Yazar "Gokce, Mehmedi Vehbi" seçeneğine göre listele

Listeleniyor 1 - 8 / 8
  • Küçük Resim Yok
    Öğe
    Ancient Isaura Quarries in and Around Zengibar Castle (Bozkir, Konya), Central Anatolia, Turkey
    (Springer Heidelberg, 2020) Gokce, Mehmedi Vehbi; Ince, Ismail; Okuyucu, Cengiz; Doganay, Osman; Fener, Mustafa
    Zengibar Castle was built by the Isaurian during antique ages on the summit of Mount Asar, approximately 20 km west of the town of Bozkir, Konya, Turkey. The aims of this study are to determine the lithological, petrographic, and mechanical characteristics of the building stones that were used to construct the walls and buildings in Zengibar Castle in order to determine the quarrying techniques of these stones and to determine which structures they were used in. A number of antique quarries of various sizes were located in Isaura, four of which produced a significantly higher volume of building stones. These antique quarries were mostly located on hillsides in carbonate rock of the Late Triassic Dutdere formation located in the Bolkardagi Units and were run phase by phase. The porosity range of the rocks was found to be between 0.85 and 0.90% and the dry density and uniaxial compressive strength were found to range from 2.67 to 2.68 g/cm(3)and 83.10 to 96.60 MPa, respectively. The results of this study suggest that the stones that were quarried in these quarries were used as the main building material or flooring material in various constructions in Zengibar Castle, including religious buildings such as temples and chapels, social buildings such as dwellings, theaters, baths, fountains, and cemeteries, defense and security structures such as watchtowers, fortification walls, and city gates, in monumental tombs, and in stones in which reliefs and inscriptions were carved.
  • Küçük Resim Yok
    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, Osman
    The 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.
  • Küçük Resim Yok
    Öğe
    DETERIORATION AND CONSERVATION PROBLEMS OF HISTORICAL FOUNTAINS IN CAPPADOCIA-NIGDE
    (Parlar Scientific Publications (P S P), 2020) Akcaozoglu, Semiha; Yavascan, Emel Efe; Gokce, Mehmedi Vehbi
    Historical artefacts, monuments and buildings are an integral part of the socio-cultural, architectural and aesthetic features of the past civilizations. Cultural heritage, which is accepted as the common property of humanity, reflects the feelings and thoughts of civilizations that have lived from past to present. Fountains that are an integral part of the historical and cultural environment of a city are one of the most outstanding structures, as they are built to reflect the architectural and socio-cultural characteristics of the city. They are considered to be a bridge between the past and the future, and thus it is extremely important to ensure their sustainability as well as their preservation. The aim of this study was to document the historical fountains found in the city center of Nigde within the Cappadocia Region, create a report on these structures and draw attention to the issues regarding their preservation. For this purpose, a total of 13 fountains which are located in the center of Nigde were examined. The material and construction techniques and typologies of these fountains were determined and finally their physical conditions and reasons for their deterioration were investigated. In general, among the reasons for the deterioration of the fountains were found to be longterm natural and human effects. Preserving these fountains which are in danger of destruction and loss of function is a must in order to transfer such historical and cultural assets to the future. From this point of view, it is considered that this study will contribute greatly to future preservation and restoration works on these historical fountains which once served for a substantial social need of urban life.
  • Küçük Resim Yok
    Öğe
    Deterioration and conservation problems of historical fountains in Cappadocia-Nigde
    (Parlar Scientific Publications, 2020) Akcaozoglu, Semiha; Yavascan, Emel Efe; Gokce, Mehmedi Vehbi
    Historical artefacts, monuments and buildings are an integral part of the socio-cultural, architectural and aesthetic features of the past civilizations. Cultural heritage, which is accepted as the common property of humanity, reflects the feelings and thoughts of civilizations that have lived from past to present. Fountains that are an integral part of the historical and cultural environment of a city are one of the most outstanding structures, as they are built to reflect the architectural and socio-cultural characteristics of the city. They are considered to be a bridge between the past and the future, and thus it is extremely important to ensure their sustainability as well as their preservation. The aim of this study was to document the historical fountains found in the city center of Nigde within the Cappadocia Region, create a report on these structures and draw attention to the issues regarding their preservation. For this purpose, a total of 13 fountains which are located in the center of Nigde were examined. The material and construction techniques and typologies of these fountains were determined and finally their physical conditions and reasons for their deterioration were investigated. In general, among the reasons for the deterioration of the fountains were found to be long-term natural and human effects. Preserving these fountains which are in danger of destruction and loss of function is a must in order to transfer such historical and cultural assets to the future. From this point of view, it is considered that this study will contribute greatly to future preservation and restoration works on these historical fountains which once served for a substantial social need of urban life. © 2020 Parlar Scientific Publications. All rights reserved.
  • Küçük Resim Yok
    Öğe
    Effects of surface-finishing forms and cement-filling on porous dimension limestone deterioration in cold regions
    (ELSEVIER SCIENCE BV, 2011) Karaca, Zeki; Oztank, Nimet; Gokce, Mehmedi Vehbi; Elci, Hakan
    This work studies the influences of both surface-finishing forms and cement-filling on the durability of dimension limestone in cold regions. Freeze-thaw cycles, aqueous saline solution and their interactions with surface-finishing forms and cement-filling on stones were investigated for two types of porous limestone, Caribbean and Pewter Blend. Both deionised water and saline water composed of 20% NaCl by weight were used, and 28 freeze-thaw cycles were applied to the samples. The change in dry weight, porosity, and Bohme abrasion loss value was obtained for all test samples. It was observed that two types of porous limestone with cement-filling and different types of surface-finishing were influenced to different extents by freeze-thaw and salt. Experiments showed that stones to be used outdoors in cold regions should have relatively low initial porosity and that they should be fine-finished and cement-filled; these modifications to the stones will maximise the benefit received from the stones. (C) 2011 Elsevier B.V. All rights reserved.
  • Küçük Resim Yok
    Öğe
    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 Vehbi
    In 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.
  • Küçük Resim Yok
    Öğe
    The effects of bedding directions on abrasion resistance in travertine rocks
    (SCIENTIFIC TECHNICAL RESEARCH COUNCIL TURKEY-TUBITAK, 2015) Gokce, Mehmedi Vehbi
    Travertine rocks are currently used in various architectural applications, cut perpendicular or parallel to bedding planes. Travertine stones used without enough attention paid to the cutting directions easily wear off in locations where pedestrian traffic is heavy and can cause some unexpected complications in practice. This study was conducted to elucidate the effects of cutting directions on the abrasion resistance of travertine stones. Travertine blocks were cut perpendicular and parallel to bedding planes, and their abrasion resistances were determined by means of the Bohme abrasion loss test. Travertine blocks were chosen from 6 different quarries whose products are currently in commercial use in Turkey and abroad. The rocks used in this study were macroscopically and microscopically described in terms of sizes, distribution patterns, and area ratios of pores, which were calculated using image analysis technique; the effects of these features on the abrasion resistances of the samples were expressed numerically. The relationships between pore area ratios and the Bohme abrasion loss values, in relation to the bedding directions, were also studied. The issues of cutting travertine rocks perpendicular or parallel to their bedding planes and how to extend the lifespan are also discussed. According to the findings, surface abrasion losses in all travertine samples cut perpendicular to their bedding plates were found to have been less than those of the samples cut parallel. Moreover, sizes and distribution patterns of the pores were found to be effective on the abrasion resistance; the pores on the surfaces cut perpendicular were smaller in size, flatter, and discontinuous, while the pores on the surfaces cut parallel were relatively greater in size, connected to each other, and with larger surface areas.
  • Küçük Resim Yok
    Öğe
    The effects of freeze-thaw (F-T) cycles on the Godene travertine used in historical structures in Konya (Turkey)
    (ELSEVIER SCIENCE BV, 2016) Gokce, Mehmedi Vehbi; Ince, Ismail; Fener, Mustafa; Taskiran, Taha; Kayabali, Kamil
    Travertine, a building material used around the globe for its decorative and easy-to-be-worked features from past to present, is naturally exposed to the freeze-thaw (F-T) process in cold regions in winters. As a result of this process, building stones deteriorate partially or completely. The greatest factor during the F-T process is the existence of water. The water contained in the body (in discontinuities and pores) of a building stone freezes along with the fall of temperature below 0 degrees C. Following freezing, the volume of water contained in discontinuities and pores increases. New fractures develop on the surfaces of pores as a result of outward pressure due to this increase in volume. As the temperature drops below 0 degrees C, the volume of water increases again, due to freezing. This process repeats itself with the decrease and increase in temperature and causes undesired deteriorations in the bodies of stones. This issue is quite important from the point of view of preservation and restoration of historical buildings, and foreseeing the effects of the F-T process on new buildings to be designed. In this study, the effects of the F-T process on Godene travertine were investigated. Godene travertine is a stone that has been widely used in historical buildings in Konya, a city that also covers catal Hoytik, which is known as one of the oldest human settlements in Anatolia. The stone is still being used in buildings constructed in the region. Fresh travertine stones obtained from the quarry were exposed to freeze and thaw cycles in different numbers. Values of porosity (n), uniaxial compressive strength (sigma(u)), point load strength (I-s(50)), Brazilian tensile strength (sigma(t)), Bohme abrasion loss (BA) and P wave velocity (V-p) were statistically evaluated and thus, the effects of the number of cycles on basic physical and mechanical characteristics of the Godene stone were investigated. Furthermore, deteriorations that took place in historical structures in the region were case-studied. (C) 2016 Elsevier B.V. All rights reserved.