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Evaluating the Rate of Stone Art Deterioration in Wadi Maghara and Wadi Mukattab, Sinai, Egypt  [PDF]
Sayed HEMEDA,Walid ALGHAREB
International Journal of Conservation Science , 2012,
Abstract: One of the key reasons for the status of Wadi Maghara and Wadi Mukattab as World Heritage Sites is the abundance of stone art present there. Unfortunately, in time, much of the stone art heritage in the two archaeological sites was lost, due to natural stone weathering processes, to static and dynamic actions and lately, due to the lack of preservation measures and to the action of people. That fragile art heritage is non-renewable and, therefore, it requires specialized management. Several stone facades in Wadi Maghara have embossed inscriptions of early rulers of Egypt, that document their expeditions to mine precious minerals, primarily turquoise and copper, that were found in the area. Wadi Mukattab (south of Wadi Maghara) is the valley of inscriptions. Over a distance of 3 km along this valley inscriptions can be found on the mountain rocks that have mostly been made by Nabateans (2nd and 3rd Century) but also by others, such as pilgrims, soldiers, merchants, throughout the centuries. In our case study, inscriptions from specific study areas were analyzed by using SEM, polarizing microscope, XRD, SEM with EDX, DTA-TGA, Grain Size Distribution, Pore Media Characterization and some stone samples were tested in the stone mechanics laboratory, to determine the physical and mechanical characteristics of the stone with carved inscriptions. Digital photographs were taken, with Geographic Information Systems software. Older images were compared with more recent ones and in order to classify and quantify the amount of deterioration that occurred over time. Various methodologies were applied to classify the images, and it was found that manual digitizing provided the best means for quantifying the amount of deterioration. Results showed that the damage was primarily caused due to the instability of stone structures, because of the extensive jointing and rock fall gravity, due to dynamic actions and the granular disaggregation of the stone surface. The methodology used in this study can be utilized to evaluate the rate of decay of stone art and therefore a useful tool for determining priorities with regard to the conservation of the Wadi Maghara and Wadi Mukattab sites. In addition, the rate of deterioration is useful in evaluating and quantifying the contribution of stone weathering to landscape evolution.
Macroscopical morphology of deterioration of the stone in the Cathedral of Seville, Spain
Alcalde, M.,Martín, A.
Materiales de Construccion , 1990,
Abstract: The lithotype mainly used in the construction of the Cathedral of Seville is the calcarenite from Puerto de Santa f/laria followed by the limestone from Espera. The primordial extrinsecal factor of deterioration is the atmospherical contamination, mainly sulphur oxides and smoke, within a humid environment. From both factors, the porose stone of a carbonated nature and the acid environment, we can deduce that the principal mechanism of deterioration is the chemical attack; the most important indicators of deterioration that have been found are the deposits and arenizations. In a "grosso modo" valoration we can say that the stone of structural employment is well conserved in its majority while the ornamental stone is degraded at 80%. Half the cresting is in a state of ruin and 20% of the tips have been removed or will have to be in the near future. El litotipo mayoritariamente empleado en la construcción de la Catedral de Sevilla es la calcarenita del Puerto de Santa María seguida de la caliza de Espera. El factor extrínseco de alteración primordial es la contaminación atmosférica, principalmente óxidos de azufre y humos, en ambiente húmedo. De ambos factores, piedra porosa de naturaleza carbonatada y medio ambiente ácido, puede deducirse que el principal mecanismo de alteración es el ataque químico y se ha encontrado que los indicadores de alteración más importantes son los depósitos y las arenizaciones. En una valoración a grosso modo puede decirse que la piedra de uso estructural se encuentra bien conservada en su mayor parte, y la ornamental degradada en un 80%. La mitad de las cresterías se encuentran en estado de ruina y un 20% de los remates han sido retirados o habrán de serlo próximamente.
Effectiveness of stone treatments in enhancing the durability of bioclastic calcarenite in (Granada, Spain)
Luque, A.,Cultrone, G.,Sebastián, E.,Cazalla, O.
Materiales de Construccion , 2008,
Abstract: Santa Pudia limestone, a biocalcarenite highly sensitive to decay, is one of the most commonly used building materials in historical monuments in the city of Granada, Spain. The compatibility between a variety of stone treatments (consolidants and/or water repellents) and this calcarenite was analyzed and the resulting improvement in durability assessed. To this end, a two-stage accelerated ageing process was implemented. In the first, freshly quarried, undamaged specimens were altered to resemble the weathered stone in buildings. The second was conducted after applying the various treatments to the artificially aged stone to test their effectiveness. While all the treatments studied (Tegosivin HL100, Silo 111, Estel 1100 and Tegovakon V) enhanced stone resistance to decay while barely affecting chromatic parameters, the most effective was Tegowakon V, as it provided the best results in the hydric tests on the limestone. La calcarenita de Santa Pudia es uno de los materiales rocosos de construcción más empleados en las edificaciones monumentales de la ciudad de Granada (Espa a). Se ha evaluado la compatibilidad de diversos productos de tratamiento (de consolidación y/o hidrofugación) con esta calcarenita y como son capaces de mejorar su durabilidad. Para ello, se han realizado dos fases de envejecimiento acelerado: la primera tenía el objetivo de acercar el material de cantera sin alterar (“sano”) a las condiciones reales del material puesto en obra y actualmente deteriorado; la segunda, efectuada después de aplicar los tratamientos sobre la calcarenita deteriorada, con el fin de determinar su grado de eficacia. Se ha podido comprobar que aunque, en general, todos los productos de tratamiento seleccionados (Tegosivin HL100, Silo 111, Estel 1100 y Tegovakon V) mejoran las propiedades del material frente al deterioro y apenas modifican sus parámetros cromáticos, el más eficaz es el Tegovakon V ya que es el que proporciona mejores resultados frente a los ensayos hídricos en este litotipo calcáreo.
Macroscopical morphology of deterioration of the stone in the cathedral of Guadíx/Spain
Alcalde, M.,Martín, A.
Materiales de Construccion , 1991,
Abstract: The main factors of deterioration that affect the Cathedral of Guadíx are of a natural origin, basically thermic and hydraulic, due to its great oscillations in temperature in Summer, the frequency of frosts in Winter and the rains. The lithotypes employed are mainly calcarenite of mean porosite and slightly more compact limestones from the quarries in the area, and marbles. The corresponding deterioration mechanisms are those of differential thermic dilatations caused by thermic jumps, especially in the more compact stones, those of increase in volume in capillaries and interstices, especially by freezing, and those of dissolution. The most serious deterioration indicators are fissures and spalling that affect the most carved elements and which have taken the greater part of the most aerated elements such as the pinnacles to a state to ruin. Los principales factores de alteración que afectan a la catedral de Guadix son de origen natural, fundamentalmente térmico e hidráulico, por sus grandes oscilaciones de temperatura en verano y por la frecuencia de heladas en invierno, y por la lluvias. Los litotipos empleados son principalmente calcarenitas de porosidad media y calizas algo más compactas, procedentes de canteras de la zona, y mármoles. Los mecanismos de alteración correspondientes son los de dilatación térmica diferencial originados por los saltos térmicos, en especial en las piedras más compactas, los de incremento de volumen en capilares e intersticios, sobre todo por heladicidad, y los de disolución. Los indicadores de alteración más graves son las fisuras y fragmentaciones que afectan a los elementos más labrados y que han llevado al estado de ruina a la mayor parte de los elementos más aireados como los pináculos.
Macroscopical morphology of deterioration of the stone in the Cathedral of Baeza, Jaen (Spain)
Alcalde, M.,Terreros, G. G.,Villegas, R.
Materiales de Construccion , 1998,
Abstract: The main factors of deterioration that affect the Cathedral of Baeza are of a natural origin, basically thermic and hydraulic. Two types of calcarenite were employed in the construction of the major part of this building: one 'franca" of medium porosity and another "viva" harder and more compact, both extracted from the quarries in the area. The most frequent mechanisms of deterioration are those bound to crystallization-dissolution and hydration-dehydration of salts, as well as freezing inside the pores. Fa ade-by-fa ade description of the deterioration indicators is provided; the most common ones tend to be fissures, grain disgregations and disjunctions. Los principales factores de alteración que afectan a la Catedral de Baeza son de origen natural, fundamentalmente de tipo térmico e hidráulico. Para la construcción se han empleado en su mayor parte dos tipos de calcarenita, una franca de porosidad media y otra más dura y compacta procedentes de canteras de la zona. Los mecanismos de alteración más frecuentes son los ligados a la cristalización-disolución e hidratación-deshidratación de sales, así como a los de heladicidad en interior de los poros. Se hace una descripción por fachadas de los indicadores de alteración, siendo los más frecuentes las fisuras, arenizaciones y disyunciones.
Macroscópical morphology of deterioration of the stone in the Cathedral of Almería/Spain
Alcalde, M.,Martin, A.
Materiales de Construccion , 1991,
Abstract: The prevailing winds in the area, associated with an important rising damp are the main natural factors of deterioration that affect the Cathedral of Almería. Certain unfortunate maintenance Jobs carried out as well as the bombardments and machine-gunning on the building during the Civil War can be indicated as anthropogenical factors of deterioration. The only lithotype used in the construction is a dolomitic limestone of high porosity from quarries near the city. The increase in volume in capillaries and interstices, related whith the presence of salts, and the dissolution, due to the great solubility of the natural magnesium salts which can produce dedolomitization of the stone, are the main deterioration mechanisms. This leads to indicators of deterioration with a typical morphology consisting of openings in all its manifestations (pitting, alveolar erosions and craters) especially on the high and low parts of the building where the wind and humidity, respectively, are more intense. The anthropogenical deterioration also has the shape of openings, such as the impact of bullets and obuses on the Southern facade and the grooves made for electric cables throughout the building. Diverse restorations have introduced tensions in the materials which have led to decohesions at different degrees (disaggregations, disintegrations and grain disgregations) in the interior of the temple and cloister. The building is in a state of deterioration of a certain significance which essentially affects its esthetics. The speed in the degrading process observed in some areas calls for action for its maintenance. Los vientos reinantes en la zona, asociados a una importante humedad ascendente, son los principales factores naturales de alteración que afectan a la Catedral de Almería. Pueden se alarse como factores antropogénicos de alteración ciertas desafortunadas labores de mantenimiento llevadas a cabo, así como, aunque con carácter episódico, los bombardeos y ametrallamientos sufridos por el edificio durante la guerra civil. El único litotipo empleado en la construcción es una caliza dolomítica de elevada porosidad procedente de canteras próximas a la ciudad. Los principales mecanismos de alteración son los de incremento de volumen en capilares e intersticios, ligados a la presencia de sales, y los de disolución, dada la solubilidad de las sales de magnesio de constitución, que pueden producir la desdolomitización de la piedra. Esto conduce a unos indicadores de alteración con una morfología típica consistente en huecos en todas sus manifestaciones: picados, alveolizaci
Macroscopical morphology of deterioration of the stone used in the cathedral whole of Granada/Spain
Alcalde, M.,Martin, L.,Bello, M. A.,Martin, A.
Materiales de Construccion , 1992,
Abstract: The main factors of deterioration that affect the Cathedral Whole of Granada are one of natural thermic origin due to the low temperatures during the winters and the higher thermic oscillations and those of anthropogenical origin: fundamentally the oxidation of metallic elements and atmospheric pollution due to burnt products. For this reason, the more important deterioration mechanisms are the freezing ones due to the expansion produced in the water retained inside the pores and microcracks, fundamentally in the architectonic elements with high expositional surface and in their shady orientation; the main indicators produced are fissuring and spalling. In this way, a lot of elements of Santa Pudia stone located in the Royal Chapel crenellations have disappeared and the rest are very deteriorated. The more compact Sierra Elvira stone used on the upper zone of the cornices has also been affected by the freezing mechanism, which starts with the microcracks produced by differential dilatations due to the thermic oscillations which made the water access easy. The iron corrosion and later expansion of the oxidation products has provoked the cracking and fissuring of many ornamental elements like balls, pinnacles, etc, and this situation has obliged their dismantling on the upper zones due to the danger to the public. The mechanisms of dissolution, crystallization cycles and Chemical action have led to abundant material loosening in the form of grain disgregations overcoats on the higher humidity zones, and formation of hollows (pitting, alveolar erosion, striations) in the zones more exposed to the winds. This situation is generalized in the lower zones of the monument, except on the main facade, and in the parapets and lower zones of the cornices. The grain disgregations are more important when biological crusts or unburned deposits exist, the latter being of major abundance on the surfaces near the Gran Vía and in its orientation. It is necessary to mention the pigeon dung deposits, very important in the main facade, with greater stetical repercussion. Los principales factores de alteración que actúan en el conjunto catedralicio de Granada son, uno natural de origen térmico, dadas las bajas temperaturas que se alcanzan en invierno, y las grandes oscilaciones térmicas que se registran durante gran parte del a o, y los de origen antropogénico, fundamentalmente los de mal uso de elementos de sujeción metálicos oxidables y los de contaminación atmosférica debida a productos de combustión. De esta forma, los mecanismos de alteración primordiales son los de helad
Macroscopical morphology of deterioration of the stone in the Cathedral of Cádiz, Spain
Alcalde, M.,Martín, A.
Materiales de Construccion , 1990,
Abstract: Two factors have determined the actual deterioration state of the Cathedral of Cádiz, one is natural and the other is anthropogenic. On one hand, the presence of salts conditioned by atmospherical environment and saline solutions of the rising damp; on the other hand, the vicissitudes suffered by the temple during its construction, having been unprotected for long periods of time both internally and externally the bad use of the building and the little maintenance carried out on it. The crystallization and dissolution, and salt hydratation and dehydratation mechanisms have provoked serious deteriorations in the foreign lithotypes: spalling in compact limestones, chipping and pulverizations in marbles; the autochthonous “ostionera", well-balanced in the medium, presents a good state of conservation. The interior of the Cathedral, contrary to the normal, is much more degraded than the exterior. Dos son los factores de alteración que han determinado el estado actual de alteración de la Catedral de Cádiz, uno natural y otro antropogénico. Por una parte la presencia de sales, condicionada tanto por el ambiente atmosférico como por la ascensión capilar desde el subsuelo de soluciones salinas; por otra, las vicisitudes sufridas por el templo durante su construcción, desprotegido del medio largos períodos de tiempo tanto interior como exteriormente, el mal uso del mismo y las escasas actuaciones de mantenimiento. Los mecanismos de aumento de volumen en capilares e intersticios ligados a la cristalización y disolución, e hidratación y deshidratación de sales, han provocado graves alteraciones en los litotipos foráneos, siendo los indicadores de alteración más típicos en esta Catedral las fragmentaciones en las calizas compactas, disyunciones y pulverizaciones en los mármoles, y eflorescencias de forma general; la autóctona ostionera, en buen equilibrio con el medio, presenta un buen estado de conservación. El interior de la Catedral, contrariamente a lo usual, se encuentra mucho más degradado que el exterior y su estado es tal que se hace difícil ya su recuperación.
Advanced Deterioration Diagnosis Model for Building External Wall Tiles  [PDF]
Sy-Jye Guo
World Journal of Engineering and Technology (WJET) , 2018, DOI: 10.4236/wjet.2018.62B001
Abstract:
In 1981 Taiwan entered a period of intense construction, meaning that today many buildings are more than 30 years old. Lack of maintenance has led to frequent safety incidents involving external walls. This study focuses on a deterioration diagnostic model for external wall tiles of aged buildings, using both stage 1 and stage 2 diagnostic methods. The visual test results are categorized based on impact on public safety, and renovation strategies are proposed. Stage 1 diagnosis mainly adopted the DER visual inspection deterioration assessment method. For enhance the accuracy, this research adopted the Infrared Thermal Imaging detection method to double confirm the visual inspection results. After producing an external wall tile Condition Indicator (CI). For stage 1 diagnostic results that fall in a gray area, stage 2 diagnosis was carried out using a tap tone test, followed by fast Fourier transform and pattern recognition to analyze the tapping results. Finally, the study provides a deterioration evaluation criteria for external wall tiles replacement recommendations and a standard operating procedure for deterioration diagnosis. The study also recommends directions for future amendment of regulations, and provides a basis of reference for the government in determining urban renewal, renovation and maintenance strategies.
An approach to the study of the fungal deterioration of a classical art material: Mastic varnish
Romero-Noguera,Julio; López-Miras,María del Mar; Martín-Sánchez,Inés; Ramos-López,José Miguel; Bolívar-Galiano,Fernando;
Electronic Journal of Biotechnology , 2010,
Abstract: mastic, one of the best natural varnishes, is frequently used as protective and finishing layer or as component of oleo-resinous media in paintings, both in the past and currently. however, this resin is affected by complex deterioration processes which can change its characteristics and thus the visual aspect of works of art. the alteration processes caused by radiation have been widely studied, but there is a lack of information on the biodeterioration of this natural product. in this paper, fungi from collections as well as from oil paintings of the fine arts museum of granada (spain) were inoculated onto slides covered with mastic. the samples, after an incubation period of 15 days, were analysed by gas chromatography-mass spectrometry (gc-ms) to identify the chemical changes undergone, and a visual monitoring of the samples was performed to determine the formation of mycelia onto solidified resins. major changes were detected in chrysonilia sitophila, phoma herbarum, and p. chrysogenum, showing evidence of alteration processes caused or favoured by these microorgamisms.
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