Stone heritages, such as stone architectures, stone statues, graveposts and stone towers, are generally located outside and they are exposed to the wind and rain. Therefore, they have been defaced and collapsed due to weathering. The main reason of the weathering is the existence and movement of water in the rock heritages, and the appropriate protection method is expected in order to keep heritages in good conditions. Kyusyu Archaeological Laboratory introduced a new method, Aquo-Siloxane Method, in order to protect the stone heritages. In this method, the protection material is painted on the surface of heritages, and the material penetrates into the rock pores. Then the water in the stone structures is captured by the material and it becomes stable. However, the stability of the captured water has been not evaluated quantitatively yet, and the characteristics of Aquo-Siloxane Method also have not been verified yet. In this study, the tests related to the water migration in rock pores, such as water permeation tests, evaporation tests and capillary tests, were applied to the porous rock samples. By comparing the state between with and without protection, the effect of Aquo-Siloxane method was verified. It was found that the water migrations in the pores were restrained in the rock sample once the water was captured by the protection material. The condition when the protection material is painted was also confirmed, and it was found that the protection effect was not influenced by the initial water content of rock samples.

Various kinds of heritages, such as architectures, statues, grave posts and towers, are made by stone, and they are facing the crisis of weathering. Therefore, it is necessary to give appropriate treatments to keep them in good conditions. Kyushu Research Institute for Cultural Properties Inc. and Kumamoto University introduced a new method, Aquo-Siloxane Method, in order to protect the stone heritages. In this study, preservation effect by AquoSiloxane method towards water permeation and material diffusion was verified. Here one-dimensional permeation and diffusion tests were conducted, and the intrinsic permeability and diffusion coefficient of rock samples with and without Aquo-Siloxane treatments were evaluated. As rock samples, 3 types of sandstones and concrete were applied. It was found that the permeability decreased to less than 1/10 to 1/100 of without Aquo-Siloxane treatment, and that the effect gradually developed during more than one year. One-dimensional diffusion tests were also conducted, and the diffusion process in rock samples are visualized by X-ray CT scanner system. It was confirmed internal structures of samples are clearly visualized, and that the diffusion process was also visualized as X-ray CT images. In order to extract the necessary information due to diffusion, image subtraction method was applied to image data. Then, by comparing obtained CT image data and numerical solutions, diffusion coefficients of rock samples with and without Aquo-Siloxane treatments were evaluated. As a result, diffusion coefficients also became smaller by applying Aquo-Siloxane treatments. It is revealed that material movement due to diffusion was also efficiently suppressed by applying Aquo-Siloxane method. Finally, Aquo-Siloxane method was applied to a stone heritage. It was found that no more chippings and cracks were observed and that the heritage has been kept in good condition for at least four years.

have introduced a new method, the Aquo-Siloxane method, to protect stone heritage sites. The application procedure of the method is very simple and it has been applied to several stone heritage sites. Here, one-dimensional diffusion tests using potassium iodide solution were conducted on two types of porous rock samples, Berea sandstone and Kimachi sandstone. The Aquo-Siloxane treatment was applied to the rock samples, and its inhibitory effect on diffusion phenomena was verified. The characteristic point of this study was that the diffusion phenomena was visualized using a µ-focus X-ray computed tomography (CT) scanner, and the density distribution inside the rock sample was quantitatively evaluated. When the Aquo-Siloxane treatment was applied, it was found that density increment resulting from diffusion was suppressed by nearly 1/2 to 1/3 of that without treatment in both the rock samples. The number of applications of Aquo-Siloxane treatment was also verified. It was found that there were no significant differences in the number of treatments, and it was proved that one application was sufficient to suppress the migration of solute into the rock sample. [