ULUSLARARASI İSTANBUL TARİHİ Y ARlMADA SEMPOZYUMU 2013 1

INTERNATIONAL ISTANBUL HISTORİCAL PENINSULA SYMPOSIUM 2013

EDİTÖR 1 EDITüR

Doç. Dr. Nazlı Peralı Alcıncı

İSTYAM

Yıldız Teknik Üniversitesi

İstanbul Tarihi Yarımada Uygulama ve Araştırma Merkezi 1 . .

Yıldız Technical University Is tanbul Histoncal Peninsula Application and Research Centre

İletişim 1 Contact

Haci Ev baddin Caddesi No:80 Yedikule fatih İstanbul

Tei&Faks: 0212 5882114

istyam@yildiz.edu.tr

www.istyam.yildiz.edu.tr

ULUSLARARASI İSTANBUL TARİHİ YARIMADA SEMPOZYUMU 2013 İstanbul Tarihi Yarımada Uygulama ve Araştırma Merkezi

BULGAR ORTODOKS KİLİSESi "SVETİ STEFAN". PASLANMIŞ DEMİR YAPILARlN OPERASYONEL DAY ANIKLIGI ARTTIRMA TEKNOLOJİSİ

Blagovesta lvanova, Higlıer School of Civil Engineering Luben Karavelov, Faculty of Architecture, bg_ fıueart@abv. bg

.... Özet

Nikolay Barovski, Institute of Metal Science, Equipment and Technology - BAS, barovsky@gmail.com

Raporda, Türkiye Cumhuriyeti bir mimari anıt olan İstanbul, Bulgar Ortodoks Kilisesi "Sveti Stefan"'nın restorasyonuyla ilgili bir araştırma projesinin sonuçlan sunulmaktadır. Proje, Bulgar mekanik ve mimarlık uzmanlan tarafından uygulanmış olup ana sonuçlan Bulgaristan Devlet Arşivinde muhafaza olan belgelerin analizine dayanmaktadİr. Projede modem bilgilerle yanısıra kilisenin son restorasyon öncesindeki durumu temel olarak alınmaktadır. Sözü geçen restorasyon henüz tamamlanmarruştır. Bu raporun amacı, kilisenin eski pastanmış çelik konstrüksiyonunun dayanıklılığını arttıran

teknolojinin avantajlann~ göstermektir. Kalsiyum sülfonat kaplamalann korozyonu önleyen yöntemin uygulanması ile pasianmış çelik yapılann ömrü uzatılabilmektedir. Teknoloji temizdir, agresif kimyasal maddeler kullanılmamaktadır. Bu sistem, tam bir renk yelpazesini içermektedir. Renkler aşınınaya karşı dirençli ve dış etkenlerle değiştirmez.

Anahtar Kelime/er: Bulgar Ortodoks kilisesi St Stefan, korozyon, prefabrik çelik, dölane demir, pas

THE BULGARIAN ST. STEFAN CHURCH IN ISTANBUL. TECHNOLOGY FOR INCRESING OF SERVICE LIFE OF RUSTED IRON WORKS

Abstract The report presents a research project for the preservation of the Bulgarian Orthodox Church St. Stefan in Istanbul which is the monument ofarchitecture ofRepublic ofTurkey. The project was made by Bulgarian specialists of architecture and mechanics. The main result of the report is a thorough analysis of the constructive and artistic similarities of the temple based on architectural projects and descriptionş, preserved in Bulgarian State archive. They are a base for the studying of the histoncal state of the ·churcb duıing the ages and the devetoping of contemporary knowledge of i ts condition, before it last restcration whicl} has not yet fınished. The ai m of the paper is to show the advantages of a technology improving the durability of old rusted steel structures. Using a "stop corrosion" method based on calcium sulfonate covers it is proposed to increase the service life of rusted steel elements. The technology is ecological without chemically aggressive agents. All colors are available. The colors are extremely faded and chalk resİstant and have superior color retention.

Key words: Bulgarian Orthodox church St. Stefan, corrosion, prefabricated stee/, cast iron, rust

Introduction

The Bulgarian church St.Stefan in Istanbul, also known as the "iron church", is the most signi:ficant Bulgarian monument of architecture in Turkey. According to arehive documents, in ı 898, when it was inaugurated, its construction and its furnishing were estimated at about l million gold levs to the Bulgarian state. The unique steel construction witb interior and exterior steel claddings placed it among the few buildings of this type, mainly designed by Gustav Eiffel. Some of the most famous buildings of this type are the church of God in Dinaburg, Lithuania; the church of St. Marco in Arija, C hile; the church of St. Barbara in San ta Rosalia in the Gulf of Califomia, Mexico; the churcb of St. Sebastian in Manila, the Phillipines, and the temple in Grecia, Costa Rica. All of them were built in ı 9c. The St. Stefan church is operative temple. lt has a board, w hi ch is registered as a foundation under the laws of the Republic of Turkey and is taking care of it. From Bulgaria i ts fınancing and i ts preservation are assigned to the Department of Religions at the Council of Mini s ters and the National

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Institute of iınmovable cultural heritage. It is currently a monuınent of the architecture of the Republic of Turkey and by the bilateral cultural agreements its preservation is shared between the two countıies.

1. The Current State of The Construction of The Church.

The current s ta te of the monument b_rings up various questions. They are becoming a problem for the Bulgarian society, because the church is signifıcant for the Bulgarian histarical development in 19 c. In the last decade, there were numerous fundraising campaigns for donations (Parvanova, M. 201 1) for the preservation of the temple, but none of them resulted in a radical change, because they were insufficient. The Bulgarian cultural institutions did their own studies, which were not highligbted in the cultural area and in the area of the experts. The decisive activities are objective of the Turkish institutions. The problems looks like as a closed in a triangular. Their decisions have not the connection between them. For many years the monument of architecture has not been attractive for the tourists because i ts steel frame iscovered with active1y devetoping corrosion.

The la test investment for the preservation of the unique monument'was done in 20 ll when -the Grand Istanbul Municipality decided to start out a repair work. It began in September, but was suspended due to errors in the technology of. the preservation of the monument (Remontat na carkvata, 2012; Prikluchi nabiraneto, 2012). The price for the repair works was estimated at 2,5 million euro. It is lmow that the restaration work staıted with mechanical cleaning of the corrosion on the metal plates on the external facades (Dnevnik, 2012). After the removal of the plates, a large degree of corrosion was found in the steel construction of the temple (BNT, 2012; Agencia "Fokus", 2012). This isn't surprising, s ince we lmow the history of the preservation of the temple.

A sirnilar s ta te of the steel in the surroundings of increased humidity and a large temperature range is typical for the behaviour of this kind of materials. Anather important problem is the changing terrain which leads to the leaning of the structure on the si de its apse wbich is placed at the side of Golden Hörn. The science and investigation metbods for both problems will result in the preservation of the monument. The following of the chronology of the pain~obs on the monument shows us the state of the church in an environment of higb hurnidity, aerosols, gasses and solid partides dissolving on the wet surface of the frame.

In 2008, Bulgarian experts examined the metal facings. They deterrnine the condition of the varnish dyer's film and the unprotected metal surface. An experiment (Kalchevska, K., R. Ganev, 2008) in the Institute of metal science, equipment and technology - BAS was made with a piece of steel tin from the outer metal facing which dates around 1895 (Bulgarian State Archive, (a)). The experiment showe.d that the facing was of low level quality, because of the amount and the intensity of the different types of destructions on it. These characteristics lead to destructions in the structure of the film under the influence of weather. The chernical elements in the structure are carbon 0,07; silicoo 0,01; phosphorus 0,02; maoganese 0,30; sulphur 0,03; chrome 0,03; oickel 0,10; cuprum 0,15%. They showed that the coostructional steel is low-classed and low-priced. The examined detail responded to steel w ith braod ST K 35 N!! 1,0208, I? IN 17115 for steel RSt 35-2.

The corrosion of the steel and the constaot influences of the atmospheric conditions lead to reduction of the adhesion of the coating. The corrosion on tlıe internal and the external casings is expanding inside the construction. The histarical condition and the general micro environmeot of the monument are the basis for the development of corrosion since 1920. Even though the church was constantly coated with film, its current state sbows that the needed measures were not taken in time in conditions ofhumidity and ever changing temperature regime.

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Fig. ı. St. Stefan chw-ch in Istanbul. General view before the restorarion.

Fig. 3. St. Stefan church in Istanbul. View before the restoration

Fig 2. St. Stefan churcb in Istanbul. Nortb facade before the restoration

Fig 4. Rusted floor joists in the church basement

2. Condition of the coating from 1895 until World W ar 2.

There are documentary evidences about the maintenance of the monument over the years. They explain the obvious negative results from the development of conosion. In the factory, just before delivery, the facings were coated with miniuro and linseed oil. During their transportation by water, they undergo several changes including a development of conosion. After their installation, the architect Hovsep Aznavur suggested the paint film to be removed mechanical way before painting the whole structure. He wanted to avoid the development of conosion, but his suggestion was not accepted by the constructioo committee. Instead, its members decided to scrub off only the parts where the conosion was evident.

Sioce the begioning of the coostruction, the steel elements remain,ed unprotected for two and a half years. The church, fitted with internal and extemal facings, was left unpainted for 1 O months. This resulted in an increase of corrosion. There is no clear information about the painting of the steel construction, but it is said that it should be treated with "a layer of protective paint" (CSA, (b)). The first exterior painting should have made on the pre-coated layer of miniuro with the german "Beghaus" paint, which contained metal oxide.

W e can fınd eviden ce for development of conosion in the state of the church in ı 9 ı 7. At that time the main water discharger pipes of the church were damaged during cleaning. The tin coating was damaged and was partially covered with rust (Fig.S). This means that it was of low quality and was not treated with high-quality materials. Those drawbacks occurred a decade after the building was

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finished. According to the requirements of the investor, tin sheets of size 3.30 x 0.90 m, with ribs of 1.5 cm; covered with a defensive layer, placed of gal vanic way, w ere provided for the roof of the na os. The sheets should be putona basis ofimpregnated pine with thickness of2.7 cm. They are double and are fixed with iron nails covered with tinned iron, whose heads must be covered with a small piece of lead. Galvanized steel sheets with dimensions of 2.80 x 0.95 x 1.5 cm were provided for the roof of the beli tower and the four terraces near it. Construction task provides a kind rooftop terrace, shaped areund the nave and transept to drain a system of rigoli (water dischargers). In order toprevent them from clogging, they should be coated with a "coated on ditches from drawn sheet metal" (CSA, (c)). The church should have 8 water dischargers with diameter of 13 cm and a 24 drip made of cast iron, serving water from the roof. Requirement for horizontal girders and detents is to be made of pooled galvanized steel, attached to the roofridge using the "steps" oftinned iron and solder.

The architects Alexi Nachev and Georgi Nenov, who gave opinions on the construction job, paid special attention to the installation of the cover of the roof and recommended that it should be deterrnined exactly how the roof covers must be attached to each other between the iron facade panels (CSA, (d)). The detailed descriptions from the repair works in 1917 lead to the conclusion. that the finishing works such as isolations, installation of water dischargers and drains were not done properly, which lead leakages between the elements, water retention in the ground areas which lead to rust formation. In 1923 and 1924 the old paint coatings were removed mechanically. The areas witlı a lot of corrosion were cleaned meclıanically and the way of thennal action. The project planned applications of three-layer protective coating (CSA, (e)). The repair works were not done properly because of economization on the materials and resources, and corruption activities (CSA, (f)). In 1928 the beli tower remained covered only with the factory protective coating.

The condition of the temple in the 1930s is critical. There are evidences from which we can conclude that the terrain changes started at that time. Also, as a result of improperly done repair works on the higher parts of the churcb and the badly installed gutters, conditions for water penetration from the roof to the construction were created. This led to accelerated corrosion processes not only on the facade facing, but also from the inner parts to the fundament as well (CSA, (g)). The biggest repairs were done in the period before World War 2 funded by a loan from Bulgaria. The materials and the technology for the repair works showed that the state of the temple was analyzed very carefully and responsibly at that time. The mechanical way of deaning covering of paint film American stamp "Murfi" were projectedat that time (CSA, (g)).

The Construction details of the church are not treated witb pa int coating after delivery to the ground in the middle of the 90s of the XIX century. The original certificate of quality steel shows that in 1894 in Vienıia, studies were performed in the quality of steel. Mod~rn interpretation of the document shows that the yield strength of the steel meets the brand St. 5, according to the table for resistance of materials. At the border of the demelition of the results corresponding manganese steel 40 G. The difference in the marks can be explained by the requiremeııt for the use of lıigb quality steel and the presence of natural alloying elements such as manganese, which is confınned by the test specimeos with X-ray analysis of the sheet froQl the external facade faciog the church (Ivanova, B., R. Ganev, 2009).

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Fig. 5. Rusted detail offinishing in emporia Fig 6. Detail from the south facade of the transept

The analogies from the state, the fate and the results from suck restaration interventions in such iconic buildings in Chile, France, Uhaine and Lithuania, which were assembled in from the 60s of XIX to the 30s of XX c. show that the Bulgarian church in Istanbul is one of the most vulnerable and poorly maintained buildings. One of the examples, wlıich shows a successful restaration with strong fınancial support is the restaration of the church "St. Barb" in France (Commamaille, L. 2009). Its restaration began in 1997. It costed 7,5 million francs and the church was saved fi:om conosion.

Some problems on church restaration are subject of an international team from Bulgaria, Czech Republic (lvanova, B., R. Ganev, M. Drdacky, .2013), and Canada. Preliminaıy results from investigations on improvement the durability of rusted coustruction elements using coatings on the basis of calcium sulfonates (Yao, P., S. Lee, 2011) were publisbed by N. Barovsk:i and W.Senick (Barovski, N., W. Senick, 2013).

3. lncreasing of steel structure service life

The increase the durability of rusted steel elemen ts on old structures is of great im portance w ith a view to keep them for a long time and reducing the operating expenses. When a stmcture is subjected to the action of con·osion agents fi·9m the environment both the rusting of steel ınembers and destı·uction usually take place. The result is that operating conditions are getting worse and, in many cases, the stı·uctures may be vigorously daınaged.

This problem has not been solved due to the great variety and cornplexity of factors influencing on the con·osion process. There are rnany structures exposed to the aggressive agents of sea enviwnrnent and many practical expeıience in protecting the steel conosion. The general idea is orientated to application of protection covers on steel suıfaces. It is very important that used products are rernain stable propeıties during the time.

The fact that a large number of existing structures are being deteriorated with time by steel conosion due to environrnental exposure, and conosion is one of the main causes for the limited durability. The idea to improve the durability of old steel structures is connected to the use of a new generatian anticonosion composite material. Such material is based on High Ratio Co-Polyrnerized Calcium Sulfonate rust mitigation system and tested for repairing of conoded steel bridges and structures. Higb Ratio Co-Polymerized Calcium Sulfonate coatings are produced by a complex series of proprietary reactions:

sulfonation; neutralization and over basing; carbonate modification.

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These reactions produce a very stable complex which is cheınically bound to the sulfonate backbone. The High Ratio Co-Polymerized Calcium Sulfonate cheınistry imparts the following performance properties:

hydrophobicity - resistant to the egress· of moisture; polarity - superb metal wetting and moisture displacement; inlıibition - buffering the PH at coating 1 metal interface ; physical barrier - a proprietary process grows uniform synthesized crystals which increase the

path length moisture will have to travel to get to the metal surface.

4. Technological aspects before surface coating

Smface preparation using lıiglz pressm·e ıvater cleaning (HP WC) ımits : The structure (or the portions of it to be coated) i ncluding flushing of the crevice corroded joints and connections are to be cleaned using a 345 bars (5,000 psi) bigh-pressure water deaning with a zero degree rotating tip at a maximum of a 1 O cm ( 4 ") stand off distance) to a cleaned s urfa ce to remove loose paint and loo.se rust hand or power tool deaning maybe used in iı:ı,accessible areas or when water deaning is not possible (Fig.7 & Fig. 8). In some cases after HP WC there are areas of tightly adhered oxide which was not removed. This tightly adbered black oxide even though is highly contaıninated with chloride and/or sulfates and/or ·rutrates and if allowed to remain, will result in delamination of the black oxide substrate and the coating which has adbered to it and must be removed.

\" : . \,~

Fig. 7. Surface high pressure water cleaniog Fig 8. High pressure water cleaning units

i Non Visible Contaminants: When it is expected (and/or confirmed by testing) that the surface of the steel is contarninated witb soluble salts (Chlorides and/or Sulfates &/or Nitrates). High pressure water deaning should be fınished with or incorporated in to the wash water initially a 100:1 solution of Termaciean TC7101 Soluable Salt Remover to remove those salts. Just washing with water is not adequate because the salts are chemically and polar attracted to steel.

D1ying: It is required that even if the joints and connections look dry - that they be blown dry with clean, dry, oil free, high pressure compressed air. Application Temperature, Dew Point, Relative Humidity: minimum + ıoc (5°F) application temperature, +2°C (5°F) temperature dew point spread, 99% relative humidity.

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5. Termarust technology for rust protection

Products in t/ıe system: Termarust Technologies manufactures a unique single coat coating system using an advanced technology material laıown as a High Ratio Co-Polymerized Calcium Sulfonate (HR CSA). This System should not be confused with Calcium Sulfonate Modified Alkyds. The system is a single-coat, three-step system designed and engineered exclusively for encapsulation ( overcoat) of existing aged paints, or re-coating of old and/or new prepared structural steel (Fig. 7.). The Termarust TR2200L V Penetrant/Sealer with the Tennarust TR2 100 Primer/Topcoat solves the

-·problem of crevice corrosion by chemically stopping it, rather than covering it up with film forming paints. Due to series TR2200LV HR CSA's low viscosity and chemistry, it has the ability not only to neutralize acidity, and form a flexible seal, it is also the ideal solution in applications with:

pack rusted j oints crevices; back to back angles; corrosion frozen beaıings; steel structures such as: bridges, towers, cracks, cable systems; steel structures that vibrate, expand and cootract due to temperature (climate); where a penetratiog, moisture scavenging acid neutralizing corrosion inhibitor is necessary.

High perfonnance TR2200LV HR CSA's is desigoed to stay active in joints, connections, bearings, pin connections and inaccessible areas which cannot be cleaoed properly (Fig. 8).

Fig.7. Termarust- one coat, tbree-step system Fig. 8. Application ofTermarust Penetrant

Field of Proven Peıformance: With proper deaning and application the Termarust coating system is covered by a 5-year warranty that includes crevice corroded joints and connections. On huodreds of structures the Termarust coatings are more than 5 years old, with no warranty claims. Based on accelerated testing the Termarust System has been shown to haveaminimum service life of25+ years. Overcoat versus Recoat: Although total removal of heavy rust scale and contamination is essential total removal of tightly adhered centaminant free rust and existing coating is not essential. The Termarust System has been developed as both an overcoat and recoat system for tightly adhered coatings and contaminate free rusi. '

6. Conclusions

1. Termamst is a One Coat, Three-Step System: After 34,5 MPa (5000 psi) High Pressure Water cl eaning and blowing connections dry with 6,9 MPa (1 00 psi) cl ean dry air apply wet-on-wet: application of Termarust TR2200L V Penetrant/ Sealer into joints and connections, application of Termarust TR2100 Self-Priming Topcoat as a stripe/caulk coat, and/or spot prime to all joints and exposed metal surfaces, followed by an additicnal application of the Termarust TR21 00 S elf Priming Topcoat all done "wet-on-wet"- no waiting between steps.

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2. Overcoating: removal of lead paint not required; no generatian of contaminated surface preparation media. No flushing of equipment that generates hazardous solvents.

3. Savbıgs in cost and time: Using the Terri:ıarust System a. total installed cost savings of more than 50% is commonly realized when compared to conventional three coat Zinc Epoxy U rethane systems.

4. Ot/ıer benejits: All colors are available - Termarust Teclınologies' colors are extremely fade and cbalk resİstant and have superior color retention; Environmentally Friendly - Termarust's coatings are easy and safe to work witlı, require no rnixing, catalyzing or thinning and they geoerate no hazardous waste. Life Cycle Cost Saviogs - In addition to providing a sigoificant cost savings for mainteoaoce painting the cost per applied year of service expected life cycle cost savings are even more significant.

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Agencia "Fokus": AreHUIDI "<l>oeyc", 2012: http://www.focus-news.net/?id=f21537 (April2013).

Barovski N., W. Senick, 2013: Barovski N., W. Senick, 2013. "Improvemeot of Durability of "St. Stefan" Iron church in Istanbul", Journal of Materials Science and Technology, Vol. 21, NQ ı, pp. 3-13.

BNT, 2012: http://bnt.bg/bg/news/view/91752/bez_liturgija_ v jeljaznata_cyrkva_sv _stefan (April 2013).

Commamaille, L. 2009: Commamaille, L. Eglise Sainte-Barbe de Crusnes http:/ /www. memotraosfront. un i -saarland. del e gl ise_ crusnes .sh tml.

CSA (a): Central State Archives, fund ı66, inveotory. ı, arehive unit 121, sheet 13; f. 246 K, inv. 1, a. u. 69, s. 102.

CSA (b): CSA, finv. us; finv. Us

CSA (c): CSA, f. 166 K, inv. ı, a. u. 120, s. 326. Constuction de l'eglise Bulgare a Phanar de la come d 'or. f:abier des cbarges. Clauses et conditions geoerales.

CSA(d): CSA, f. 246 K, inv. 4, a. u. 75, s. 4-6, (12.05.1917).

CSA(e): CSA, f. 246 K, inv. 3, a. u. 340, s. 62- 63 (fr. lang.).

CSA(f): CSA, f. 246 K, inv. 3, a. u. 340 (Constantinople, 9.06.1923; 27.06.-10.07.1924).

CSA(g): CSA, f. 246 K, inv. 3, a. u. 594,597.

Dnevnik, . 2012: http://www.dnevnik.bg/bulgaria1'20 12/03/0511780740 _istanbul_remontira jeliaznata _ curkva _sv _ stefa o_za_2/ (April 2013).

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Ivanova, B., R. Ganev, 2009: liBaHOBa, En ., P. raHeB, 2009. ,)l(emı30TO" 11 CTOMaHaTa B xpaMa ,CB. CTe<tıaH" B I1cTaH6yn", llcwemHuıfu, pecmaepaı{ufl, Jlty3eu, 2009, 6p. 1-2, c. ı9 - 26. (Ivanova, B., R. Gaoev. The "iron" and the steel in the temple St. Stefan in Istanbul. Mommıents, restoration, museums, vol. ı, pp. 19 - 29.

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Ivanova, B, R. Ganev, M. Drdacky, 2013: Ivanova, B, R. Ganev, M. Drdacky, "Historical and Condition Survey of the St. Stefan Bulgarian Metal Church in Istanbul", International Joumal of Architectural Heritage& Conservation, Analysts, an_d Restoration, Volume 7,_ Issue 6. pp. 693 - 714.

Kalchevska, K., R. Ganev, 2008: KanqeBCKa, K., P. raHeB, "HOBI1 M3CJJe,!.(BaHIDI Ha noi<pHTIDITa M CTOMaHaTa OT KOHCTpyı<UIDITa Ha 6'bıırapcKaTa qepKBa ,CB. CTe<jlaH" B HcTaH6yn", llaMemHıtıfu, pecmaepazJlm, My3eıt,. 2008, 6p. 1-2, c. 39- 44. (Kalchevska, K., R. Ganev, ''New investigations on conosion protection coats and the steel from the construction of the Bulgarian church St Stefan in

-. Istanbul, Monuments, restoration, museums, 2008, vol. 1 - 2, pp. 39-44).

Parvanova, M. 2011: M Il'bpBaHoBa, M. C eceMeCM crracm3aMe ,CB. CTe<}laH" B HcTaH6yn, 2011 http://www.rnonitor.bg/article?id=305474 (April2013).

Prikluchi nabiraneto, 2012: IIpHKJIIO'lli Ha6MpaHeTO Ha cpe.ı:ı:cTsa qpe3 srns 3a xpaMa "CB. CTe<jlaH" B UapMI'pa.ı:ı: (April2013).

Remontat na carkvata, 2012: PeMOHThT Ha JJ.'bpK.BaTa "CB. CTe<}laH" B HcTaH6yn me eTpysa 2 MJIH .ı:ı:onapa 02.07.2012 http://www.vesti.bg/index.phtrnl?tid=40&oid=4944251 (April2013);

Yao, P., S. Lee, 2011: Yao, Pradeep Kodumuri, and Seung-Kyoung Lee, 2011. "Performance Evaination of One-Coat Systems for New Steel Bridges", Report No.FHW A-HRT-11-046, June.

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