Conservation and Restoration of Cultural Heritage / Kültür Varlıklarını Koruma ve Onarım
Permanent URI for this collectionhttps://hdl.handle.net/11147/23
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Article Citation - WoS: 171Characteristics of Brick Used as Aggregate in Historic Brick-Lime Mortars and Plasters(Elsevier Ltd., 2006) Böke, Hasan; Akkurt, Sedat; İpekoğlu, Başak; Uğurlu, ElifMortars and plasters composed of a mixture of brick powder and lime have been used since ancient times due to their hydraulic properties. In this study, raw material compositions, basic physical, mineralogical, microstructural and hydraulic properties of some historic Ottoman Bath brick-lime mortars and plasters were determined by XRD, SEM-EDS, AFM, TGA and chemical analyses. The mineralogical and chemical compositions, microstructures, morphologies and pozzolanicities of the brick powders and fragments used as aggregates in the mortars and plasters were examined to find out the relationship between hydraulic properties of the mortars and the bricks. The characteristics of bricks used in the bath domes were also determined to investigate whether the brick aggregates used in mortar and plasters were prepared from these bricks. The results indicated that the mortars and plasters were hydraulic owing to the presence of crushed brick powders that have good pozzolanicity. The brick powders bad high pozzolanicity because they contained high amounts of calcium-poor clay minerals in their raw materials that were fired at low temperatures. On the other hand, bricks used in the domes had poor pozzolanicity with different mineralogical and chemical compositions from bricks used in mortars and plasters. Based on the results of the analysis, it was thought that the bricks manufactured with high amounts of clays were consciously chosen in the preparation of hydraulic mortars and plasters. (C) 2006 Elsevier Ltd. All rights reserved.Article Citation - WoS: 41Citation - Scopus: 42Characterization of Materials Used in the Execution of Historic Oil Paintings by Xrd, Sem-Eds, Tga and Libs Analysis(Elsevier Ltd., 2009) Şerifaki, Kerem; Böke, Hasan; Yalçın, Şerife; İpekoğlu, BaşakIn this study, material characteristics of historic oil paintings in a 19th century church in Ayvali{dotless}k/Turkey were investigated to propose the treatments to be used in their conservation and protection. For this purpose, physical, chemical and mineralogical compositions and the microstructure of the paintings were determined by X-ray Diffraction, Scanning Electron Microscope, Thermo Gravimetric Analyzer, Differential Scanning Calorimeter, Infrared Spectroscopy and Laser Induced Breakdown Spectroscopy. Analysis results showed that the paintings were composed of very thin binding and white priming layers on which the pigments were applied. Binding layers were composed of polymerized vegetable oil with Zinc Oxide. Priming layers were composed of anglesite mineral in polymerized vegetable oil. Pigments used in paintings were mainly green earth, red chrome and iron oxide.Article Citation - WoS: 50Citation - Scopus: 51The Use of Brick-Lime Plasters and Their Relevance To Climatic Conditions of Historic Bath Buildings(Elsevier Ltd., 2009) Uğurlu Sağın, Elif; Böke, HasanBrick-lime mortars and plasters have been widely used as water-proof materials in aqueducts, bridges and cisterns since early Hellenistic time. In this study, the characteristics of brick-lime plasters used in some Ottoman bath buildings were investigated in order to understand their relevance as plasters in hot and humid environmental conditions of the baths. For this purpose, basic physical properties, raw material compositions, mineralogical, microstructural and hydraulic properties of brick-lime plasters of some historic bath buildings in İzmir (Turkey) were determined by XRD, SEM-EDX, AFM and chemical analyses. The results indicated that their survival without loosing their strength and adhesion in hot and humid conditions of the baths was explained by their hydraulic characters due to the consciously use of porous and pozzolanic crushed bricks as aggregate in the manufacturing of plasters.Article Citation - WoS: 62Citation - Scopus: 60Properties of Roman Bricks and Mortars Used in Serapis Temple in the City of Pergamon(Elsevier Ltd., 2009) Böke, Hasan; Özkaya, Özlem AslanSerapis temple, which was constructed in the Roman period in the city of Pergamon (Bergama/Turkey), is one of the most important monuments of the world heritage. In this study, the characteristics of bricks and mortars used in the temple have been determined in order to define the necessary characteristics of the intervention materials, which will be used in the conservation works of the temple. Several analyses were carried out to determine their basic physical properties, raw material compositions, mineralogical and microstructural properties using X-ray diffraction, Scanning Electron Microscope and a Thermo Gravimetric Analyzer. Analysis results indicated that the mortars are stiff, compact and hydraulic due to the use of natural pozzolanic aggregates. The Roman bricks are of low density, high porosity and were produced from raw materials containing calcium poor clays fired at low temperatures.Article Citation - WoS: 49Citation - Scopus: 57Characteristics of Lime Produced From Limestone Containing Diatoms(Elsevier Ltd., 2008) Böke, Hasan; Çizer, Özlem; İpekoğlu, Başak; Uğurlu Sağın, Elif; Şerifaki, Kerem; Toprak, GülcanIn this study lime binder used in stone and brick masonry mortars of some historic Ottoman baths was examined to understand whether the binders were hydraulic or not. For this purpose the mineralogical and elemental compositions and the microstructure of lime binder were determined by XRD, SEM-EDS and TGA analyses. The results indicate that the lime used in the brick dome mortars of Ottoman baths was hydraulic. Taking into account the kiln and fuel conditions of the 15th century, the possibility of obtaining hydraulic lime at relatively low temperature was examined. For this purpose limestone containing diatoms was heated at a relatively low temperature (850 °C), then slaked and carbonated. After heating and slaking, calcium silicate giving hydraulicity to the lime was indicated by XRD and SEM-EDS analyses. These results show that the production of hydraulic lime at a relatively low calcination temperature (850 °C) was possible with 15th century kilns.Article Citation - WoS: 44Citation - Scopus: 54Protection of Marble Surfaces by Using Biodegradable Polymers as Coating Agent(Elsevier, 2009) Ocak, Yılmaz; Sofuoğlu, Aysun; Tıhmınlıoğlu, Funda; Böke, HasanBiodegradable polymers have been replaced over the synthetic polymers in many applications due to their good properties such as reversibility and biodegradability. Therefore they allow new treatment on the surface of the material to be protected and they fulfil the principles generally accepted by the International Conservation Community of Historic Monuments and Buildings. In this study, the efficiency of four different biodegradable polymers as protective coatings on marble-SO2 reaction was investigated. The polymers used were zein, chitosan, polyhydroxybutyrate (PHB), and poly-l-lactide (PLA). The mineralogical composition, bulk density and porosity of uncoated marble were determined. The water vapor permeability, water absorption by capillary forces, surface wettability, and color alteration of uncoated and coated marbles were measured. For sulphation reaction, marble slabs were coated with these polymers and then they were exposed at nearly 8 ppm SO2 concentration at 100% relative humidity conditions together with uncoated ones in a reaction chamber for several days for testing their protection efficiency. The extent of reaction was determined by leaching of gypsum formed on the marble surfaces in deionized water and then determining the sulphate content by ion chromatography. The protection efficiency of polymer treatments was expressed as comparing the gypsum crust thickness of the coated and uncoated marble plates. The comparison among the polymers showed that the surface hydrophobicity, water capillary absorption and structure of polymer would be important factors affecting the protection efficiency. The use of high molecular weight PLA (HMWPLA) polymer on marble surfaces provided significant protection up to 60% which was indicated that HMWPLA polymer seems to be promising polymer as protective coating agent in reducing gypsum formation on marble surfaces in the polluted environment.Article Citation - WoS: 31Citation - Scopus: 37Assessment of Material Use in Relation To Climate in Historical Buildings(Elsevier Ltd., 2007) İpekoğlu, Başak; Böke, Hasan; Çizer, ÖzlemClimate is among the most significant factors on the environmental performance, life span and/or durability of construction materials in buildings. Although some historical buildings have been abandoned and neglected for a very long period, their existence through centuries can be explained because of their durability to climatic conditions of the area where they are situated. In this study, construction techniques and characteristics of building materials used in some madrasas (historical education buildings) in Western Anatolia (Turkey) were examined in order to evaluate the conditions of the buildings by taking into account climatic conditions of the region. The studied Western Anatolian madrasas, which are in the moderate climatic conditions, were constructed out of rubble stone, brick and mortar in random bond with local workmanship by local builders who continued the older traditions and have survived for more than 300 years without maintenance and repair. On the other hand, most of the madrasa buildings in Central and Eastern Anatolia, which are in the steppe climatic conditions, were differently constructed with cut stone on their exterior surfaces to prevent the main structures of the walls composed of rubble stone and mortar from harsh climatic conditions of these regions. This study indicated that construction techniques and building materials appropriate to the climate might have been intentionally chosen for the survival of historical buildings over the centuries.Article Citation - WoS: 121Citation - Scopus: 136Quantification of Caco3-Caso3·0.5h 2o-Caso4·2h2o Mixtures by Ftir Analysis and Its Ann Model(Elsevier Ltd., 2004) Böke, Hasan; Akkurt, Sedat; Özdemir, Serhan; Göktürk, E. Hale; Caner Saltık, Emine N.A new quantitative analysis method for mixtures of calcium carbonate (CaCO3), calcium sulphite hemihydrate (CaSO 3·1/2H2O) and gypsum (CaSO 4·2H2O) by FTIR spectroscopy is developed. The method involves the FTIR analysis of powder mixtures of several compositions on KBr disc specimens. Intensities of the resulting absorbance peaks for CaCO 3, CaSO3·1/2H2O and CaSO 4·2H2O at 1453, 980, 1146 cm-1 were used as input data for an artificial neural network (ANN) model, the output being the weight percent compositions of the mixtures. The training and testing data were randomly separated from the complete original data set. Testing of the model was done with successfully low-average error levels. The utility of the model is in the potential ability to use FTIR spectrum to predict the proportions of the three substances in unknown mixtures.Conference Object Citation - WoS: 7Citation - Scopus: 7Investigation of the Pozzolanic Properties of Bricks Used in Horasan Mortars and Plasters in Historic Buildings(Trans Tech Publications, 2004) Böke, Hasan; Akkurt, Sedat; İpekoğlu, BaşakCrushed brick used in historic brick-lime mortars and plasters (Horasan) were characterized for understanding their properties to develop intervention mortars for conservation. Brick powders were separated from original mortars and plasters, and analyzed by XRD, SEM-EDS, TGA and pozzolanic activity (PA) measurements. The results showed that the microstructures of brick powders were not completely vitrified, and their XRD analysis failed to show the peaks for high temperature (T>900°C) phases. PA measurements of all brick powders showed an ample amount of artificial pozzolan property. Consequently, brick powders aimed for conservation of historic mortars must have high clay contents in addition to being low-fired (T<900°C) in order to produce maximum conversion into amorphous phase for ideal PA values.Article Citation - WoS: 8Citation - Scopus: 8Reducing Marble-So2 Reaction Rate by the Application of Certain Surfactants(Springer Verlag, 2003) Böke, Hasan; Gauri, K. LalSulfur dioxide (SO2), prevalent in the modern urban environment of industrial countries, attacks calcite (CaCO3) in marble. As a result, a gypsum (CaSO4.2H2O) crust is produced at rain-sheltered surfaces while areas exposed to rain experience accelerated erosion. We have investigated the effect of certain surfactants as protective agents against SO2 attack. We report that the anions oxalate (C2O4-2) and oleate (C17H33COO-) from solutions of their highly soluble alkali salt species are able to replace carbonate (CO3-2) in calcite producing less reactive substrate of oxalate and oleate of calcium. Experiments to measure the protection obtained by these treatments were carried out in the laboratory and field conditions at nearly 1 ppm and 10 ppb SO2 concentrations, respectively. We found that these treatments provided significant protection to marble exposed in sheltered areas, up to 30% reduction of reaction rate by treatment with 2 × 10-4 M sodium oleate and up to 14% by a 2 × 10-3 M with potassium oxalate solutions, but become ineffective over long term exposure when applied to surfaces exposed to rain. Carrara marble was used in the reported study. Ion chromatography was the analytical tool, which allowed precise measurements of ionic concentrations of these salts, the amount of their uptake by marble, and the thickness of the gypsum crust. X-ray diffraction allowed determination of the new minerals formed at the marble surface by the treatment with surfactants.