Study of Frost Weathering Mechanism of Porous Materials and its Protective Measures.

1)寒冷地区的砖砌建筑和石碑因冰冻融化循环而变质。对北海道旭川县的砖烟囱和福岛县的YNaizu的砖烟囱的冻害进行了实地调查，结果表明，供水是造成冻害的重要因素。发展了计算砖砌建筑和石质古迹中水分分布和水流的数值方法，该方法也适用于干旱地区砖质古迹中与盐风化有关的水分和溶质运移的计算。2)冻胀现象是冻害的基本机制。在多孔材料的冻结过程中，水被诱导流动到冻结前沿，并以透镜的形式分离。为了阐明冻胀机理，对不同直径的玻璃微珠在不同温度条件下进行了冻胀试验。实验结果给出了…实验结果与基于晶体生长理论的冻胀模型进行了比较。这些结果发表在国际研讨会上并发表在期刊上。3)石质纪念碑的多孔材料，如奥雅凝灰岩，在冻胀压力超过其抗拉强度时会破裂。利用显微镜和录像系统对不同温度条件下冰的离析过程进行了室内实验研究。提出了该过程的冻胀模型，并与实验结果进行了比较。计算结果与实验结果吻合较好。这些结果发表在国际研讨会上。4)大分县石碑的盐风化现象被观察到。盐风化是由地表蒸发过程中靠近地表的盐类结晶过程引起的。这一物理过程类似于霜冻风化，物质的运移用相似的微分方程式来表示。由于这些相似之处，我想把我关于霜冻风化的研究主题扩大到可以在亚洲国家的历史遗迹中看到的盐风化。较少

1) The brick buildings and stone monuments in cold regions deteriorate due to freezing and melting cycles. The field survey on the frost damages of brick chimney of Asahikawa Kaiko-sha in Hokkaido Prefecture and brick chimney of Ynaizu in Fukushima Prefecture revealed that the water supply was important factor for frost damage. The numerical technique to calculate water content distribution and water flow in brick buildings and stone monuments was developed, This technique is also applicable to the calculation of the water and solute transport related to salt weathering in the brick monuments in dry regions.2) The basic mechanism of frost weathering is frost heave phenomenon. During the freezing of porous material, water is induced to flow to the freezing front and segregates as lenses. In order to clarify the frost heave mechanism, frost heaving experiments were performed using glass beads of different diameter under different temperature conditions. The experimental results gave the … More relationship between the ice segregation rates and temperature conditions, The experimental results were compared with the frost heave model based on the crystal growth theory. These results were reported in the International Symposium and published in journals.3) The porous materials of stone monuments , such as Oya tuff break when the frost heave pressure exceeds their tensile strength. The laboratory experiments were carried out to investigate the ice segregation process under the different temperature conditions by using microscope and video recorder system. The frost heave model for this process was proposed and compared with the experimental results. The calculated results corresponded well with the experimental results. These results were presented at the International Symposium.4) The salt weathering is observed for stone monuments in Oita Prefecture. The salt weathering is caused by the salt crystallization process near the surface during the water evaporates from the surface. This physical process is similar to the frost weathering, The material transport is expressed by similar differential equations. Because of these similarities, I would like to widen my study topic related to frost weathering to salt weathering which can be seen in historical sites in Asian countries. Less