gino Chierici experimented a new surface treatment for the maintenance of terracotta, consisting in wax and turpentine. It was an experiment aiming at preservation that consisted by covering the surface of terracotta ornaments with a solution of wax and turpentine, after having brushed it. The practise was experimented many times for three years in the small cloister and the positive firming effects obtained without altering the terracotta colour were evident. From the autopsy test of the decay and alteration shape on the terracotta and the plaster coat the following alteration types occurred: grey deposit, organic film due to the maintenance, black deposit and surface efflorescence. At the same time the following decay types have been found: terracotta microfractures, splintering, breaking up and exfoliation, plaster microfractures, disappearing of the colour from the terracotta, painting fading on the plaster, lack of parts of terracotta and the plaster swelling. It’s possible to say that  the use above mentioned create a hydrophobe surface that not allows the passage of  salts in surface and create a lot of pressions that broke the layer whit wax and increase the decay.

KEY-WORD:   terracotta – consolidation – wax – hydrophobe – decay

 

V. Vaccaro

Uno scrigno di pietre dure. Il restauro dell’apparato decorativo delle Cappelle Medicee di Firenze.

The author illustrates the most recent issues of planning and executing the restoration of the marble and inlaid stone cladding at the Medici Chapels at San Lorenzo in Florence. Work started immediately after part of the interior panels collapsed revealing their complex fastening system. It took several years of research to complete the structural project, proceed with consolidation, and restore the marble components. New techniques employing traditional materials were purposely developed on site. Once again the results show how important it is to secure and coordinate different skills in the execution of complex restoration projects.

Key-word:  Medici Chapels. Marble. Restoration. Consolidation. Pozzolana lime.

 

P. Croveri, L. Dei, J. Cassar

Metodologie di consolidamento di superfici architettoniche interessate da sali solubili.  Il caso di studio delle fortificazioni Maltesi: valutazione dell’efficacia dei trattamenti e criticita’.

Soft limestones used as building materials in marine environment undergo fast and particular deterioration processes that seriously damage the historical and architectural cultural heritage of Mediterranean cities. The presence of soluble salts in masonry is one of  the most significant causes of degradation for highly porous stone and can limit the efficacy of adopted conservation treatments. Organic and inorganic consolidation methods, already evaluated in the laboratory on Globigerina Limestone (the local limestone of the Maltese islands) quarry samples, were tested on the deteriorated stone of local sea facing fortifications (Lower Barrakka Garden bastions). Evaluation of masonry salt content was performed by IC before treatments: chlorides, nitrates and sulphates were found in the substrates. Barium hydroxide, Ba(OH)2·8H2O, ammonium oxalate, (NH4)2·(COO)2·H2O, and a dispersion of calcium hydroxide, Ca(OH)2, in an alcoholic medium were tested and compared with ethyl silicate, acryl-siliconic resin and fluorinated products. The efficacy of these consolidation treatments was investigated by means of colorimetric measurement, the contact sponge method to assess water absorption by capillarity and the tape test to study surface re-aggregating properties. It was concluded that the dispersion of Ca(OH)2 was the most effective and compatible treatment; also effective was AmOx, which however resulted in an initial reddening of the treated surface

KEY-WORDS stone consolidation, soluble salts, Globigerina Limestone, treatment evaluation, calcium hydroxide dispersion, calcium oxalate, ethyl silicate, Malta

 

R. Giorgi, D. Chelazzi, P. Baglioni

Nanocalce per il consolidamento di pitture murali Maya in area sub-tropicale: un esempio di internazionalizzazione del know-how del CSGI.

Mexican cultural heritage is one of the richest in the world, and provides a huge source of information about Mesoamerican civilizations. Efforts for preservation, in the past years, included the use of acrylic and vinyl polymers as coatings for consolidation of wall paintings. Unfortunately, the strongly hot and humid climate of many Mexican regions increases the rate of degradation of these polymers, so that dramatic effects, such as flaking of surfaces and paint detachment, are produced in a short time. One possible alternative relies in the use of nanoparticles for the consolidation of the painted layers. This method grants a full physico-chemical compatibility between the restoration product and the substrate it is applied on. Dangerous drawbacks are thus avoided, and a full consolidation is gained. This paper reports last case-studies of paintings consolidation by using calcium hydroxide nanoparticles (developed by CSGI) in alcoholic dispersions. A new formulation for nanoparticles dispersion was tried, including extractives from Ramon tree (Brosimum Alicastrum), a local plant used by Maya as source of binder for pigments. By this way alterations of the mechanical resistance and hydrophobicity of the painted layers were avoided and a stable consolidation of the pigments was granted.

KEY-WORD: Mexican Cultural Heritage, wall paintings, consolidation, nanoparticles, Ramon, capillarity.

 

A. Moropoulou, E.T. Delegou, N.P. Avdelidis, E. Aggelakopoulou, M. Karoglou

Evaluation of consolidation interventions on Hagia Sophia mosaics using ndt techniques.

In this work the major interventions that took place for the consolidation of Hagia Sophia dome mosaics in 19th and 20th century are recorded. Moreover, the evaluation of these applied interventions is presented by the use of several Non Destructive Testing techniques like ultrasonics, ground penetrating radar, microwaves reflectometry, infrared thermography and fibre optics microscopy. The ND Testing & Evaluation that occurred in situ on characteristic dome areas compiled many data regarding the compatibility of old conservation interventions on Hagia Sophia mosaics, as well as significant information on cracks, detachment of mosaic bending mortars and tesserae, remaining dampness, and decay process on conservation plasters.

Keywords: mosaics, consolidation, Hagia Sophia, NDT  

 

S. Trucco, G. Villani, F. Badino

Ritrovare Porta Nuova. Studi, progetti e interventi di restauro della stazione torinese.

The projected intervention of conservative restoration springs up from the guess of keeping unchanged the original image of the building and, meanwhile, of working with techniques and methodologies reversible and not invading. The executive project also the fines a method expressed in a special specification (a manual) in order to give to the final workers a device easy to use. This device was thought to allow the workers of realising the intervention without the continuative help of the planners. We realized, after accurate valuation about the situation of the fronts, about the stone materials that have to remain in sight, and about the historical image of the building, every single phase of the intervention: the preparation, the structural consolidation, the repainting and the material restoration. The final result, about colours and materials, was gauged on the presence of stone materials that were in origin projected to prevail the noble front.

KEY-WORD:  Turin Porta Nuova railway station:  conservative revival

 

G. Berlingò,  G. Palandri

La certosa di Trisulti a Collepardo (FR) il restauro dei prospetti del monastero e della chiesa.

Within southern “Lazio” territory the “Trisulti” chartreuse in Collepardo (province of Frosinone - Italy) represents one of the most important examples of monastery founded at the beginning of the XIII century. At the present time it is a state property entrusted to the Cultural Heritage and Activities Ministry, even if is a concession to the Congregation of Cistercian “Casamari” Order; more over in  the “Trisulti” chartreuse is placed the homonymous National Library. The valorization, restoration and maintenance project of the architectural complex, formed by the buildings facing to the Trisulti chartreuse’s church square, has been undertaken by the “S.B.A.P.L.” of Rome, during 2004/2005 years and a restoration campaign relative to the monastery’s  and “San Bartolomeo” church’s façades, both integrant parts of the monumental whole, has been performed.

Key word: Chartreuse - Trisulti - Collepardo (FR) - Monastery - Church - S. Bartolomeo - Façades

 

J. Delgado Rodrigues, A. P. Ferreira Pinto, C. Paulos Nunes

Preparation of aged samples for testing stone treatments.

Some experimental protocols for producing artificially aged stone surfaces are presented. This type of surfaces is a good approximation to naturally decayed surfaces and therefore they are well suited to test consolidants and water repellents in controlled lab conditions. Marble and porous limestones are the object of this paper. Thermal shock was selected for ageing marble specimens, while salt crystallisation with sodium sulphate was used for producing decayed surfaces in the porous limestones.

Key-words: stone treatment/aged surfaces/thermal shock/salt crystallization/marble/porous limestone

 

E.Zendri, G.Biscontin, I.Nardini, M. Sgobbi

Indagini sulle variazioni microstrutturali di una pietra porosa trattata con consolidanti di diversa natura.

Lo studio prende in esame le variazioni di porosità valutate su campioni di pietra di Vicenza trattati con diversi consolidanti in solvente e in dispersione acquosa. Si esamina l’andamento del volume cumulativo e della distribuzione della porosità in relazione ad alcune caratteristiche dei prodotti applicati, in particolare alla viscosità ed alla dimensione delle particelle disperse. Quest’ultima caratteristica sembra influire in modo poco significativo sulla capacità di penetrare in profondità nel supporto, e solo parzialmente sulla capacità di penetrare nei pori di piccole dimensioni.

Key -Word: consolidation, porosity, porous stone.

 

R. Mazzari, U. Dainese, G. Driussi, G. Biscontin, M. Tonon, Z.Morabito

Comportamento di nanodispersi dispersi in acqua per il consolidamento di superfici architettoniche.