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1.
Monika Slavíková František Krejčí Jan Žemlička Michal Pech Petr Kotlík Jan Jakůbek 《Journal of Cultural Heritage》2012,13(4):357-364
Stone consolidation is one of the major restoration treatments used for historical monuments preservation. A natural stone is a complicated heterogeneous porous system making the process of consolidation dependent on many variables. In practical restoration aims, for a given stone type, the selection of a suitable consolidant and consolidation conditions therefore remains a complex issue. The impregnation depth is a key factor for the assessment of the treatment efficiency. The combination of state-of-the-art hybrid pixel semiconductor detectors with newly available micro-focus X-ray sources makes possible to apply X-ray radiography, an ideal non-destructive tool, for penetration depth monitoring. In this study, high-resolution X-ray radiography is used for monitoring the penetration depth of organosilicon consolidants in the Opuka stone. The penetration depth has been evaluated in relation to the time of consolidation, stone porosity and consolidation mixtures properties. The exact influence of the X-ray contrast agent on the consolidation depth has been investigated as well. The information obtained provides supplementary knowledge on the suitability of investigated products for the treatment of this type of stone. In our study, the capabilities of X-ray radiography have been demonstrated on X-ray radiography simple projections, high-resolution computed tomography (CT) as well as on the dynamic processes monitoring. The results thus can serve also as an instrumental and methodological example applicable for consolidation monitoring of other stone types. 相似文献
2.
《Journal of Cultural Heritage》2009,10(2):214-221
Consolidants based on tetraethoxysilane (TEOS) have been widely used for the consolidation of decaying stone heritages. These products polymerize within the porous structure of the decaying stone, significantly increasing the cohesion of the material. However, TEOS-based consolidants suffer from practical drawbacks, such as crack formation of the gel during the drying phase due to the developed capillary force, which is typical for TEOS-based consolidants. We have prepared new consolidants TEOS-based consolidants containing flexible (3-glycidoxypropyl) trimethoxysilane (GPTMS) and silica nanoparticles in order to reduce capillary force development during gel drying, and have characterized them for the application of stone consolidants. Different sizes of silica nanoparticles were used, which were smaller than the pore size of the tested stone. The properties of the TEOS/GPTMS/nanoparticle composite solution were compared with those of the commercial products Wacker OH and Unil sandsteinfestiger OH 1:1. The gelation time was similar to that of commercial consolidants, and the TEOS/GPTMS/nanoparticle solution was stable over a period of up to six months. The contact angle of the surface increased with the addition of the nanoparticle, as well as with the addition the GPTMS, which is higher than that of commercial Wacker OH. The addition of a nanoparticle, as well as GPTMS having flexible segment, provided a crack-free material, while the gels obtained from the commercial consolidants exhibited cracking. 相似文献
3.
This article demonstrates the importance of treatment application procedures on the consolidation effectiveness obtained by comparison of the results obtained using three different consolidants on four carbonate stone types, and proposes a general methodology for assessing the potential effectiveness of consolidants in laboratory conditions. It stresses the relevance of taking into account the treatment methodology, given the influence application protocols can have on the overall behaviour of the consolidated material. Several mechanical properties were assessed to demonstrate this influence on the performance of the consolidant. The results demonstrate that the strengthening action achieved with a specific product can only be defined in a strict relation to the treatment protocol used to produce it. The results also contribute towards the definition of standard testing protocols on stone consolidation. The application of a consolidant by direct contact capillary absorption is a reliable procedure and the results are easier to interpret than others obtained by brushing or by full immersion, thus making this procedure a good candidate for an eventual standard laboratory assessment method of the consolidation action of any specific stone/consolidant combination. This study also showed that the best test method to assess the strengthening action of stone consolidants in soft stones is DRMS (Drilling Resistance Measuring System). Moreover, the collection of longitudinal ultrasound velocity profiles determined in stones specimens treated by contact capillary absorption was shown to be a useful non-destructive method to assess the depth of the strengthening action achieved. 相似文献
4.
《Journal of Cultural Heritage》2000,1(2):127-132
The penetration of water in rock materials is the main cause of deterioration of stone surfaces exposed to rainfall. Their protection is generally achieved using water-repellents, in order to reduce the absorption of water. Nuclear Magnetic Resonance Imaging (MRI) provides a new tool to visualize the presence of water inside the stone and, hence, the performance of hydrophobic treatments. This technique can also give indirect information on the distribution of the hydrophobic product inside the rock. 相似文献
5.
《Journal of Cultural Heritage》2014,15(1):10-17
When timber elements in heritage buildings are moderately degraded by fungi and assuming underlying moisture problems have been solved, two actions can be taken: i) use a biocide to stop fungal activity; ii) consolidate the degraded elements so that the timber keeps on fulfilling its structural and decorative functions. The aim of this work is to investigate the mechanical performance of maritime pine wood degraded by fungi after being treated with a biocide followed by impregnation with a polymer product. Three commercially available products were used: a boron water-based biocide, an acrylic consolidant and an epoxy-based consolidant. Treated and consolidated specimens were subjected to mechanical tests: axial compression test (NP 618), static surface hardness (ISO 3350) and bending test (NP 619). Sets of replicates were subjected to an evaporation ageing test (EN 73) after application of the products and also tested for mechanical behaviour. An increase in mechanical strength was observed for both consolidants with no significant influence from the previous use of biocide product. The specimens subjected to ageing showed a slightly better general mechanical performance. 相似文献
6.
《Journal of Cultural Heritage》2014,15(4):432-440
The analysis of environmental risk in historical cities facilitates the development of conservation strategies that can minimize the deterioration of historical heritage sites. Risk maps built with GIS software provide information about the probability of the main hazards in a region, and is a very useful tool to identify, evaluate and prioritize the restoration budget of a city in order to manage preventive conservation. In this paper, new methodologies are applied based on the vulnerability matrix and its relationship with static and structural factors, climate conditions, air quality and social agents. This technique has some obvious advantages in the application of risk analysis for cultural heritage conservation, such as the capability of simultaneous risk assessment and geographical references. The vulnerability study implies an on-site diagnosis analysis and requires an adapted protocol for archaeological heritage. The validation of this methodology was carried out in the historical town of Merida (Spain) with a GIS application (ArcGIS software), where the main monuments of this UNESCO World Heritage site were studied. 相似文献
7.
《Journal of Cultural Heritage》2000,1(1):29-36
This paper presents the first investigation on the remote sensing of stone monuments by fluorescence lidar. The advantages of this technique are manifold and can lead to a fast, extensive and inexpensive control of the stone cultural heritage. The experiments were carried out in both the laboratory and the field, and include the survey of stones coming from different quarries, of epilithic photosynthetic biodeteriogens and of a monument, the Parma Baptistery. The results constitute a first step towards a non-destructive spectral analysis of stone monument surfaces. 相似文献
8.
《Journal of Cultural Heritage》2014,15(4):352-358
The diversity of volcanic tuff buildings standing in Western Mexico is large, therefore, it was considered relevant to evaluate and synthetize different stone consolidants that could be applied in the regional weather conditions and renew the stability of those buildings; since the commercial products are developed and tested in foreign countries, and in some cases, when applied under the weather conditions of Mexico, the results differ from those reported. For the altered tuffs from Santa Mónica's Church in Guadalajara, Mexico, the deterioration mechanism of the local tuff was determined, thus a silicate and aluminosilicate consolidants were synthesized by the sol-gel method and applied to altered tuffs in order to evaluate their performance from structural to macroscopic level. 相似文献
9.
《Journal of Cultural Heritage》2002,3(2):117-125
The recent development of a new drilling machine in the framework of the EU project HARDROCK brought some interesting perspectives for the characterisation of decay profiles, for tracing old consolidating treatments and for evaluating new consolidants. The equipment executes a drill hole, typically 5 mm in diameter, down to 5 cm, under precisely defined and controlled drilling conditions. The output is a graph of force versus depth. The instrument can be transported and operated in situ. The operator defines the drilling rotation speed and the advancing rate and the instrument registers the force required for executing the hole under those strictly defined conditions. This paper presents some data taken from a laboratory study on consolidants which demonstrate that the equipment has a very high discriminating power for detecting the presence of consolidants. Clear differences among some typical consolidants were detected, both in the strength increase and in the penetration depth. They also show that the average drilling forces present a fairly good correlation with bending strength, in spite of the fact that full consolidation of the tested specimens was not possible with all consolidants. The in situ study of Porta Especiosa has shown that the instrument was able to identify the presence of decay events at several depths, in a way that no other known method can do. The identification of the presence of old treatments was demonstrated with total guarantee. 相似文献
10.
11.
《Journal of Cultural Heritage》2014,15(4):441-447
Academic studies concerning how climate influences Asian heritage are rare. The object of this study was to utilize the concept of heritage climatology together with a spatial analysis approach that includes respective climate parameter risks to cultural heritage sites. The study area, Tainan City, Taiwan, is in a subtropical zone south of the Tropic of Cancer. Tainan has nearly 300 hundred years of rich history and a multicultural background. This study used maps to gain information about potential climactic threats to Tainan's cultural-historical legacy. There are four kinds of map that use ArcGIS to analyse and demarcate regions not only by climate parameters but also by risk to heritage. These four types of map are climate maps, heritage climate maps, heritage maps and heritage risk maps. Climate maps give the short- to medium-term general status of the climate in Tainan City and thus served as the foundation of the other maps used in this study. Heritage climate maps give data concerning index factors that influence wood and stone materials. Heritage maps show locations of cultural heritage sites on an administrative map and categorize them according to their historic value. Heritage risk maps use accumulated calculations to superimpose the heritage climate map onto the heritage map in order to evaluate the risks to heritage sites in certain areas and categorize the levels of risk. Heritage sites in mountainous areas generally need to be protected from heavy rain, whereas downtown city environments, due to the urban heat island effect, require better protection against heat and cracking. By comparison of our field study results and climate risk maps, we found that in urban areas wooden materials have a higher risk of structural cracking, colour fading and bio-degradation, while coastal areas have a higher risk of weathering of stone materials. 相似文献
12.
Ramón Zárraga Jorge Cervantes Carmen Salazar-Hernandez George Wheeler 《Journal of Cultural Heritage》2010,11(2):138-144
Hybrid stone consolidants prepared from tetraethoxysilane (TEOS) and α,ω-hydroxyl-terminated polydimethylsiloxane (PDMS-OH) have been considered as one of the most promising approaches to improve the effectiveness of traditional alkoxysilane-based formulations. They have emerged as response to the negative reports commonly found in the literature: the resulting silica gel phase (SiO2) tends to develop fractures and fissures inside the stone as the gel shrinks during the drying stage. In this work, we employed SEM, solid-state 29Si NMR spectroscopy and compressive tests to characterize SiO2-PDMS hybrid gels. We report the morphological characteristics exhibited by gels prepared in vitro and in situ. It was found an appreciable reduction of gel fracture for hybrids prepared from 5% w/w of PDMS. As TEOS polycondenses, PDMS-OH is chemically incorporated into the gel matrix via Si-O-Si bonds. The inclusion of these elastic chains provides the necessary flexibility to resist the stress imposed by capillary pressure. Additionally, an important hydrophobic character is imparted to the stone. 相似文献
13.
通过多个历史文化名城的相关保护规划文本、地方保护条例(办法)以及地方规划编制技术导则的分析,对历史文化风貌区的地方实践进行总结。"历史文化风貌区"较历史文化街区具有更丰富内涵与复杂性特征,保护规划过程中应注意识别"历史文化风貌区"中出现的新类型与内部价值要素,在探索和完善地方历史文化遗产保护体系的前提下,秉承不同于历史文化街区的保护思路,探索差异化的、量体裁衣式的历史文化风貌区保护方法。 相似文献
14.
《Journal of Cultural Heritage》2014,15(6):595-601
Epoxy resins, widely used in conservation, still remain controversial materials. Considering some of the drawbacks that currently limit the application of epoxy consolidants, we present the application of the cationic ring opening polymerization as a novel method to cure the epoxy monomer in the restoration field. The cationic polymerization was carried out through a redox system based on the reduction of the iodonium salt in the presence of ascorbic acid catalyzed by a copper salt. The use of this initiator system for carrying out a suitable consolidant for lime plaster is considered. First, the film properties of the cured films were investigated. Then, the formulation was applied on a sample of plaster and its compatibility was verified. Its effectiveness as a consolidant product is explored through the evaluation of chromatic changes, mechanical strength, morphology of the re-aggregated material, and changes of the surface properties. 相似文献
15.
在乡村振兴的目标下,建成遗产该如何保护和存续在许多国家均是难题。通过追溯英国处置乡村中的风土建筑这一建成遗产的重要组构部分的整体特点,对其价值认知、保护历程及规划体系的形成,进一步结合科兹沃尔德乡村保护案例的规划政策分析,从三个方面分析了英国风土建筑保护的策源力。即包括贵族乡绅在内的精英阶层对乡村自然景观营造和保护旨趣一直有其社会传统性;赞美自然和乡村生活的浪漫主义者进一步通过包含风土建筑在内的英国风景建构为英格兰的民族身份认知物;英国作为工业革命的产生地,较早开始对工业文明的进程带来的后果进行反思,保护乡村的建成遗产及其整体环境作为善性立法和公共利益优先的原则的体现,并较早地通过制度建立被纳入正当化、合法性的保护框架中。最后指出英国社会普遍达成的有关风土建筑及其文化地景整体性保护的共识与规划制度的配合是英国乡村大范围的建成遗产能够被成功保护的关键所在。 相似文献
16.
Domenica Paoletti Dario Ambrosini Stefano Sfarra Fabio Bisegna 《Journal of Cultural Heritage》2013,14(2):116-121
Conserving architectural heritage usually requires a multidisciplinary approach involving a variety of professionals and organizations. Since the evaluation of the state of conservation of historical buildings using destructive techniques should be avoided to prevent the integrity of the cultural heritage, the development of non-destructive and non-contact techniques is very important. InfraRed (IR) thermography is a non-destructive powerful tool for fast and accurate building diagnostics. In the investigation of historical structures, where a restoration or conservation treatment can cause irreversible damage to the structure, it is considered to be of most importance. A campaign of thermographic surveys were conducted on a large part of the historical cultural heritage of L’Aquila and its surroundings. In this paper we present the results of the study for the Church of Santa Maria ad Cryptas (XIII century), one of the most ancient buildings in the surroundings of L’Aquila and one of the best examples of Gothic art in Abruzzo, with the aim to evaluate the correspondence between the damage induced by the earthquake and the previous thermographic results, in order to validate the effectiveness of thermography and its role in preventive diagnosis. 相似文献
17.
In this paper, the threat posed to cultural heritage by landslides and avalanches is analysed for two communities (Ushguli and Mulakhi) in the Upper Svaneti region in Georgia. The vulnerability of 60 cultural heritage objects has been evaluated through a conservation calculation based on an existing methodology using a State of Conservation Index (SCIx), which served as an input in a Spatial Multicriteria Evaluation (SMCE). Factors that are considered important for the occurrence of landslides (slope, landcover, lithology and drainage density) and snow avalanches (slope, insolation, slope curvature and landcover) have been used to generate a susceptibility map. A qualitative risk assessment was carried out by combining susceptible areas and cultural heritage objects. As there were very limited historical data available on the occurrence of landslides and snow avalanches, a combination of local and expert knowledge has been used to extract information on both cultural heritage and natural hazards. Existing management plans were also analysed to evaluate how natural hazards could be incorporated. Finally, some recommendations are given related to the analysis of the impact of natural hazards on cultural heritage in Georgia. 相似文献
18.
山东地区文化遗产保护过程中,社区内外民众积极参与、通力合作已经成为文化遗产保护中必不可少的力量。社区内部民众的主动参与,从确立社区民众的文化自觉、完善社区民众的参与机制、注重对社区传承人的保护和拓展文化遗产产业链来实现。社区外部民众的积极参与,从提高外部民众参与积极性、保障外部民众知情权力、创新外部民众参与合作手段和注重外部民众的教育效果来实现。 相似文献
19.
《Journal of Cultural Heritage》2014,15(5):490-498
Assessment of multi-leaf stone masonry in earthquake-prone areas is mostly related to the evaluation of its texture, morphology, leaf detachment and structural cracking due to previous seismic activity, as well as disintegration due to material deterioration. For the plastered masonry with heritage or artistic value (paintings, frescoes etc.), both the type of structure and the extent of damage should be characterized with minimal interference to the structure, which could be overcome solely by non-destructive testing (NDT). However, due to the complexity of plastered multi-leaf masonry structure, the performance of well-known NDT methods could be significantly worsened. Therefore, as a prerequisite for applying NDT on multi-leaf stone masonry in practice, a validation process should be carried out. In this study, complementary ground penetrating radar (GPR) and infrared (IR) thermography measurements on plastered laboratory three-leaf stone masonry walls were performed. Apart from assessing the wall texture and morphology with the type of connection between the leaves, detection of gradual plaster delamination and crack propagation while subjecting the walls to an in-plane cyclic shear test was taken into account. The results showed that GPR could successfully visualize header stones passing through the whole depth of the specimen. The masonry texture behind the plaster could be well resolved by both methods, although GPR near-field effects worsened its localisation. For the detection of plaster delamination, IR thermography outperformed GPR by detecting delamination as small as 2 mm as well as structural crack patterns, whereas GPR only detected delamination larger than 8 mm. It was shown that the performance of both methods for defect detection could be further improved by image fusion based on unsupervised clustering methods. 相似文献
20.
Francesca Becherini Adriana Bernardi Elisa Frassoldati 《Journal of Cultural Heritage》2010,11(4):46-476
The microclimatic analysis of the Petrarca's tomb in Arquà Petrarca, Padua (Italy) was performed to assess the suitability of a closed environment located outdoors respect to the conservation requirements of heritage materials. Results showed that the thermo-hygrometric conditions inside the tomb were not suitable for the conservation of organic materials, like bones and wood. The orientation (north or south) was the main responsible for the different damage features of the two sides of the wooden case housing the human remains inside the tomb. Technical solutions were finally implemented to improve the conservation conditions, thus avoiding further damage. 相似文献