• Journal of Conservation Science
• /
• v.24
• /
• pp.23-36
• /
• 2008

The stone Buddhas and Shrine of Unjusa temple (Korea Treasure No. 797) in Hwasun formed in Koryo Dynasty are unique style which the Buddha faces each other the back parts of south and north within the stone Shrine. The stone Buddhas and Shrine are highly evaluated in historical, artistic and academic respects. But, the stone properties have been exposed in the open system various aspects of degradations weathered for a long time without specific protective facilities. The rock materials of the stone Buddhas and Shrine are about 47 blocks, and total press load is about 56.6 metric ton. The host rocks composed mainly of white grey hyaline lithic tuff and rhyolitic tuff breccia. In addition, biotite granite used as part during the restoration works. The chemical index of alteration for host tuffaceous rocks and the replacement granites range from 52.1 to 59.4 and 50.0 to 51.0, respectively. Weathering types for the stone Buddhas and Shrine were largely divided with physical, chemical and biological weathering to make a synthetic deterioration map according to aspects of damage, and estimate share as compared with surface area. Whole deterioration degrees are represented that physical weathering appeared exfoliation. Chemical weathering is black coloration and biological weathering of grey lichen, which show each lighly deterioration degrees. According to deterioration degree by direction of stone Buddhas and Shrine, physical weathering mostly appeared by 39.1% on the sorthern part, and chemical weathering is 61.2% high share on the western part. Biological weathering showed 38.3% the largest distribution on the southern part. Therefore, it is necessary to try hardening for the parts with serious cracks or exfoliations, remove secondary contaminants and organisms through regular cleaning. Also necessary to make a plan to remove moisture of the ground which causes weathering, and estimate that need established and scientific processing through clinical demonstration of conservation plan that chooses suitable treatment.

• Journal of Conservation Science
• /
• v.32 no.3
• /
• pp.437-448
• /
• 2016

Studies on vulnerability of cultural heritage and adaptation strategy to worldwide climate change have been actively carried out in advanced countries since the late 20th century, and this established a valid research methodology and piled up climate and deterioration dataset in the field of climate change. Meanwhile, we still have tasks to acquire related scientific data despite referencing political researches in Korea. Applying Korean future climate to impact analysis, deterioration of Korean stone heritage is likely prospected to change into complexity in terms of physical, chemical and biological weathering that may bring impacts on conservation business and administrative field of cultural heritage. Further studies will ensure detailed implication of climate change impact on Korean stone heritage by means of down-scaling analysis of areas to local scale and dataset frequency to an hour. It is important to sort out capability and vulnerability of the stone heritage to future environment, and to make an adaption and prevention strategies.

• Journal of the Korea Furniture Society
• /
• v.23 no.3
• /
• pp.324-331
• /
• 2012

The domestic pine was used to investigate the change of specific gravity, moisture contents, color and anatomical structure by accelerated weathering test (AWT). According to visual inspection, a few knot separation and looseness as well as considerable surface discoloration was found out. However, the crack and split of surface texture have been never occurred till the last step of AWT. On the whole, as the time of accelerated weathering test has increased, the specific gravity has decreased. Finally, after the 9th week of AWT, the specific gravity was 0.38 that reached to 82% compared to the control specimen. In case of moisture content (MC), it showed rising trend in its early stages, however, after 3th week of AWT it have displayed steady state. A deterioration of cell-wall components was not remarkably observed by scanning electron microscope (SEM), however the ray fractures of AWT specimen were observed more than those of control specimen. The full fracture of epithelial cell around resin canal was observed by optical microscope. The fracture of ray of 2th cycle AWT specimen was first, followed by 1th week and control group. A distortion of tracheid for early spring wood and fracture of epithelial cell were generally observed by a similar level, regardless of duration time of AWT. Therefore, it is obvious that increasing duration time of AWT does not affect the deterioration of micro-structure for wood members from this study. Although a considerable change of anatomical properties was not found, there is a need of further research to understand how will the changes of specific gravity and MC on the physical properties of wood member.

• 보존과학연구
• /
• s.24
• /
• pp.5-28
• /
• 2003

Stone has been one of the most intensely studied materials in conservation. Understanding the deterioration of stone needs various knowledge in different mineralogical and physical characteristics and its weathering response under different climate and environment. The alteration and weathering of stone is affected by natural or artificial elements whether they are physical, chemical or biological damaging factors. It can be said that the bio deterioration of stone is coupled with every environmental factors, which induce decomposition of stone structure, either directly or indirectly as a form of catalysis. Many elements contribute to the deterioration of stone monuments and other objects of cultural value such as pagoda, stature of Buddha, etc. This report concentrates on the action of biodeteriorative factorsincluding bacteria, algae and higher plants. Preventive and remedial methods and a selection of chemical treatments are also described.

• Conservation and Restoration of Cultural Heritage
• /
• v.1 no.1
• /
• pp.29-37
• /
• 2012

The West Stone Pagoda at Gameunsaji Temple Site constructed in the 7th century is mainly composed of dark grey dacitic tuff bearing small numerous dioritic xenoliths. These xenoliths resulted in small holes due to differential weathering process from the host rocks. Physical strength of the pagoda was decreased due to weathering and damage caused by petrological, biological and coastal environmental factors. The southeastern part of the pagoda was extremely deteriorated that the rock surface showed exfoliation, fracture, open cavity, granular decomposition of minerals and salt crystallization by seawater spray from the eastern coast. The stone blocks were intersected by numerous cracks and contaminated by subsequent material such as cement mortar and iron plates. Also, the pagoda was colonized by algae, fungi, lichen and bryophytes on the roof rock surface and the gaps between the blocks. As a result of ultrasonic test, the rock materials fell under Highly Weathered Grade (HW) or Completely Weathered Grade (CW). Thus, conservational intervention is essentially required to prevent further weakening of the rock materials.

• Corrosion Science and Technology
• /
• v.8 no.3
• /
• pp.116-118
• /
• 2009

Korea Institute of Construction Materials founded Seosan Outdoor Exposure Test Site 2005 at Korea, which is a part of Worldwide Exposure Network (WEN). To evaluate the test site along with other exposure test sites, three different types of paints have been under real time weathering conditions at three major weathering test facilities around the world. Using these test specimens several spectroscopic experiments along with physical tests have been performed. Also acceleration tests have been performed using the same paints. The correlation of weathered paints among three different test facilities and accelerated test results has been compared. From the results the reliability of Seosan Weathering Test Facility and reasonable life time prediction tests are discussed.

• 보존과학연구
• /
• s.33
• /
• pp.57-67
• /
• 2012

The Uiseong Tapriri Five-Storied stone pagoda has occurred exfoliation, granular disintegration and discoloration by physical and chemical weathering factors with the major deterioration occurring due to efflorescence by salt. According to the results of SEM-EDS and X-ray diffraction analysis, salts consists of gypsum, taranakite. Artificial salt weathering tests were carried out using the same type of rocks as those in the stone pagoda. The test results showed that efflorescence occurred on the surface of the rock, and that exfoliation and granular disintegration occurred inside the rock due to salt crystallization.

• Journal of the Korean institute of surface engineering
• /
• v.47 no.2
• /
• pp.57-62
• /
• 2014

The biogas holder is composed of an outer membrane and an inner membrane which are subject to outdoor exposure and gas exposure respectively. The influence of weathering conditions on the photo-degradation of a biogas holder was investigated. Tests were performed under three different methods - outdoor exposure tests (Seosan, Arizona), accelerated tests (Xenon-are lamp) with the outer-membrane of biogas. Moreover, the changes in the aging process were monitored using color difference, gloss, the contact angle and an optical microscope. Changes in physical properties, such as decrease reduction in gloss, decrease in the contact angle, increase in color difference were observed in the aging process. The comparison between membrane 3B, 4B and membrane 5B under xenon-arc were discussed. Membrane 5B was very sensitive to ultraviolet (UV) ray. There were many difficulties in the outdoor exposure test due to acid rain, dust, and stain resistance.

• Journal of The Geomorphological Association of Korea
• /
• v.25 no.3
• /
• pp.19-42
• /
• 2018

In this study, we surveyed weathering progressing aspect by major elements variation and rock hardness by using XRF analysis, schmidt hammer, and thin section analysis. This observation suggested that the weathering process is likely to develop differently according to microstructural characteristics. R-value on the inside wall are lower than those on the outside. Also, the shadier the environment was, the closer it was to inshore areas, the R-value appeared to be lower. The movement of the elements such as Ca, Na and K shows that feldspar is hydrolyzed and can form salt crystallization like a gypsum or halite when they combine with the elements such as S or Cl. It proved a high CaO, $Na_2O$ and $K_2O$ content on flaking inside wall and rock meal. The exfoliation was mainly observed along the shady backwall and ceiling of tafoni. This helped in predicting the growth of tafoni as well as the direction of its progress.

• Journal of Conservation Science
• /
• v.34 no.3
• /
• pp.167-177
• /
• 2018

The Bayon style Avalokitesvara statue from the $13^{th}$ century Angkor period is on display at the Cambodia Angkor Conservation Office. This statue is composed of dark green felthspathic greywacke, the surface of which has been shown light brown discoloration, detected calcite crystallization. As a result of condition assessment, the statue was damaged due to overlap scaling and cracking. Ultrasonic tests have investigated remarkable physical weathering area, flaking and fragmentation in lower velocity. The physical condition of the statue requires a conservation method that improves the binding power. To protect against salt weathering and to ensure physical stability, new conservation material composed of mixed ethyl silicate and sandstone powder similar to that composing the statue was created. The material affected by damage was removed and replaced with the new conservation material.