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Öğe A new approach to stone deformation: stone deformability index(Ice Publishing, 2012) Karaca, Zeki; Onargan, TurgayIn the present study the deformation behaviour of marbles (Nacre, Yatag. an White, Milas White) and limestones (Bursa Beige, Burdur Beige, Orient Pink) over short time periods was investigated under two loads, 19 MPa and 75% uniaxial compressive strength (sUCS) for 7 h. During the 19 MPa tests, all specimens demonstrated a regularly non-linear elasticity in secondary stage but this regularly non-linear elasticity was not observed during the 75% sUCS tests. The non-linear elasticity decreased as a function of time and ultimately ended. In the secondary stage, the ratio of the lowest strain value, epsilon(l), to final strain value, epsilon(f), was defined as the stone deformability index (SDi). Building stone type and strain value were observed to be two important factors in SDi, which was found to be lower for the limestones than the marbles. The SDi decreased with increasing stone strength. The crystalline size was also observed to be an important factor in the SDi of marbles.Öğe Assessment of the results of the pendulum friction tester (EN 14231) for natural building stones used as floor-coverings(Elsevier Sci Ltd, 2013) Karaca, Zeki; Gurcan, Sevgi; Gokce, Mehmedi Vehbi; Sivrikaya, OsmanThe main scope and parameter in choosing stone materials for floorings are unquestionably safety and slip resistance. The standard EN 14231 is one of those developed for natural stones. The device used for the tests of this standard, the pendulum coefficient friction tester, determines the slip resistance value of floorings in angle. Standards and their testers have constantly being developed. When this point of view is considered, EN 14231 has not yet been criticized. In this study, EN 14231 and the results obtained by the pendulum tester were for the first time analysed in terms of characteristics expected from a standard. For experimental studies, marble, limestone, travertine and granite samples currently in use as natural building materials were used. For each type of stone, four well-known and widely used stones that had surface roughness less than 1 mm were chosen. In this respect, 384 pendulum tests were conducted on 192 samples and more than 2200 angles were read from F scale. Depending on these readings, the dry slip resistance value-wet slip resistance value (DSRV-WSRV) relationships of marbles, limestone, travertine, and granites were investigated. Except travertine, DSRV-surface roughness and WSRV- surface roughness relationships of the samples were investigated. In addition, DSRV- cavity surface area and WSRV- cavity surface area relationships of travertine samples were investigated. After the evaluation of the test results, it was observed that, in general, higher correlations were obtained from wet samples compared to dry ones. The highest correlations were obtained from wet limestone samples. On the other hand, the lowest correlations were determined on the marble samples. Besides, petrographic characteristics and the physical characteristics of the stones such as, surface roughness and surface cavities were not recorded to have had any determinative effects on the results of the pendulum tester. According to the data obtained in this study, EN 14231 and the pendulum tester were seen to have fallen short in distinguishing both different types of natural stones and different groups of the same type of stone. For this reason, new researches should be made on EN 14231 and the pendulum tester device and both should be developed further. In the light of these results, EN 14231 was concluded to have been unsatisfying in terms of the characteristics expected from a standard and its applicability for slip resistance tests of stone materials to be used in floorings. (C) 2013 Elsevier Ltd. All rights reserved.Öğe Biofouling of marbles by oxygenic photosynthetic microorganisms(Springer Heidelberg, 2015) Karaca, Zeki; Ozturk, Ayten; Colak, EmelPhototrophic microorganisms disfigure the surfaces of different types of stone. Stone structure is damaged by the activity of photoautotrophic and other microorganisms. However, to date few, investigations have been undertaken into the relationship between microorganisms and the properties of different types of marble. In this study, biological activity of photoautotrophic microorganisms on three types of marble (Yatagan White, Giallo Anticato and Afyon White) was investigated under laboratory conditions over a short period of time. The three types of marble supported the growth of phototrophic microbial communities on their outer and inner layers, turning their original colour from white to a yellowish green colour. The porosity of the marble types facilitated filamentous microbial growth in the presence of water. Scanning electron microscope analysis revealed the accumulation of aggregates such as small spherical, fibrillar, calcified globular bodies on the inner surfaces of the marbles. This suggests that the microscopic characteristics of particular marble types may stimulate the growth of certain types of microorganisms.Öğe Classification of dimension stone wastes(Springer Heidelberg, 2012) Karaca, Zeki; Pekin, Abdulkerim; Deliormanli, Ahmet HamdiFor countries in which the stone industry is well developed, opposition to quarry and plant waste is gradually increasing. The primary step for waste control and environmental management is to define the problem of concern. In this study, natural building stone wastes were classified for the first time in the literature. Following on-site physical observations and research at more than 50 quarries and 20 plants, stone wastes were classified as (1) solid, (2) dust and (3) semi-slurry, slurry and cake. As a result of this study, the characteristics of wastes, their main environmental threats and the industries in which wastes could be used were defined for each group.Öğe Comparative review of CGS and EGS in energy and environmental scope(Amer Chemical Soc, 2013) Cetiner, Ziya S.; Uyusur, Burcu; Ozsu, Eren; Karaca, Zeki; Sanliyuksel, Deniz[Anstract Not Available]Öğe Determining the geochemical characteristics of geothermal resources and generating a geothermal information system of thermal waters in Biga Peninsula, NW Turkey(Amer Chemical Soc, 2013) Şanlıyüksel Yücel, Deniz; Yücel, Ali Mehmet; Karaca, Zeki; Çetiner, Ziya S.; Erenoğlu, Ramazan Cüneyt; Akçay, Özgün; Kamacı, Celal; Çalışkan, HidayetÖğe Grain properties, grain-boundary interactions and their effects on the characteristics of marbles used as building Stones(Elsevier Sci Ltd, 2015) Karaca, Zeki; Hacimustafaoglu, Ramazan; Gokce, Mehmedi VehbiIn this study, the effects of relationships of micro-structure, grain size and grain boundary of 15 well-known worldwide marbles on some physical and mechanical properties (dry unit weight, porosity, uniaxial compressive strength, tensile strength) and on abrasion loss value were investigated in detail, being the first in terms of elaborateness in the literature considering the mentioned features. 10 different samples were tested for each marble in each test. Microscope images were grouped as intergranular properties (shape of grains, shape of grain aggregates, grain boundary type and pressure solution), intra-granular properties (twinning and alteration) and deformation. All marbles which were tested were found to be of heteroblastic texture. Nine samples were monomineralic marble while six were polymineralic. It was determined that grain characteristics and grain boundary interaction affected dry unit weight, porosity, uniaxial compressive strength, tensile strength and abrasion loss value of each marble tested. (C) 2015 Elsevier Ltd. All rights reserved.Öğe İHA Destekli Dijital ve Termal Kamera Görüntülerine Dayalı Jeotermal Analiz Yöntemleri(2015) Akçay, Özgün; Erenoğlu, Ramazan Cüneyt; Yılmaztürk, Ferruh; Karaca, Zeki; Erenoğlu, OyaÖğe Relationship between Slipperiness and Other Characteristics of Stones used as Flooring Slabs(Asce-Amer Soc Civil Engineers, 2016) Bellopede, Rossana; Marini, Paola; Karaca, Zeki; Gokce, Mehmedi VehbiSlip resistance is an essential parameter when dimension stones are used as inner and outer floorings. Declaration of performances of stones and their surface finishes (sawn, honed, polished, hammered, flamed, sandblasted, or brushed) in relation to conditions (wet or dry) in Conformite Europeenne (CE) marking is essential for pedestrian safety. In this study, 130 samples taken from 81 stone types belonging to 13 types of petrographic families were tested according to the EN 14231 Standard, taking different finishes into consideration, during a ten-year period in the Marble Laboratory of Politecnico di Torino (Italy). A high number of pendulum friction tests (1,560) were conducted on 780 samples, and more than 7,000 readings were taken. On the basis of the obtained results, significant relations were found between the tested petrographic families and the types of finishes. A high correlation between open porosity, quartz content, and slipperiness of the stones with honed surface finishes was found. Moreover, the importance of the petrographic characterization of the stone, in relation to the declared surface finish, emerged as each petrographic family responded differently (according to its composition) to the action of the finishing abrasive.Öğe Relationship between the mechanical properties and the surface roughness of marble(Carl Hanser Verlag, 2012) Karaca, ZekiBecause dimension stone is a natural building material, polishing is important, especially when deciding how the stone will be used. However, the effects of stone polishing are not fully understood. In the stone industry, determining the best polishing process is often performed by trial and error or is based on an expert's experiences. This paper reports the result of a study conducted using selected true marble specimens to determine their surface roughness values and to relate these values to their grain sizes, uniaxial compressive strengths, tensile strengths, and Bohme abrasion values. For this purpose, five different true marble specimens were selected. The significance and validity of the relationships between the mechanical properties and the final surface roughness values were interpreted using test statistics. It was found that there were statistically significant correlations between uniaxial compressive strength and tensile strength and the surface roughness of the studied marble specimens. It is not clearly known whether the Mime abrasion loss value has any relationship with the surface roughness of the polished marble or not. It is thought that the present findings could help practitioners and consumers as well as architects and engineers to make more informed choices about the type of marble to use for specific applications.Öğe The Activity of Oxygenic Photosynthetic Microbial Consortia on Different Granites(Foundation Environmental Protection & Research-Fepr, 2014) Ozturk, Ayten; Karaca, Zeki; Unsal, TubaDeterioration of stone is a combined process caused by physical, chemical and biological factors especially, microbial growth. Various microorganisms are playing a key role in the weathering of historical artifacts, buildings, and monuments made of granite, marble, and other dimension stones. In this study, the biodeterioration of three types granite, Blue Pearl from Norway, Pergamon Grey from Turkey, and Rosa Porrino from Spain were studied for thirty days under laboratory conditions. The results showed that two of the granite surfaces, Pergamon Grey and Rosa Porrino, supported a heavy colonization of phototrophic microbial consortia. These results also showed that filamentous phototrophic microorganisms were dominant on the surfaces of the granites and indicated that the porosity, the availability of water and chemical composition of the granite have encouraged colonization and caused modification on the surfaces. The filamentous aggregates, possibly calcified fibrillar bodies in the inner parts of granites were also detected by SEM studies.Öğe The Activity of Oxygenic Photosynthetic MicrobialConsortia on Different Granites(2014) Öztürk, Ayten; Karaca, Zeki; Unsal, TubaTaşın aşınması fiziksel, kimyasal ve biyolojik, özellikle mikrobiyal gelişmenin neden olduğu kombine birişlemdir. Çeşitli mikroorganizmalar granit, mermer ve diğer taşlardan yapılmış heykel ve binaların; tarihieserlerin aşınmasında anahtar rol oynamaktadır. Bu çalışmada, Blue Pearl (Norveç), Bergama Gri (Türkiye)ve Rosa Porrino (İspanya) olmak üzere üç farklı granitin laboratuar koşulları altında 30 gün süreyle biyolojikaşınması araştırılmıştır. Sonuçlar, Bergama Gri ve Rosa Porrino granitlerinin yoğun bir fototrofikmikroorganizma kolonizasyonunu desteklediğini göstermiştir. Granit yüzeyinde ipliksi fototrofikmikroorganizmalar daha baskındır. Porozite, suyun kullanılabilirliği ve granitin kimyasal bileşimikolonizasyonu etkilediği ve bunların yüzeyde değişmelere neden olduğu görülmüştür. SEM çalışmalarındagranitin iç kısımlarında kalsifiye yapılar olarak ipliksi yığınlar tespit edilmiştir. SEM araştırmaları, üçgranitde de ipliksi mikroorganizmaların ipliksi uzantılarıyla taşa yapıştığını ve bunların granit içine nüfuzettiğini göstermiştirÖğe The Relationship Between Mineral Content and Flocculant Characteristics for Slurry Waste Water Recycling at Marble Processing Plants(Springer Heidelberg, 2016) Bayel, Diler Katircioglu; Karaca, Zeki; Onen, Vildan; Deliormanli, Ahmet HamdiThe requirements for clean water in marble processing are partially realized by treating and recycling slurry wastes from the cutting and processing plant. In this study, the flocculation of calcitic and dolomitic (21.2 % MgO) marble wastes was investigated using six flocculants with different molecular weights and anionic levels. Nine solutions between 0.1 and 2.5 mg/L were prepared, and marble waste samples were treated in natural, slightly acidic, and alkaline media. The anionic flocculants had a more dramatic effect on the slower-settling dolomitic marble than the calcitic marble. Calcite precipitation was better in an alkaline medium, while dolomitic marble precipitation was better at a slightly acidic pH of 6.
