Study on deterioration and moisture properties of tuff stones used in a historical building

2023 Fiscal Year Final Research Report

• Project/Area Number: 20K04821
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 23020:Architectural environment and building equipment-related
• Research Institution: Mukogawa Women's University
• Principal Investigator: UNO Tomoko 武庫川女子大学, 建築学部, 准教授 (90415620)
• Co-Investigator(Kenkyū-buntansha): 伊庭 千恵美 京都大学, 工学研究科, 准教授 (10462342) ; 安福 勝 近畿大学, 建築学部, 教授 (20581739)
• Project Period (FY): 2020-04-01 – 2024-03-31
• Keywords: 石材 / 劣化 / 水分移動 / 材料物性 / 透水性 / 降雨 / 凍結 / 乾湿

Outline of Final Research Achievements

This study aimed to determine the causes and mechanisms of the varied deterioration observed in two types of materials applied on the exterior of a historical building, Koshien Hall. In this study, the extent of deterioration and the surrounding surface areas were investigated. The respective materials’ properties such as the thermal moisture of the stones were estimated, and the stones’ temperature and moisture levels were simulated by heat and moisture transfer analysis.
The results revealed the following: there is a big difference between the moisture transfer coefficients of the two stones when wet and dry; the area with high moisture content during rainfall differed; the time of rainfall, the amount of solar radiation after rainfall, and the amount of nocturnal radiation affect the freezing and drying that cause deterioration; and the difference in the extent of deterioration can be explained by the range of high moisture content.

Free Research Field

建築環境工学

Academic Significance and Societal Importance of the Research Achievements

本研究は、歴史的建造物「旧甲子園ホテル」をフィールドとした研究であり、その外装材に使われる凝灰岩の保存に注目している。同様の凝灰岩は多くの歴史的建造物や文化財にも使われている。ここで観察される劣化の性状を整理し、石材の基本的物性や熱水分特性との関係、劣化の要因とメカニズムが明らかになることで、石材特性や劣化の状況に応じた防水・排水、温度制御、日射・夜間放射の低減などの環境制御が可能となり、劣化予防の対策や維持管理の方法を提示することができる。また、一般に60年程度と考えられている建材用石材の寿命に対して、ここでの成果はオリジナル材料を永く活用するための基礎資料となりうる。