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: 27Citation - Scopus: 28Lime Mortar Technology in Ancient Eastern Roman Provinces(Elsevier, 2021) Uğurlu Sağın, Elif; Duran, Hasan Engin; Böke, HasanNatural pozzolanic aggregates were discovered during the Roman era and have been widely used in hydraulic mortar production. Despite the claims of ancient treatises, the properties of pozzolans and the technology of hydraulic lime mortars were well known and applied in the eastern provinces of the Roman Empire. In this study, the characteristics of lime mortar at the ancient sites of Aigai and Nysa located in Western Anatolia were investigated to elicit the technology applied. The raw material compositions of the mortars, the hydraulic properties of the binders, and the mineralogical and chemical compositions of the natural pozzolans used were determined via X-ray diffraction, X-ray fluorescence spectroscopy, scanning electron microscopy coupled with energy dispersive spectroscopy, and thermogravimetric analysis. The major and trace element compositions of the natural pozzolans were evaluated via multivariate statistical analysis to determine whether the same local raw material resources were used in their manufacture. The analytical results indicated that the Roman mortars were hydraulic, stiff, and durable materials due to the use of natural pozzolanic aggregates mostly comprising dacite. Although the aggregates had similar mineralogical compositions, multivariate statistical analysis revealed that their chemical compositions were clearly distinguishable, indicating the use of different sources of raw materials. Thus, it was inferred that similar pozzolan resources were known and deliberately used to produce hydraulic mortars in the eastern ancient Roman provinces.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.