• Journal of Conservation Science
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• v.11 no.1 s.14
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• pp.1-14
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• 2002

After the construction (1398 year at first, secondarily reconstructed at 1448 year), the Soongryemoon (South Gate) had been preserved to late 19c without large damages. The present shape of the gate have been kept after the repairments of two times (1953, 1963). However, the rocks constituting the walls of the gate have been strongly weathered, exfoliated and cracked due to severe changes in the environment as traffic increase, air pollution and the subway which may seem also to cause the structural unstability. The rocks composed of the walls of the gate are almost of granites. On the rocks such deteriorations as onion structure, surface exfoliation, cracks, and edge breakout are developed. These deteriorations may be caused genetically by strong weathering, differential load due to possibly structural unstability, impact and unknown reasons. For the establishment of conservation plan, the factors of these deterioration phenomena and structural unstability must be quantitatively analyzed and diagnosed in detail.

• Journal of Conservation Science
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• v.30 no.4
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• pp.447-456
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• 2014

This study is mainly about materials that are used in Sungnyemun gate's dancheong to find causes of dancheong's damage such as desquamation and peeling off. 12 kinds of pigments' components which are used in dancheoong are analyzed. Except for Hobun and Seokganju, the pigments are artificial. Samples are made with different conditions of adhesives and the rate of binder. To estimate promotion weathering test, adhesives are applied in a different order. Desquamation and peeling off presented especially when different adhesives are used on dancheong and also, generally the layer thickened.

• 보존과학연구
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• s.33
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• pp.57-67
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• 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 Conservation Science
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• v.19
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• pp.57-66
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• 2006

The rock consisting the Naju-Dongmunoi-Seogdanggan (Stone Stele)(Treasure number 49) is biotite granite of medium to coarse grains which might be taken from nearby area. The rock is mainly composed of quartz, plagioclase, alkali feldspar and biotite. Due to strong weathering grail peel-off and surface exfoliation are well developed. The rock surface is changed into pale brown or pale black colors according to weathering, organism and weathering product of iron band. Major deterioration phenomena are grain peel-off, surface exfoliation, cracks and damage which may be originally classified into weathering, effect of weathering product of iron band, organisms, structural unstabilities and impact.

• Journal of Conservation Science
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• v.27 no.4
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• pp.357-369
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• 2011

The Bongamsa Jeongjindaesa Wonotap Pagoda (Treasure No. 171) constructed in the 10th century composed mainly of leucocratic granite with feldspar phenocryst. The major rock-forming minerals are quartz, orthoclase, plagioclase and some biotite. This pogoda is highly damaged physical weathering which are break-out, flakes, exfoliation and cracks. As a result of the infrared thermography on the surface of the pagoda, internal exfoliations occurred to cracks. Also, P-XRF analysis showed that Fe, S, Ca and Mn of concentration were so high in the discoloration parts. The coated part of red pigment has a high five times in Fe content than the fresh rock surface. This result suggests that material of red pigment is hematite. Ultrasonic velocity of the stone properties were from 831 to 2,457 m/s, but it measured velocity of less than 1,000m/s in part of damaged area. Therefore, we suggest for safety conservation for weathered parts of the pagoda, that is in want of rejoin and consolidation treatment about serious damage parts.

• Journal of the Korea institute for structural maintenance and inspection
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• v.10 no.5
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• pp.121-129
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• 2006

This study look into the mechanisms of growth and magnification of the cracks and delamination in the pre-cracked RC beams repaired with carbon fiber sheets. The experimental parameters were loading type, loading speed and crack. In the experiments, it was confirmed that a failure of beams began with development and propagation of the stepped delamination in the below the loading point due to the rapid change of shear force, but mechanisms of the failure were not influenced with loading type, loading speed and pre-cracks. Particularly, in the case of beams having the pre-cracks, growth of crack concentrated at the special crack below the loading point and led to failure of the beam by delamination due to magnification of crack.

• Journal of Conservation Science
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• v.18 s.18
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• pp.19-32
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• 2006

The stone pagoda of the Bunhwangsa temple made by piling small brick-shaped stones. The major rock forming stone bricks are andesites with variable genesis. Rock properties of the pagoda roof stone suffer partly including multiple peel-offs, exfoliation, decomposition like onion peels, cracks forming round lines and falling off stone pieces. The stylobates and tabernacles in all the four directions the pagoda are mostly composed of granitic rocks. Those rock properties are heavily contaminated by lichens and mosses with the often marks of inorganic contamination by secondary hydrates that are dark black or yellowish brown. Within the four tabernacles and northern pagoda body situated to relatively high humidity. There are even light gray precipitate looking like stalactites between the northern and western rocks of the body Their major minerals are calcite, gypsum and clays. The stone lion standing in the southeast and northeast side are alkali granite, while that in the southwest and northwest lithic tuff. Total rock properties of the pagoda are 9,708 pieces, among the all properties, fractured blocks are 11.0%, fall out blocks are 6.7% and covered blocks by precipitates are 7.0%, respectively. The pagoda has highly deteriorated the functions of the rock properties due to physical, chemical and biological weathering, therefore, we suggest that this pagoda has need to do long term monitoring and synthetic conservation researches.

• Journal of Conservation Science
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• v.28 no.4
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• pp.329-341
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• 2012

Magai Wareiishi Jizo (Buddhist statue carved on rock surface) is close to shoreline and a part of rock block is periodically immersed by seawater. Rock material of the Wareiishi-jizo statue is composed mainly of medium or coarse-grained biotite granite and very durable. However, physical properties of the rock have been changed according to the complex interactions of the salt solution and surrounding environment. Exfoliation of the rock surface is a serious condition by salt crystallization. Exfoliation (14.6%) is concentrated on the upper part of the rock block with mainly boundary of seawater as the center. On the other hand, lower part of the rock block show black layers by contaminants deposition. In addition, brown discoloration and biological contaminants is overlapped. Rock surface show high discoloration rate of 50.5% (black discoloration, 29.2% > yellow discoloration, 14.1% > brown discoloration, 4.4% > green discoloration, 2.9%). Upper part of the rock block had a lot of change in the physical properties than lower part that is immersed by seawater. In particular, surface properties of the rock block was very weak state at the boundary surface of seawater permeation.

• Korean Journal of Heritage: History & Science
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• v.45 no.2
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• pp.100-113
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• 2012

The tombstone of Yi Chungmugong in the Joseon Dynasty located Namhae, Gyeongnam is consisted of sandstone. The Bisin and Bijwa of the tombstone have narrow range of magnetic value less than $0.2({\times}10^{-3}SI\;unit)$ and the Isu covered pigment on surface also has same magnetic susceptibility range. Therefore, the composition of all tombstone have similar lithological characteristics. The side of the tombstone appeared fine-grained sandstone to coarse-grained graywacke boundary clearly and back of tombstone observed lamination. Especially deterioration type is concentrated in front and back of the tombstone blistering (8.2% of back), scaling (10.2% of back), granular disintegration (28.1% of back) and discoloration (53.5% of front). Results of contaminants analysis, the front of the Bisin separated in 3 type of surface - granular disintegration-scaling. Among this area, surface detected Ca, S and Cl in high density, but these contaminants elements have more lower detect density from surface to granular disintegration. By contrast, on scaling area, these components are almost not detected, but Fe, K consisted of rock forming elements are detected. It is necessary to conservation and treatment of Yi Chungmugong tombstone in continuously, and salt cleaning on surface also needed. So through activity of conservation and restoration, epigraph preserved for their worth.

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