There are many precious historical monuments in Korea. Kyoungju City, the capital of the ancient Korea in A.D. 4–6th century is such an example. This study mainly focuses on the weathering problems of the historical monuments in Kyoungju City. Main weathering agent in this area has been known as salt crystallization due to its close location to the sea. Main source of salts can be either sea spray in coastal area or deicing salt in urban area. The ways that salts influence on stone are volume expansion in crystallization, volume expansion in hydration, difference in thermal expansion with minerals, osmotic pressure, etc. The physical properties of stone changes according to weathering. The change of tensile strength induced by salt crystallization test was clearly observed in this study. The decreasing trends of tensile strength according to weathering were different in each sample. This study showed the effects of salt crystallization on tensile strength of stone and salts from sea spray on the physical properties of stone located in coastal areas. Loosening of mineral grains due to salt crystallization was identified by SEM (Scanning Electron Microscopy) study.
There are many precious historical monuments in Korea. Kyoungju City, the capital of the ancient Korea in A.D. 4–6th century is such an example. Many of these historical monuments were made of stone. Stone has been used as building material of historical monuments, since the appearance and the characteristic of stone is very unique. Especially granite has been most frequently used. Understanding the characteristic of stone is important for conservation. Weathering is one of the most important characteristics of stone. As a result of weathering, the color of stone is changed or the physical property values are changed. This study mainly focuses on the weathering problems of the historical monuments in Kyoungju City.