quaderni di assorestauro ARCHITECTURAL RESTORATION: A METHODOLOGICAL COMPARISON
YEAR05NR02 APRIL2016 4TH-9TH APRIL 2016 4 APRIL 8 APRIL ROMA MANTOVA 5 APRIL 8 APRIL PISA CREMONA 67- APRIL 9 APRIL FERRARA MILANO
Project financed by the Italian Institute for Foreign Commerce & Assorestauro In cooperation with Via Londonio 15 - 20154 Milano - Italy | Tel/Fax +39 02-3493.0653 | [email protected]
quaderni di assorestauro ARCHITECTURAL RESTORATION: A METHODOLOGICAL COMPARISON
YEAR05NR02 APRIL2016 4TH-9TH APRIL 2016 4 APRIL 8 APRIL ROMA MANTOVA 5 APRIL 8 APRIL PISA CREMONA 67- APRIL 9 APRIL FERRARA MILANO
Project financed by the Italian Institute for Foreign Commerce & Assorestauro In cooperation with
Quaderni di Assorestauro
Years 05 | Number 02 MARCH 2016
Edited by Andrea Grilletto Chiara Falcini Translation of the articles submitted in Italian language Raffaella Grasselli
Graphic Project
Blumorgana | Viviana Maria Lucia Volpini [email protected]
© copyright 2015 Assorestauro Servizi Srl
ISSN 2499-1864 (Print) - ISSN 2499-1503 (Online)
2 WWW.ASSORESTAURO.ORG WWW.ASSORESTAURO.ORG SPONSOR PRESENTATION
SPONSOR PRESENTATION
_ Presentation of “ICE Agency” 4 _ Presentation of “Assorestauro” 5
WORKSHOP SESSION
ROMA | 4th APRIL _ Restoration works in Rome - Tecnicon 6
INDEX _ media cleaning technolgy. The latest case history - Ibix 12 _ CRYPTOPORTICUS, THE DOMUS TIBERIANA ON THE PALATINE - SPC 16
PISA | 5th APRIL _ LASER REMOVAL OF BLACK CRUSTS FROM STONE: THE CASE STUDY OF PIAZZA DEI MIRACOLI IN PISA - EL.EN Group 28
FERRARA | 6-7th APRIL INSTITUTIONAL SESSION _ “salone del restauro in ferrara” CONFERENCES - ERMITAGE ROOM - pad 5 PLANNING RESTORATION: INTERNATIONALIZATION POLICIES IN THE RESTORATION SECTOR 32 SUSTAINABILITY OF HISTORICAL BUILDINGS: THE GBC HISTORICAL BUILDING PROTOCOL 34 _ CA’ FOSCARI EXISTING BUILDING OPERATIONAL & MAINTENANCE - GBC Italia 36
MANTOVA / CREMONA | 8th APRIL _ THE TOWN HALL BUILDING IN SAN BENEDETTO PO (MN) - Studio Berlucchi 40 _ ELECTROPHYSICAL DEHUMIDIFICATION OF MASONRY - Tecnova Group 46
MILANO | 9th APRIL _ The “Veneranda Fabbrica del Duomo” in Milan: a peculiar approach to conservation - Canali Associati 52
FOCUS ON... _ The Museum of “Opera del Duomo” in Florence. The architectural and installation project Adolfo Natalini - Guicciardini & Magni Architetti 59
INTERNATIONAL PROJECTS 66
CATEGORIES SPONSOR PRESENTATION INSTITUTIONAL SESSION WORKSHOP SESSION FOCUS ON... INTERNATIONAL PROJECTS 3 SPONSOR PRESENTATION
The Italian Trade Agency - ICE is the Government agency that supports the globalization of Italian firms, implementing the strategies of the Ministry of Economic Development. The Italian Trade Agency - ICE helps to develop, facilitate and promote Italian economic and trade relations with foreign countries, focusing on the needs of SME’s, their associa- tions and partnerships. The Italian Trade Agency - ICE sustains Italian firms in their internationalization processes, in the marketing of Italian goods and services while promoting the “Made In Italy’ image around the world, and it is directly involved in attracting foreign direct investments. The Italian Trade Agency - ICE provides information, support and consultancy to Italian companies on foreign markets, promoting and fostering exports and cooperation in all ar- eas – industry (consumer and capital goods), agricultural technology and agri-food, ser- vices, and training - with the aim of increasing and making more effective their presence on international markets. The Italian Trade Agency - ICE works closely with the Italian Regions, the network of the Italian Chambers of Commerce, business organizations and other public and private entities. The Italian Trade Agency - ICE headquarters is in Rome and its network of offices around the world act as “Trade Promotion Offices and/or Sections” of the Italian Embassies or Consulates.
associazione italiana per il restauro architettonico, artistico, urbano italian association for architecture, art and urban restoration elenco dei soci
MEMBER LIST
2016
WWW.ASSORESTAURO.ORG ® 4 ASSORESTAURO Via Londonio 15 - 20154 Milano - Italy | Tel/Fax +39 02-3493.0653 [email protected] | www.assorestauro.org SPONSOR PRESENTATION
Project coordinator: WHO IS ASSORESTAURO ? Andrea Griletto Established in 2005 as the first Italian association of manufacturers of materials, equip- ment and technology, suppliers of services and specialized companies, Assorestauro rep- resents the Italian sector of restoration and conservation of material heritage. To date, it is the sole association and a reference in the domestic and international market for anyone willing to start working in the conservation sector in Italy, to be intended in its broadest sense, that is, as a synthesis of the various disciplines involved, of the professional special- ists, of the available technology and of the growing business community. If examined as a whole, the sector accounts for a large market share and has a meaningful impact on tour- ism, industry and bioconstruction. WHAT ARE ASSORESTAURO’S GOALS? Assorestauro is the National Trade Association for the Restoration Sector, representing manufacturers of materials, equipment, technology, specialist companies, designers and suppliers of services for analyses, surveys and diffusion. The Association offers its mem- bers information, assistance, advice and training both directly and through its partners, with a view to building a consistent and unitary orientation to the different sectors of the restoration industry at national and international level. As a national association, Assorestauro is aimed at coordinating, protecting and promot- ing the interests of the restoration sector and it represents before the outer market, in Italy and abroad, the common positions for technical and economic issues, as well as image, by carrying out targeted activities in such relevant fields of the sector as information and communication, protection of common interests (economy, image, standards), research and development, promotion. WHAT DOES ASSORESTAURO DO ? Several activities aimed at promoting the professional skills in the restoration sector fall in associazione italiana per il restauro architettonico, artistico, urbano the scopes of the Association. They include diagnostic analysis, design and on site execu- italian association for architecture, art and urban restoration tion, producing technology and materials, as well as contributing technological innova- elenco tion, with the support of Institutions, Universities, Agencies for the protection of cultural dei soci heritage and ICE, the Agency for the internationalization and the promotion abroad of Italian businesses. This type of action includes both promotion in Italy (conferences and training seminars, trade exhibitions, courses and similar initiatives) and abroad (foreign MEMBER missions, training, b2b encounters, restoration sites), where member companies are in- LIST volved and offered the chance to study and penetrate foreign markets through projects co-sponsored by national and international bodies.
2016
® WWW.ASSORESTAURO.ORG ASSORESTAURO 5 Via Londonio 15 - 20154 Milano - Italy | Tel/Fax +39 02-3493.0653 [email protected] | www.assorestauro.org WORKSHOP SESSION
Restoration works in Rome april STATE OF CONSERVATION 4 The general conditions of the monument were critical, owed to several types of altera- tion. Climate changes and the microclimate affected by the presence of water and ambient ROMA aerosol generated an ideal habitat for microbiological and biological attack, especially on the cliff rocks. There were particularly thick limestone deposits on the areas affected by Paola Conti running, spurting and stagnating water, whose content in calcium is quite high in Rome. Luigia Gambino The fountain aerosol, rainfalls and winds are the main cause of decohesion and corrosion of the most exposed areas. TECNICON srl The heavily polluted urban environment caused layers of dust, topsoil and dirt to pile up on www.tecniconrestauro.it all semi-confined areas, resulting in the frequent recurrence of early black encrustations in the majority of the undercuts. Restoration by RTI – temporary association The great affluence of people and the improper use of the monument by visitors caused of companies - TREVINTRE damage to the accessible portions of the basin and cliff (engravings, graffitis, chewing- (CBC coop, TECNICON srl, ARA snc) gums).
SITE With the aim of allowing visitors to “enjoy the monument as a whole and complete arte- fact” during the works and to follow their progress, the following steps were adopted: _ install a totally transparent fence, complete with informative decals; _ erect the scaffolds at different times, so as to make a portion of the façade always vis- ible; in particular, the central portion of the façade was covered first, while the side por- tions were hidden only when the mid-portion scaffold was dismounted. No tarpaulins were used, so as to allow visitors to easily follow the works in progress;
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_ build an elevated walkway accessible from the fence, which runs through the basin like an “inner lane into the site”, so that tourists can approach the work areas. _ to preserve the long-established tradition of throwing coins into the fountain as a wish to return to Rome, a substitute basin was built in the middle portion. This way, tourists could keep throwing their coins above the fence and Caritas staff could keep collecting them.
To both sides of the fence, two large screens showed an uninterrupted sequence of pic- tures and films about the History of the fountain and of the square, including period prints reproducing the ancient versions of the fountain, also called Show of the Virgin Water, as well as odd events occurred within or near the fountain filmed and stored in the Historical Archives of Istituto Luce, and shots from famous movies having the renowned fountain as their backdrop.
RESTORATION OF TRAVERTINE AND MARBLE SURFACES - Removal of superficial incoherent deposits of dust, topsoil and bird droppings by means of brushes and hoover; _ disinfection of superficial weeds with weedkillers; _ disinfection by means of two applications of biocides on all surfaces; _ cleaning of all surfaces with compressed air sprayers at low pressure, with the help of large and small brushes and sponges; _ chemical spot cleaning aimed at removing all black encrustations from the undercuts. The affected areas were first padded with a weakly basic solution of cellulose fibre pulp and then any residual salts were rinsed off with demineralized water; _ mechanical cleaning of thick deposits (black encrustations) and of all limestone en- crustations from the cliff. This long and complex operation included a number of steps, with the use of different tools, such as hand-operated hammers and hardies, com- pressed air tools (hammers, vibrating tools and micro-air-abrasion equipment manu- factured by Ibix, model Trilogy 9 with HELIX helical vortex gun and almandine media of grain size 80-120 mesh), all of which ensured total protection of patinas;
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_ consolidation of the areas around any old heavy repara- tions, where decohesion and alveolization of travertine looked severe, which were removed by infills of micro- acrylic resins; _ machine-operated removal of any previous reparations that featured adhesion defects or poor aesthetic quality; _ gluing of restored portions of cement mortar and/or trav- ertine flakes with epoxy resin, sometimes with the addi- tion of threaded stainless steel or fibreglass pins; _ execution of deep reparations with Lafarge hydraulic lime mortars and pozzolana; _ execution of superficial reparations with carefully select- ed hydraulic mortars, after colour and grain size sampling; _ execution of micro reparations with slaked lime and mar- ble dust mortars; _ treatment of all copper foil elements (plants and trum- pets) by machine-operated cleaning of all surfaces, aimed at removing oxidation and residues of paint; cor- rosion-proof treatment, rehabilitation of colours with paints; _ final protection of all surfaces with a polysiloxane coat- ing.
STUCCO AND PLASTER SURFACES Detailed study, also based on research of historical records conducted in collaboration with the Site Manager and the Scientific Manager, and collection of numerous samples to choose the correct paint colours and to repair the degraded surfaces (use of imitation travertine of the same colour as travertine); _ application of acrylic resin primer on all surfaces; _ application of two layers of limestone paint in aqueous solution; _ finishing of all stucco surfaces by sponge application of a film of watercolours and acrylic resin in aqueous solution to mimic travertine; _ finishing of all plaster surfaces by sponge application of a film of watercolours and acrylic resin in aqueous solution to mimic travertine.
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Caterina Giovannini media cleaning technolgy. The latest case history
The cleaning process is a very delicate phase of the conservation work. In fact, it is an ir- reversible activity, which, if not carefully calibrated, can cause irreparable damages to the [email protected] www.ibix.it monument to be restored. Therefore, it is not possible to work with standard techniques, as every monument is a unique case on which it is necessary to calibrate the intervention mode specifically. This awareness is the root of the cleaning method proposed by IBIX; the structure of the REFERENCES equipment, their functions and adjustments, are specially designed to ensure the greatest Lazzarini L., Laurenzi Tabasso M., Il restauro della pietra, Utet 2010. control over the process, preserving the quality of the result. Alessandrini G., Feltrami C., Cordaro M., Effectiveness and potential damages are the two parameters that lead the cleaning result. Torraca G., Patine, pellicole e patinature, in Diagnosi e progetto The effects of the cleaning should therefore be evaluated considering the future outlook, in per la conservazione dei materiali order to monitor the cleaning effects in the long term. dell’architettura, De Luca Editore, 1998, Roma. The cleaning of the fountains, carried out partially with IBIX technologies, is an excellent UNI Beni Culturali, Materiali lapidei naturali ed artificiali. Descrizione della example for the intervention process described above. The importance of the monument forma di alterazione - Termini e - requires the utmost care in defining the operating mode and it is an outstanding test for definizioni, UNI Standard 11182:2006 the cleaning level guaranteed by IBIX equipment. Describing the stages of the fountain cleaning (those concerning the use of IBIX technolo- gies) is therefore a great way to explain the IBIX method. The intervention project consists of three phases: materials analysis, cleaning tests, results analysis. The correct execution of the sequence leads to the best cleaning process, which will be developed in the specific case of intervention. The cleaning of the fountain was carried out in order to remove the thick deposits of lime- Helix. Use of helical stone - which had been uplifting over the years - ensuring the utmost respect of the under- vortex gun helix lying marbles. for stone treatment Through various samplings, it is possible to define accurately the layer of material on which
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NANO Plus. IBIX microtip. It is a double The Nano Ibix functioning reveals its top (dry/wet) effectiveness with aero-abrasive the microtip Ibix; device, equipped this tool allows with a special the operator “quick connect” to work on the system and smallest details two easily with the maximum interchangeable comfort pistols, a standard
H2O and an Helix
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stopping the abrasion. The work is carried out at low pressure, starting from 0.2 bar. On the Trevi Fountain, the equipment were used in the dry mode (without water). The material selected for the intervention was the almandite exrafine 200 mesh. It consists of sub-an- gular shaped grains of mineral stone: it is an all-natural, chemically inert mineral abrasive containing no toxic metals, silica, ferrite and/or carcinogenic substances. It is a very tough and effective material, but at the same time it allows an optimum selectivity of the clean- ing process and enables to use very low operating pressure values. The media cleaning operations were performed with the HELIX gun, which is another im- portant parameter of intervention. The Patented HELIX® system consists in a special op- erating gun equipped with an original helical vortex nozzle design: this guarantees not only the maximum protection of the valuable surface patinas and historic coatings of precious artefacts, but also optimum worksite performance. This system exploits a combination of the Venturi effect, generated by the special conformation of the outlet cone, with a device that induces a helical rotary movement, in order to reduce considerably the air capacity re- quired to operate the machine. The wider tangential contact area generated by any same working pressure guarantees up to 30% more in productivity. HELIX is a tool created specifically for the IBIX intervention project. Its particular features perfectly fit with the scientific approach described above. The application gun increases the distance of the operator from the surface minimizing invasiveness without losing the evenness and effectiveness of the cleaning and avoiding that the operator needs to make constant corrections, which can result in the definitive loss of the layers to be conserved. Thanks to the IBIX technologies, it has been possible, in important historical and architec- tural contexts, to satisfy completely the project requirements.
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Giorgio Croci Alessandro Bozzetti CRYPTOPORTICUS, Studio Croci e Associati THE DOMUS TIBERIANA ON THE PALATINE
SPC s.r.l. INTRODUCTION STUDIO As reconstructed by Clemens Krause (see “Il Palatino area sacra sud-ovest e Domus PROGETTAZIONE Tiberiana”, Rome 1998), the Domus Tiberiana (the Palace of Tiberius) was bounded by E CONTROLLI the Clivus Victoriae to the north, by the so-called cryptoporticus of Emperor Nero to the east (still walkable today), by some premises partly open and partly closed towards the [email protected] www.spc-engineering.it area of the Magna Mater to the south, and by a retaining wall called Bastione Farnesiano to the west. In substance, at least its oldest part corresponds to the current perimeter of the Farnese Gardens on the Palatine Hill. During the present inspection, the sole site of the cryptoporticus will be visited, because works in the Domus Tiberiana have been completed.
THE DOMUS TIBERIANA ON THE PALATINE The large complex known as Domus Tiberiana is one of the most important on the Palatine and is made up by a succession of buildings which are badly inter-connected. Compared with the original configuration (Tiberius), in the period from Domitian to Hadrian (I -II cent. BC) there have been constant changes and expansions until reaching its current appearance (the part towards Via Nova) (Figure 1). The first phase, corresponding to the period of Nero, was characterised by a base comprising a casting of Roman concrete profiled with blocks of travertine. The phase under Domitian modified the Neronian scheme: the facade towards the Forum was reconstructed, completing the new front with a long loggia and transforming the Domus into a sort of offshoot of the great Palazzo which was built on the hilltop. Finally, Hadrian continued interventions: large arches were built which passed over the Clivus Victoriae, taking the front of the Palazzo up to Via Nova, with an architecturally spectacular result.
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At a later date, some tabernae were built on this front, probably also with the function of constituting a kind of buttress to contain the thrust of the wall, which was perhaps was originally intended to be internal and not a facade (Figure 2). The foundation ground of the original nucleus consisted of tuff rock, while the foundation layer towards the Roman Forum (Via Nova) consisted of silt-clay sediments from the Velabro, the course of which was diverted during construction of the Cloaca Maxima. The original structures (whose walls have thicknesses between 1.20 and 1.50 m) consisted of four levels:
1. Via Nova (23 m above sea level) 2. Clivus Victoriae (33 m above sea level, ground floor level) 3. Level 41 m above sea level (first floor) 4. Orti Farnesiani level 51 m above sea level (coverage) Most of the structures collapsed in ancient times and the remains were covered with soil, which permitted realisation of the gardens and terraces of the “Orti Farnesiani” on the upper level.
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INVESTIGATIONS AND INTERVENTIONS CARRIED OUT IN THE PAST In 1870, major excavations took place at the Roman Forum, and in 1900 the structures were uncovered: these excavations certainly negatively affected the stability of the structures facing the Forum. Around 1891, excavations were carried out in the area close to the Via Nova and on this occasion the walls of the orthogonal tabernae on Via Nova were restored. In 1960, the concrete brick floors covering the second level on the Clivus Victoriae were built, while in 1970 a first system of perpendicular metal tie-rods was put in place Via Nova to interconnect various detached walls. From 1985 for a period lasting around 10 years, a series of topographic measurements was carried. These measurements indicate that there are not only downward vertical movements (about 0.2-0.4 mm/year) with cyclic behaviour (probably of a seasonal climatic nature) but also a shift towards the Forum in a north-east direction with maximum values of 5 mm (1985-95). At the perimeter of the Domus towards the Forum, the surface layers have been eroded and covered by alluvial silt-clay deposits. In 2000, the “rigid” tie-rods were replaced by a system of new tie-rods (Diwidag bar type with diameter of 26 mm), anchored with leaf springs so as to have a deformable bond such as to maintain the substantially constant forces, independently of (or in any case little affected by) shifts induced by movements non-stabilised ground, as well as by thermal effects (Figures 3, 4, 5). A similar technique was applied to support the vaults of Palazzo Ducale in Genoa (Chap. ...) and for the vaults of the Basilica of St. Francis of Assisi (Chap. ...). In this way, it was possible to achieve a contrast against differential movements produced by soil sliding without, however, purporting to block them, thus avoiding dangerous concentrations of stresses. This intervention was associated with a monitoring system able to predict adverse developments and take timely corrective action, such as adjusting the tension in the chains, etc. Monitoring provided interesting data and, in particular, showed that the chains, as designed, undergo moderate cyclic variations due to thermal effects (of the order of 300 kg/sq. cm.). The relative displacements measured at the ends of the chains, which were slight, show that these do not significantly affect the stress state in the chains due to
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“flexible” anchorages made with the system of leaf springs (Figure 6). The most important lesions in the vast existing crack pattern, in particular those affecting the separation baffle between the 5th and the 6th spans, result in movement, even if with modest values.
DIAGNOSIS: STATE OF CONSERVATION, INSTABILITY, DEGRADATION The state of instability that characterises the area in question can be broadly divided into two categories: the first concerns the problems affecting the entire structure as a whole; the second is related to events such as injuries, cracks caused by localised crushing or degradation of materials, etc. Even if on the one hand these local phenomena do not prejudice the global safety margin of the structure, on the other hand they reduce durability and can represent a source of danger for persons. The signs of instability that are detectable today are difficult to interpret in relation to historical phases of construction, soil dissimilarities, the effects of excavations that have followed one another over time, previous reconstruction and reinforcement interventions, as well as the earthquakes that more than any other event have contributed to collapses and instability (among the strongest earthquakes, we recall those of 434, 801, 847, 1347 and 1703 which caused major damage to the Colosseum. The structures which survived collapses, to which degradation and neglect also contributed, are affected by diffuse lesions, detachments, misalignments and material degradation. The front of the Forum is today completely detached from the body behind. Lesions affect all the transverse walls up to the terrace at the level of the Orti Farnesiani. Vertical lesions cross the two paved levels of the Domus up to the level of the Orti. The foundations of the northern part towards the Forum, as noted above, are subject to worse behaviour than those behind; the presence of silt-clay layers which affect the east- facing zones more broadly than the west-facing zones, although of discrete mechanical characteristics, may have contributed to the instability that is detectable today, even though all the evidence suggests that earthquakes certainly played an essential role in collapses. Evaluation of the instability and forms of degradation that have affected the Domus is briefly described in the following paragraphs.
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Spine walls between Clivus Victoriae and Via Nova The entire area is characterised by a marked crack pattern of complex interpretation, which has also been the subject of monitoring for some periods (Figures 7). This crack pattern was already evident from the times of the excavations and demolitions in the 19th century, at which time some 16th century structures of the Farnese were removed, in part also close to the structures in question, along the Via Nova. There are deep lesions of isolated or branched detachment on the orthogonal dividing spine walls at Clivus Victoriae, which show a tendency to detachment between the fronts downstream and upstream of the area in question, which are visible both internally and externally. Such lesions are evident on the bases in Roman concrete of some buttressses on the front along the Via Nova: in some areas the width is greater at the bottom and tends to narrow further up.
Vaults of areas between Clivus Victoriae and Via Nova Even the vaults in concretion on the first level are affected by instability: most of these are visibly damaged by the fractures affecting the vertical walls (Figure 8).
Front on Via Nova and Tabernae The same front displays localised sections of heavily damaged and disaggregated Roman concrete such as to require the necessary provisional props of pipes and joints (Figure (Figure 5.8.10).). The party wall between the structures of the Clivus Victoriae and the tabernae on Via Nova is detached from the structures behind it, and also presents significant lack of material in the thickness (Figure 10). The front of the tabernae on Via Nova consists of three levels of walls parallel to the Via Nova which are disconnected between them. These walls are affected by structural instability, to which continuous infiltration of rainwater has contributed.
Clivus Victoriae Along the east-facing paved corridor (Clivus Victoriae), a major lesion can be seen at the
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base, which was athe lready visible during the excavation of the ‘70s; lately it has been brought to light, confirming the disconnection and a related movement of the entire front overlooking the Via Nova. Some pillars along the Clivus Victoriae show evident signs of crushing accented by detachment of the curtain from the original core through vertical lesions (Figure 11). Since the loads are small in relation to the resistant section, the cause is probably to be sought in the earthquakes or overload corresponding to differential sinking. On the other hand, some pillars on Clivus Victoriae present failures at the springer of the arches (Figure 12). The stretch of the east-facing vault is affected by a large crack pattern and is detached from the south wall.
North-west corner The corner area between the Via Nova and Via S. Teodoro has wide diagonal lesions that are probably due to the effect of earthquakes as well as settling of the soil that have occurred in the area (Figure 13 and Figure 14).
Structures upstream of Clivus Victoriae The structures upstream of Clivus Victoriae are affected by a conspicuous crack pattern that seems to confirm the tendency to disconnection of the entire north-west towards the Via Nova and the Forum: in fact, some lesions affect the orthogonal dividing walls at Clivus Victoriae and are mostly feedthroughs with a vertical progression, while others affect arches, vaults and lintels running parallel to the clivus (Figure 15).
STRENGTHENING INTERVENTIONS General aspects The interventions can be divided into global concerning the behaviour of the ensemble and local concerning individual elements. The global interventions essentially concern instability of the facade, and since it is currently neither necessary nor convenient to intervene on the foundations, the project is oriented towards recreating a structural continuity and containment of pressures, in addition to earthquakes. The system of
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shackling already in place creates a quite effective anchorage in the various walls parallel to the facade although it must be extended to structures upstream of Clivus Victoriae. The chaining must be supplemented by interventions to create a structural solidity between the various juxtaposed walls (by means of injections, insertion of connecting tie-rods, etc.). Local interventions essentially concern rebuilding of the vaults in order to raise the paved level and rearrange the terrace on the Orti Farnesiani, in addition to eliminating the old concrete brick floors. The coverage vaults on the second level towards Clivus Victoriae should be reconstructed in accordance with the ancient instructive techniques. Another intervention concerns the construction of some tabernae which also have the function of stiffening buttresses.
Ongoing interventions1 The first operation under way concerns the compensation of lesions in the spine walls and vaults, integrating them in correspondence with the failures. However, the core problem of the current project concerns seismic protection for a building that is intrinsically vulnerable due to the different quotas of strength of the foundations and the unevenness of the land involved. Seismic improvement is based on reconstitution of the walll “box” by compensating for the lesions, giving the walls a tensile strength by means of the insertion of some enchainments. The mounting system has shown a substantial stability of the phenomena for which it was planned to replace the existing chains, anchored to the flexible leaf springs with new enchainments partly inserted inside the masonry, and therefore not visible. Parallel enchainments have also been inserted to the front of the Via Nova with a view to creating a behaviour of the whole, eliminating local phenomena of tilting of the front of the header, not opposed by the vault that originally was to cover the environment concerned by the ramp. Reorganisation of the “heart” of the Tiberian Complex also includes reconstruction of the vaults and orientation of the terraces that cover the Domus complex. The new vaulted structures are in pieces of tuff mixed with mortar made of natural hydraulic lime of different thicknesses depending on the light cover.
1 The interventions are carried out by the Archaeological Superintendence of Rome under the guidance of Arch. M.G. Filetici
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Possible section of the galleries Early steps – the earth once filling the galleries up to the vault springer
CRYPTOPORTICUS
The area of the Cryptoporticus occupies the central portion of the Domus Tiberiana and features a roughly square arrangement. 16 This originally underground structure probably belonged to a network of galleries and pas- Detail of the two sages running through the foundations of the Domus and apparently connected to the brickworks perimeter area now visible (along the Clivius Victoriae to the north, below the Bastione Farnesiano to the west, etc.). After being used as farming fields and as a place of spoliation of ancient materials through- out the Middle Ages and the Renaissance period, the area was eventually buried below the gardens of the Farnese family, which were built in the mid 16th century by cardinal Ales- sandro Farnese, who wished to ideally reconnect with the ancient Rome of the Caesars (VV. AA. “Palatino area sacra sud ovest e Domus Tiberiana”, Rome 1998 Maria Antoni- etta Tomei, “Scavi francesi sul Palatino, le indagini di Pietro Rosa per Napoleone III”, Rome 1999).
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19. Survey of the cracks – assessment of damage 20. Survey of the cracks – assessment of damage 21. Survey of damage 22. First access
Regarding its construction, the whole vault is opus coementicium, but it was probably strengthened (or thoroughly reconstructed) back in Roman times with the erection of a 60cm-thick false wall rising up to the brick abutments (with an outer face made of hori- zontal joints and a conglomerate core of inert bricks) and finished on top with concrete conglomerate and tufa blocks. This sheeting was probably required after some collapse, but its static function is actually null in the brick portion, as demonstrated by in-situ tests carried out with flat jacks (figures 19 e 20). Some works were started in May 2006 to make a number of underground areas accessible again. The works were supervised by architect Giuseppe Morganti with the help of “Studio Croci e Associati” for the structural issues, of archeologist Ernesto Monaco for survey and constructional interpretation and, in the latest years, of archeologist Andrea Schiappelli for the excavations.
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SOUTHERN STRETCH Generally speaking, structural damage consists in some deep cracks of the conglomerate vaulted roof crossing the barrel vault diagonally from the south-eastern corner along the springers, from one basement window to the next. This caused the blocks to slide for some centimeters along an oblique plan and resulted in the fall of large amounts of materials in proximity of one of the abut- ments (figures 22-25). The concerned areas were eventually brought back to safe conditions with a number of works over the years. Synthetically speaking, the works consisted in installing a number of supporting structures in the southern gallery, as necessary while entirely reversible interventions to guarantee safety. At the same time, the continuity of the masonry was rebuilt by means of injections into the cracks.
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24. North-western corner. 25. Collapse of springers in the north-western corner. 26. Strenghtening masonry built by architect Martines in the north-western corner. 27. Construction of the underpinnings at different steps of the works.
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NORT-WESTERN CORNER A most severe damage to the structure consisted in subsidence of some portions, caused by the collapse of the caves or galleries found below, which in some cases resulted in the collapse of about 80cm-thick layers between the cap and the springer. Along the north- south gallery, subsidence generated the collapse of the whole springers. (figures 27-30). The cracks are found along the whole north-south longitudinal stretch of the gallery, al- though damage entities get progressively less severe southwards. Among various lesions, a horizontal crack is visible along the western wall of the vault, running along almost its whole length. In the north-western corner area, it was understood that, at least for the western portion, the cause of damage lied in the collapse of a number of galleries and sewage plants. For the sake of safety, the collapsed areas were excavated and a number of underpinnings were erected with a view to rehabilitate the capacity of transferring load from the built structures to the ground.
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LASER REMOVAL OF BLACK CRUSTS FROM STONE: april THE CASE STUDY OF PIAZZA DEI MIRACOLI IN PISA
5 A team of skilled restorers and scientists have been working for years at the conservation of magnificent monuments that adorn the Square of Miracles (Piazza dei Miracoli) in Pisa. PISA The first project involved the worldwide-famous Leaning Tower. In this case the surface conservation status was strongly influenced by the inclination of the tower, which accen- Alessandro Zanini tuates the deterioration linked to natural aging of the materials and to the conservation Laura Bartoli history of the Tower. Studies and tests had shown that the major conservation problems were related to erosion and disintegration of the stone and to the presence of gypsum and limestone deposits. In the area under the slope, however, the particles which are not washed away by the self- shielding effect of the Tower itself, are deposited and cause the formation of black crusts. Conservation Technologies Diffuse cracks, fractures and detachments of fragments are evidence of crushing phenom- Department ena related to the inclination suffered by columns and capitals. [email protected] The most appropriate methodologies for the restoration have been identified on the basis www.elengroup.com of the investigations results and direct experience gained in a project yard that took place in 2000, with the contribution of the European Union. Eleven cleaning systems, 5 products for consolidation, 18 types of mortars were considered appropriate and necessary for the conservative intervention. Among the cleaning meth- ods, laser technology has been used successfully on the most damaged and exfoliated
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parts of the capitals for a gradual and safe removal of the black crusts without damaging the fragile substrate affected by cracks and gaps. Subsequently, the efforts of restorers focused on the preservation of the Cathedral. The last actual restoration of the monumental Cathedral, aside from the renovated façade for the Jubilee of 2000, dates back to the forties. A total restoration using advanced tech- nologies has been carried out. The first phase started in 2013 and ended up in 2015. The intervention started with a pilot project that healed a portion of the basin apse next to the transept of the Blessed Sacrament, then the restoration has been extended to the en- tire building which was in a state of high degradation characterized by biological attack and aggressive deposits, moreover black crusts and missing parts were found in the most decorated parts. These decorated parts (such as capitals) were all laser cleaned: the laser allowed the fast and safe removal of the thick black crust even from very modelled and curled decorations. The conservation problem in Pisa shows a clear example of the potentials of laser cleaning of stone. Lasers are nowadays seen as an additional instrument in the restorer’s toolbox. The main advantages of the use of lasers for the removal of black crusts from stone sur- faces are the following: no chemical species are required, the removal is very progressive so the restorer can decide the most appropriate level of cleaning, the cleaning is extremely precise because it involves only the area lit by the laser beam, which may be accurately limited as needed and last, but not least, if the laser is properly set, the process of cleaning automatically stops after the black crust removal because of the different reflectivity of the marble. After the pioneering work made by J. Asmus since 1970(1) (2) it has been shown
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by many studies (3) (4) that the Nd:YAG lasers offer the best compromise of selectivity and efficiency, being also rugged enough to work in difficult conditions such as open air or on scaffoldings. It has been proven that, beside the wavelength, the pulse duration is a cru- cial parameter for the optimization of the laser-stone interaction (5) (6). In the 90s a novel fiber-coupled Nd:YAG laser emitting pulses of 20µs, the so-called Short Free Running (SFR) temporal regime was introduced (7): this pulse duration, intermediate between the very short pulses (Q-switched regime, 10ns pulse duration) and very long pulses (Free running regime, 500µs pulse duration) was proved to provide unique gradualness and self-termination performances without damaging the stone substrate. This new SFR system was massively applied in restoration works of historical façades (8) (9) (10), ancient archaeological artworks (11) and stone reliefs (12) and Renaissance masterpieces such as the Prophet Abacuc by Donatello, the Fonte Gaia in Siena by Jacopo della Quercia, panels of the Giotto’s campanile in Florence and many other works. Most of the discussion, which accompanied the early stage of laser cleaning application, concerning possible side ef- fects due to laser irradiation of stones gradually reduced along the last decades thanks to systematic phenomenological and process-optimization studies that allowed to de- fine the operative fluence ranges ensuring effective discrimination between the layer to be removed and the substrate underneath to be uncovered (13). Furthermore, also the well-known problem of the yellowish appearance associated with Q-switching Nd:YAG cleaning of white stones (14) has been thoroughly investigated (15) (16) and practically solved. Some studies showed that this chromatic appearance was due
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to the partial removal of pigmented stratifications and/or to penetration of organic sub- stances through the outer layer of the stone. The removal of alteration layers from stones can often be achieved by using the laser only but in many cases the combination of the laser with traditional chemical or mechanical methods may be needed or preferable. The laser cleaning of the capitals of both the Lean- ing Tower and the Cathedral in Pisa was performed after the imbibition of the black crust in water for one night to soften the crust itself and make it easier to be removed by laser. In general, the efficiency of the laser removal is increased if the surface to be treated is wet with water before the irradiation. This wetting produces two main effects: a refractive and an ablative one. The refractive effect leads to a decrease of reflectance for the wet sample, due to a change in the refractive index between the material and the air (less radiation is reflected away). Moreover, the voids in the material are filled and this causes a reduction of the optical diffusion effect (higher penetration). On the other side, for the ablative -ef fect the fast vaporization of water penetrating into microcracks speeds up the material ejection. In conclusion, the conservation of the monuments in Piazza dei Miracoli in Pisa represented one of the last successful application of laser cleaning for the removal of black crusts from stone substrates. The optimization of the main laser parameters, supported by rigorous scientific investigations, is of crucial importance to spread the use of this innovative tech- nique in the world of conservation of Cultural Heritage.
REFERENCES 9. Calcagno G., Koller M., Nimmrichter J. 1997, Restauratoren Blatter 39. 1. Asmus, J. F. 1978, Technol.Conserv. 3, p. 14. 10. Calcagno G., Pummer E., Koller M. 2000, J. Cult. Heritage 1, p. 111. 2. Asmus, J.F. 1986, IEEE Circuits Devices Mag. 2, p. 6. 11. Pouli P., Frantzkinaki K. et al. s.l. : Springer, 2005. LACONA V Proceedings. pp. 3. Cooper MI, Emmony DC, Larson JH. 1992, Proceedings of the Seventh Interna- 333-340. tional Congress on Deterioration and Conservation of Stone, Lisbon, p. 1307. 12. AE, Delgado Rodrigues J. Charola. Jeronimos Monastery, the conservation 4. Liu K, Garmire E. 1995, Appl. Opt. 34, p. 4409. intervention. Lisboa : Cadernos IPPAR, 2006, pp. 199-206. 5. Siano S., Salimbeni R.,. 2001, Stud. Conserv. 46, pp. 269-281. 13. Siano S., Agresti J., Cacciari I. et al. 2011, Appl. Phys A. 6. Salimbeni R., Pini R., Siano S. 2000, J. Cult. Heritage 4, pp. 72-76. 14. Vergès Belmin V., Dignard C. 2003, J. Cult. Heritage 4, p. 238. 7. Margheri F, Modi S., Masotti L. et al. 2000, J. Cult. Heritage 1, pp. 119-123. 15. Klein S., et al. 2001, Appl. Surf. Sci. 171, p. 243. 8. Bromblet P., Labourè M., Orial G. 2003, J. Cult. Heritage 4, p. 17S. 16. Siano S., et al. 2008, Laser Phys 18, p. 27.
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INSTITUTIONAL SESSION 67- APRIL FERRARA
ORGANIZED BY IN COOPERATION WITH
THURSDAY 7TH APRIL 2016 | FROM 9.30 AM TO 1.10 PM | ERMITAGE ROOM | PAD 5
VALENZA FORMATIVA: SEMINARIO A RILASCIO CREDITI FORMATIVI PLANNING RESTORATION: PER ARCHITETTI E INGEGNERI o e e il Res o oli ic e di in e n ion li ione e il se o e es o
INTERNATIONALIZATION POLICIES THURSDAY APRIL 2016 IN THE RESTORATION SECTOR 7 09:30 - 13:30
Chairman: Nicola Berlucchi ABSTRACT. Italy has historically spread worldwide its peculiar theories of restoration and con- servation effectively guiding the international approach for preserving Cultural Heritage. Italy has also exported its craftsmen, artists, architects and engineers over time to deal with the most important monuments all over the World. The Italian Restoration sector, substantially developed into an organic “industrial” system af- ter the new Millennium, seems now ready to create its own strategies for promoting its model, materials, technologies, enterprises, specialized design offices and service societies worldwide. The conference aims to present some examples of international cooperation, focused on the restoration design area, through the Internationalization Policies supported by the Italian Min- istry of Economic Development (MISE) by its agency ICE-Italian Trade Promotion Agency and through other models of international cooperation and autonomous experiences. Some example of international projects carried out by ICE Agency and Assorestauro from 2013 to 2016 are presented together with the future target Countries. Delegates from North America, South America, Iran and Lebanon has been invited to present the opportunities of increasing the involvement of the Italian enterprises in their own markets.
32 WWW.ASSORESTAURO.ORG INSTITUTIONAL SESSION
PAD 4 STAND B12-D13 CONFERENCES AT THE EXHIBITION OF FERRARA
9.00–9.30 Registration for credits of professional education with Assorestauro staff 9.30–10.20 INTERNATIONALIZATION POLICIES ICE – Agency for the internationalization of Italian Alessandra Capobianco ICE businesses: Supporting internationalization in the TH restoration sector THURSDAY 7 APRIL 2016 | FROM 9.30 AM TO 1.10 PM | ERMITAGE ROOM | PAD 5 Emilia-Romagna Go Global 2016-2020. The policies of Ruben Sacerdoti Regione Emilia Romagna support to business internationalization and the case of the restoration sector Giorgio Malfatti di Monte Tretto IILA IILA cooperation initiatives in the restoration sector Alessandro Zanini Assorestauro Cooperation between associations
Nicola Berlucchi Assorestauro International planning experiences INTERNATIONALIZATION PROJECTS 2014-2016 10.20-10.35 Tatiana Vyatchanina CNRPM RUSSIA: The Restoration School in Moscow
10.35-10.50 TURKEY: MED ART Turkey-Italy International project Olcay Aydemir VGM and the restoration of Sheik Sulayman Mosque 10.50-11.05 Nelys Garcia OHC CUBA: Italy-Cuba Cooperation in the restoration sector
11.05-11.15 Coffee Break THE RESTORATION SECTOR IN THE TARGET COUNTRIES. OVERVIEW BY THE DELEGATES INVITED TO JOIN ICE – ASSORESTAURO INTERNATIONAL WORKSHOP 11.15-11.30 AIA, LEED AP Kitty Vieth NORTH AMERICA Principal, Architectural Resources Group 11.30-11.45 Council Member PRIE (Plan Rector de Intervenciones Guillermo Garcia SOUTH AMERICA Edilicias), National Congress Architect & Conservator and Deputy Chief (Vice 11.45-12.00 Hassan Talebian IRAN President) of Iran Cultural Heritage, Tourism and Handicrafts organization 12.00-12.15 Randa Kawekji LEBANON Architect Restorer – Responsible of DGA offive in Tripoli EXAMPLES OF INTERNATIONALIZATION 12.15-12.30 Marco Martuscelli Planach Planning in Lebanon
12.30-12.45 International experiences of structural engineering and Alessandro Bozzetti SPC site management 12.45-1.00 pm International experiences in National Vulnerability Pasquale Crisci AIRES INGEGNERIA Assessment and Pilot Retrofitting in Buthan Signature at exit for CPE
WWW.ASSORESTAURO.ORG 33
INSTITUTIONAL SESSION 67- APRIL FERRARA
ORGANIZED BY IN COOPERATION WITH
THURSDAY 7TH APRIL 2016 | FROM 9.30 AM TO 1.10 PM | ERMITAGE ROOM | PAD 5
VALENZA FORMATIVA: SEMINARIO A RILASCIO CREDITI FORMATIVI SUSTAINABILITY OF HISTORICAL PER ARCHITETTI E INGEGNERI
Il o ocollo B is o ic B ildin BUILDINGS: THE GBC HISTORICAL 2016 14:30 - 17:50 THURSDAY 7 BUILDING PROTOCOL APRIL
Chairman: Marcello Balzani
ABSTRACT.The conference aims to study the large-scale topic of sustainability particularly fo- cused on historical buildings, a particular framework in which the energy efficiency approach needs to be harmonized with the historical assets and preservation priorities which characterize the restoration area. Furthermore, the conference aims to introduce the requalification issues as a clear opportunity for enhancing the efficacy of the preservation policies for the reuse of the historical building heritage. Within this complex framework, The Green Building Council Italy is elaborating a specific rating system for the certification of historical buildings. The GBC Historic Building, the name used for the new rating system, aims to tackle this specific area starting from the peculiar Italian sector of the restoration of historical architectures, based on the most well-framed regulations and the wider diffused Cultural Heritage in the World. Specific Case Studies, related to the application of international standards, will be introduced: LEED EBOM protocol, developed by the American Green Building Council especially for living buildings and focused on the sustainability in terms of management and maintenance and LEED C&S protocol, which deals with the building envelope in terms of heating and cooling sys- tems, in addition to the GBC Historic Building protocol
34 WWW.ASSORESTAURO.ORG INSTITUTIONAL SESSION
PAD 4 STAND B12-D13 CONFERENCES AT THE EXHIBITION OF FERRARA
2.00-2.20 PM Registration for credits of professional education with Assorestauro staff 2.20-2.50 PM GBC HISTORICAL BUILDING PROTOCOL: INTRODUCTION Alessandro Zanini Assorestauro Cooperation between associations Alessandro Gasparini INARSIND Seismic mitigation and sustainability Marco Caffi GBC Italia Sustainability of built environments Marcello Balzani Università di Ferrara Introduction to the conference topics THEORETICAL OVERVIEW 2.50-3.10 PM Nicola Berlucchi Freelance advisor How to adjust ancient buildings to modern requirements SOME EXPERIENCES OF IMPLEMENTATION OF THE LEED PROTOCOL 3.10-3.30 PM The implementation of LEED EBOM Protocol Alberto Ballardini Habitech in Ca’ Foscari, Venice 3.30-3.50 PM The sustainable rehabilitation of Palazzo Ricordi in Sandro Favero F&M Engineering Milan and the implementation of LEED C&S Protocol 3.50-4.10 PM Coffee Break NEW TOOLS AND GUIDELINES FOR THE REGENERATION OF HISTORICAL BUILDINGS 4.10-4.30 PM Livio De Santoli AICARR Energy efficiency of historical buildings
4.30-5.00 PM Carlotta Cocco EVO3 GBC Historical Building Protocol: integrating Marco Zuppiroli Università di Ferrara sustainability and restoration Giuseppe Bonfante Onleco Sustainable regeneration of historical buildings: a case 5.00-5.20 PM Chiara Bonvicini Onleco study of implementation of GBC Historical Building Giovanni Stefania SECAP Protocol 5.20-5.30 PM Marcello Balzani Università di Ferrara Conclusion Signature at exit for CPE 5.30-6.00 PM FINAL GREETINGS BY ASSORESTAURO At the end of the conference, Assorestauro invites all the participants to its booth for a farewell drink
VALENZA FORMATIVA: VALENZA FORMATIVA: SEMINARIO A RILASCIO CREDITI FORMATIVI SEMINARIO A RILASCIO CREDITI FORMATIVI PER ARCHITETTI E INGEGNERI PER ARCHITETTI E INGEGNERI