• Journal of Conservation Science
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• v.25 no.4
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• pp.431-438
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• 2009

We have investigated the suitable measuring method and condition on the hardness testing for the earthenwares excavated from Poongnap mud castle in Hanseong Baekje period. The earthenwares which used on hardness testing have been classified according to Mohs hardness and external form and color. The Ultrasonic and Equotip testing method have used to the hardness testing on the surface of the earthenwares and the Rockwell and Micro-vickers testing methods have used to the hardness testing on the cross section of the earthenwares. As the results, the two methods applied to the surface of the earthenwares were very hard on the precise measurement and the measuring values were incompatible with the tendency classified according to Mohs hardness and external form and color. On the testing for the cross section of earthenware, the Rockwell-superficial hardness testing method was more suitable for the soft texture earthenware and highest reproducibility of the measuring value obtained at the test load and indentor are 15kgf and 1/16 “iron ball, respectively. The Micro-Vickers hardness testing method was suitable for the hard texture earthenware and highest reproducibility and accuracy of the measuring value obtained at the test load is 100gf. This results show strong possibility of progress on the classifying and comparing study for hardness of the earthenware and therefore active studies are expected on the field.

• Journal of Conservation Science
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• v.26 no.3
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• pp.325-334
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• 2010

In order to clarify the effect of consolidant, the artificial porous material with low intensity was manufactured using granite powder and Portland cement. We have prepared four kinds of alkoxysilane system consolidants, a acrylic resin and a epoxy resin and investigated about characteristics before and after consolidation. As a result of the research, Silres BS OH 100 was effective for density and surface hardness. SS-101 with hydrophobicity and Site SX-RO with hydrophilicity had the good durability over salts weathering. On the other hand, Syton HT-50 and Paraloid B72 were easily destructed by salt weathering because they were concentrated on surface area by the low penetration depth. Araldite 2020 was the most effective consolidant for improvement of physical properties.

• Korean Journal of Heritage: History & Science
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• v.44 no.3
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• pp.78-91
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• 2011

The Usuki Stone Buddha Statues in Japan are carved on mainly dark gray welded lapilli tuff accompanied by lenticular fiamme. This rock is composed of matrix which contains feldspar and opaque minerals with some phenocrysts of quartz and feldspar. The matrix is slight to highly welded. The statues have been weathered and weakened by salt and freezing of water. To enhance the mechanical properties of the rock, consolidants and water repellents were applied. The absorption ratio of the rock was highly decreased after the treatment of the water repellents, the consolidant OH 100, as well. Ultrasonic velocity revealed similarly higher values in the treated rock by KSE 300 and OH 100, compared to non-treated rock. KSE 300, especially, highly increased the Equotip surface hardness. All studied consolidants and water repellents were found to change the original color of the stone. SNL, specifically, resulted the significant change in color. In addition, KSE 300 were observed to improve resistance to weathering such as microcrack and fracture through freezing-thawing test after treatment.