• Journal of Conservation Science
• /
• v.35 no.3
• /
• pp.259-268
• /
• 2019

Stone cultural heritage will either be damaged by composite damage or will lose its original historical authenticity starting with the moment it is created. Various artificial interventions to restore them to their original state have been described, centering on the conservation treatment case of the Stupa of State Preceptor Jigwang from the Wonju Beopcheonsa Temple Site. Restoration of the Jigwang stone pagoda was carried out after securing all scientific and technological means for the research and protection of the cultural heritage in question. Since its restoration was promoted to retain its aesthetic and historical value and was based on a careful understanding of the original materials and prototypes, extensive restoration was sought, which contributed to the restoration of the original form, resulting in both preservation and authenticity.

• Journal of Conservation Science
• /
• v.34 no.3
• /
• pp.211-225
• /
• 2018

The Stupa of the State Preceptor Jigwang from the Beopcheonsaji temple site in Wonju (National Treasure No. 101) was built in the Goryeo Period (around the 11th century), with very excellent style and techniques. It was returned to the Korea after being taken to Osaka of Japan without notice in 1912, and was severely damaged during the Korean War. Subsequently, the Stupa was restored using restoration materials like mortar, and relocated to the National Palace Museum of Korea. Surface contaminants in the Stupa primarily existed around the restoration materials. Black discoloration, which indicates a high discoloration grade, signified a high possession rate in the north and inner regions of the Stupa, which may be related to the relative moisture maintenance time. Most surface contaminants were calcite and gypsum; the black discoloration area underwent secondary discoloration due to air pollution. Moreover, the stone properties exhibited a relatively low discoloration grade, exhibiting crystallized contaminants that partly covered the rock-forming minerals. Overall, the Stupa deteriorated due to discoloration and being covered by lime materials, which were dissolved as the mortar degraded. Hence, it required contaminants removal, surface cleaning and desalination during conservation treatment, in order to control the rate of physicochemical deterioration by contaminants.

• Journal of Conservation Science
• /
• v.34 no.6
• /
• pp.503-515
• /
• 2018

Stupa of State Preceptor Jigwang at Beopcheonsa temple site, Wonju, was conserved and restored in 1957. It was necessary to assess the degree of damage to the used mortar and to provide objective data on the necessity of its removal. Therefore, the HCP(half-cell potential) measurement used in concrete fields was applied. Multi-regression analysis of HCP data, following the rapid corrosion test of the roofstone mortar used by the rebar, resulted in a high correlation of HCP values(0.86), depending on the amount of corrosion and cover depth used for the steel bar. As a result, high correlation values(0.86) for the coefficients of determination were derived. The showed that the measurement of the wet conditions -431 to -663 mV on the roofstone indicated a corrosion damage rate of 90% or more after removal and restoration.

• Journal of Conservation Science
• /
• v.37 no.5
• /
• pp.411-425
• /
• 2021

The Stupa of State Preceptor Jigwang from Beopcheonsa Temple Site in Wonju (National Treasure) is a representative stupa of the Goryeo Dynasty, with outstanding Buddhist carvings and splendid patterns, clearly indicating its honoree and year of construction. However, it was destroyed by bombing during the Korean War (1950-1953) and repaired and restored with cement and reinforcing bars in 1957. The surface condition of the original stone shows long-term deterioration due to the m ortar used in past restorations. In order to identify the exact causes of deterioration, the m ortar and surface contaminants on the original stone were analyzed. Portlandite, calcite, ettringite, and gypsum from the mortar were identified, and its ongoing deterioration was observed through pH measurements and the neutralization reaction test. Analysis of surface contaminants identified calcite and gypsum, both poorly water-soluble substances, and their growth in volume among rock-forming minerals was observed by microscopy. Based on those results, semi-quantitative analysis of Ca and S contents significantly influencing the formation of salt crystals was conducted using P-XRF to analyze the basis of surface deterioration, and cross-validation was performed by comparing the body stone affected by the mortar and the upper stylobate stone unaffected by the mortar. Results indicate that the elements are directly involved in the surface deterioration of the body stone.

• Korean Journal of Heritage: History & Science
• /
• v.53 no.4
• /
• pp.100-117
• /
• 2020

National Treasure no. 101, the stupa of State Preceptor Jigwang from the Beopcheonsa Temple Site in Wonju has been transferred from place to place and reassembled several times since it was built. In particular, overall dismantling and repair was carried out in 1957 to restore parts damaged by bombing during the Korean War. Documented information on the repair process and materials used at that time does not exist. However, various types of metal materials used for this stupa have been identified during conservation work. Besides clamps anchor bolts, 9mm-thick circular rebars were mainly used for joining the parts of this stupa, while circular rebars and wires of various thicknesses were used for joining the parts with mortar restoration materials. Although deformed bars are typically used for stone pagodas classified as architectural structures, smooth circular rebars were used in this case. In terms of restoration using mortar, material shapes were transformed, bound alternately, and twisted irregularly to improve bonding strength and coherence in order to insert restoration materials and to bolster structural weaknesses. In addition, metallographic analysis showed the material to be hypo-eutectoid steel with low carbon content. Many non-metallic inclusions in the shape of drops of different sizes were included, which do not affect the whole elemental composition due to the very small quantities involved. Qualitative and EPMA analysis of Mn and S, which were not identified by SEM-EDS area analysis, established an even distribution of MnS in crystal grains of the microstructure, regardless of the shape of the samples. It is presumed that secondary homogenization and softening might have been conducted after manufacturing to facilitate the working process. Furthermore, in consideration of properties indicating that the thinner the steel is, the less carbon content contained and the greater the elasticity and elongation, it is judged that restoration work was ordered.