Abstract:The most significant damage faced by glazed architectural components in the Forbidden City is the large-scale detachment of colored glazes. We selected some standard glazed tubular tiles from Yan Xi Tang of Yang Xin Dian (Hall of Mental Cultivation) as the research objects, and analyzed the compositions, morphologies and thermal properties of the glazes and tile bodies. We also performed cyclic simulation experiments under different conditions in this study. We observed that drastic changes in environmental temperature and humidity caused the glazed-tile samples to undergo glaze detachment. In particular, greater glaze thickness and a larger difference in the properties of thermal diffusion and thermal expansion between the glaze and the body led to a faster detachment rate. This was most evident when the samples experienced “quenching”, i.e., when they underwent a rapid temperature drop from a high to a low temperature in a temperature-cycling process. The largest temperature drop rate of the glaze was observed when samples at a high temperature were placed into an ice water mixture in a freezing chamber. This sharp change in temperature caused an uneven distribution of tensile stress in the glaze and an uneven distribution of thermal stress at the glaze-body interface, resulting in the most severe detachment damage to the glaze. The simulated experimental conditions that best matched the damage to the glazed tile samples were the most similar to the high temperature/storm conditions in summer, implying that the high-temperature/storm conditions may be one of the main factors leading to glaze detachment in ancient buildings.

Abstract:To make up for the lack of research on conservation materials for murals in humid areas of south China, we evaluated the conservation effects of some materials used for mural surface reinforcement and fracture grouting under a simulated climatic condition of south China. Through evaluations of surface gloss, water resistance, aging resistance and other properties, we found that 1) 1.5% (mass fraction) RS1930 pure acrylic emulsion had better surface-reinforcing effect and 2) traditional lime added with ZB-SE-3A pure acrylic emulsion (about 3% of lime mass) and nano materials (about 2% of lime mass) demonstrated good strength, mildew resistance, water resistance and aging resistance, and was suitable as a fracture-grouting material for murals in humid areas.

Abstract:In order to study the reasons for and mechanisms of deterioration of stone sculptures at Mao Mausoleum, we characterized the contaminants and soluble salts collected from the sculpture surfaces using X-ray diffraction (XRD), scanning electron microscopy-energy dispersive spectrometry (SEM-EDS) and Fourier transform infrared spectrometry (FTIR), and also determined the ions of soluble salts and quantified their distribution using ion chromatography (IC). The results show that 1) gypsum crusts (CaSO₄·2H₂O) on “Horse Stepping on a Hun Soldier” was formed either by chemical reactions occurring on the sculpture surface due to deposition of atmospheric pollutants, or by capillary migration of soluble salts from underground water; 2) soluble salts containing Na₂SO₄, NaNO₃ and CaSO₄·2H₂O on the surface of “Monster Preying on a Sheep”, were mainly caused by capillary migration of soluble salts of underground water through the brick base to the stone matrix, resulting in repeated crystallization and dissolution on the sculpture surface according to environmental cycles of temperature and humidity. Soluble salts are known to cause stone deterioration in the form of lifting spalls, detaching scales and breakage of the internal material structure of stone sculptures. These are also the main diseases seen on the stone sculptures at the Mao Mausoleum.

Abstract:To effectively protect ancient Chinese buildings, based on the research achievements of an earlier paper, Shaking table tests of an ancient Chinese building with single layer gable and hip roof, the seismic performance of a model was studied under conditions of high-intensity earthquakes. The same model with the one in the first paper was built, and waves in horizontal directions, simulating the 1940 El-Centro earthquake, were applied to the model, with the intensity gradually being increased to a very high level. Experimental phenomena of different constituents of the model were analyzed and symptoms of damage were also investigated in detail. The results show that under high-intensity earthquake conditions, the column structure, the tou-kung, the beam system and the roof vibrate as synchronous motion as a slow sway. The main damage symptoms of the structure include deviation of column roots from their original positions, tenons being pulled out of mortises, cracks on tenon-mortise joints, deviation of parts of tou-kung from their origin positions, disconnection of the tie beam from its cushion board and collapse of filler walls, etc. However, the damage was not serious, nor did the timber structure collapse. The seismic performance of an ancient Chinese building under high-intensity earthquakes relates closely to its constituent characteristics.

Abstract:Organic materials, such as textiles found in tombs of the Western Zhou Dynasty at Zhouyuan Site, are usually in bad conditions because of the alkaline soils in the Central Shaanxi Plain. The contexts of these textiles are barely discernable for archaeological studies because these materials are often not recognized. Thus, it is quite important to identify these materials and study their archaeological implications. Based on the phytolith approach, textiles excavated from tombs at Zhouyuan Site in 2017 were identified as having been made from reeds (Phragmites communis). Referring to the records in ancient literature and the locations where the textiles were found in the tombs, we presume the textiles were used as mattresses in coffins or barriers above coffins to resist soils.

Abstract:From 2004 to 2006, the Archaeology Department of Zhengzhou University excavated Nanwa Site in Dengfeng, Henan Province. A heavily-weathered white necklace and ear-rings were found respectively from Tomb 2004M18 and 2004M26. The results of scanning electron microscopy (SEM) and X-ray fluorescence (XRF) spectrometry show that they both contain PbO-SiO₂ glass components. The dating results show that they are both from the Northern Song Dynasty. The two tombs are relatively small in size, but both have glassware as burial objects. To some extent, this indicates that, along with the maturation of the technology for making glass products, the group of consumer of glass products began to expand, increasing the consumption of glass products.

Abstract:In our study, we analyzed the structure and composition of corrosion products of a bronze Fang sample (dated to the Western Han Dynasty) unearthed at Dongtianpu Cemetery of Zhongxian County, Chongqing, using optical microscopy (OM), scanning electron microscopy (SEM) and Raman spectrometry. The composition and microbial community of the buried soil attached to the Fang were also analyzed using X-ray fluorescence (XRF) spectrometry and microbiological analysis technology. The results show that 1) the main corrosion products include malachite, cerussite, anglesite, pyromorphite, mimetite and cuprite; 2) the enrichment of phosphorus and chlorine can be seen obviously in the outermost corrosion layers; 3) phosphorus, sulfur and chlorine from the soil were found enriched on the bronze Fang, and copper, tin and lead of the bronze Fang diffused to the soil and 4) fungi such as Trichocomeceae, Penicillium and Aspergillus were detected in the soil attached to the bronze Fang.

Abstract:Nowadays, for restoration of Chinese paintings and calligraphy, there are more and more excellent ways to retain and restore original mountings with ancient styles, along with the broken painting or calligraphy itself. In our work, we restored a couplet by Wu Changshuo from Yixing Museum, and also preserved its original mounting. The calligraphy and the original mounting both had serious creases, breakage marks, or even cracks. The cover and the backing paper were aged and crispy. After analyzing the materials, diseases and characteristics of the calligraphy and the original mounting, with the aim of achieving the optimum effect of restoration, the calligraphy and the mounting were separated and then restored separately before being recombined. At the time of recombination, improvements and fine adjustments of the original mounting defects were also made so as to restore the original appearance, retain the elegant charm of the times and be conducive to future collection and conservation.

Abstract:Paper and paste are important materials for painting and calligraphy mounting. Their properties affect the overall beauty and longevity of mounting parts. Japan has inherited the traditional mounting style of China, but has also developed its own unique mounting materials—Japanese paper and ancient paste. Paper and paste with different properties are used in different stages of mounting, which reflects the inheritance and innovation spirit of traditional mounting culture. Successful experience with the combined use of ancient paste and Japanese paper could provide some reference relevant to the inheritance and innovation of traditional mounting techniques for Chinese paintings and calligraphy.

Abstract:In order to study the influence of rammed earth properties on rainfall erosion of the Great Wall of the Ming Dynasty in northern Shaanxi in a quantitative way, quantitative simulation experiments were conducted, using models. The results show that 1) under heavy rain or in rainstorms, low-density rammed earth performs dry-wet function, and the soil loss from scouring erosion is relatively lower; 2) under the same conditions, high-density rammed earth models exhibit mainly scouring erosion and partial collapse, and the soil loss from scouring erosion is relatively higher. The soil loss from rainfall erosion shows an exponential relationship with the density of rammed earth, and they show a positive correlation within the natural soil water content range. The study enriches rainfall erosion models of rammed earth sites and offers useful reference for further study of rammed earth site erosion mechanisms under multi-factor coupling conditions.

Abstract:In order to improve the preservation environment of cultural relics, Shenzhen Museum has established and implemented a preliminary preventive conservation system for cultural relics in the collection of its new pavilion (Shenzhen Museum of History Folk Culture). The project includes establishing a wireless monitoring system platform, improving the general preservation environment of cultural relics in exhibition halls and storerooms, regulating the microenvironment of special exhibition cabinets, configuring a variety of special cultural relic boxes, replacing existing display cases with independent high-quality exhibition cabinets in permanent exhibition halls, and establishing a monitoring and management mechanism for the preservation environment of the cultural relics. Thus, the preventive conservation capability and level of the museum are improved, and the influence of environmental factors detrimental to the safe preservation of cultural relics is reduced. This paper summarizes the process, mechanism, content, measures and related thinking of the project, which may be generally beneficial to the comprehensive and sustainable promotion of the preventive conservation of cultural relics.

Abstract:China has a great number of cultural relics with historical, scientific, social and economic value. The conservation of cultural relics gets strong support from the country, but only under conditions of reasonable allocation and utilization of resources can the conservation of cultural relics be truly realized. With changes in cultural relic conservation concepts in China, preventive conservation is becoming more and more important, and the relationship between the safety of cultural relics and their environment has attracted more and more attention. This article, which examines the relationship between cultural relics and their environment, divides the environment of cultural relics into three categories:natural, semi-exposed natural and artificial environments. Then, according to the needs of archaeological excavation, building preservation, cultural relic restoration and display, this article analyzes the mutual transformation of the three cultural relic environments and related problems. Recommended standards for the conservation environments of all kinds of cultural relics have been assigned in China on the basis of materials of cultural relics. These standards have played an important role in promoting the conservation of cultural relics in China; however, the existing conservation methods as well as the standards sometimes neglect the differences in their original cultural environments, resulting in the limitation of their applicability. By discussing the relationship between cultural environments and cultural relic status and the influences on cultural relics, this article advances strategies for the preventive conservation of cultural relics under different environmental conditions.

Abstract:The subject of our study was application of the sacrificial anode method to the conservation of reinforced concrete cultural relics. First, the current status of research and application practices of the sacrificial anode method at home and abroad were summarized. Research results of three aspects were categorized and analyzed; these included change of application objects, co-development of practice and research, and extension of applications. Then the feasibility of using the sacrificial anode method for the conservation of reinforced concrete cultural relics was studied. The application mechanism and design method for the conservation of reinforced concrete cultural relics using sacrificial anode method were elaborated on. Finally, using as a case study the Nanjing Yangtze River Bridge, application of this method with the aim of increasing the durability of the main arch rings of the double curved arch bridge was studied. On the basis of review and summary, a new opportunity for the conservation of reinforced concrete cultural relics strengthened with sacrificial anode method was put forward. The results could provide some references for the application of sacrificial anode method in the conservation of reinforced concrete cultural relics.

Abstract:Cultural relics carry rich historical and cultural information. At the time of archaeological excavations, the extraction of fragile cultural relics such as silk, paper and mural paintings is the focus of some archaeological work. In order to ensure complete extraction of fragile remains without loss of important archaeological data, it is necessary to temporarily reinforce the fragile remains at the archaeological excavation site. As a new type of temporary consolidant for extraction, menthol has been successfully applied at archaeological sites. This paper summarizes the basic properties and usage of menthol and also introduces some cases of its application to the conservation and restoration of cultural relics.

Abstract:Due to the characteristics of relatively enclosed museum space, the presence of crowds, the coexistence of people and cultural relics, etc., both people (staff and visitors) and objects (culture relics or artworks) should be considered when disinfectants are used. In terms of measures for people, the document, Guidelines for the Use of Disinfectants, has adequately explained the scope of precautions to be taken when using disinfectants. The discussion in this paper focuses only on three aspects of measures to be taken for culture relics:1) classification of cultural relic materials from the perspective of their scientific and technological conservation; 2) classification of disinfectants according to active ingredients, and significant chemical characteristics of disinfectants that may damage cultural relics and 3) mechanisms of damage and the consequences of using disinfectant on cultural relics. In the special stage of epidemic prevention and control, museum staff must have a comprehensive understanding of the characteristics of various disinfectants in order to ensure the safety of cultural relics. Using disinfectants in a rational and regulated way and preventing improper use from causing damage to cultural relics are essential tasks for the preventive conservation of culture relics.