臺灣古蹟、歷史建築修復現場花崗岩非破壞性調查法之研究—以礦物性質評估機械性質

A Non-Destructive Investigation Method of Granite in Taiwan’s Cultural Heritage Sites: The Study on the Correlation between Mineral Property and Mechanical Property

花崗岩是臺灣古蹟、歷史建築中相當重要的建材之一，可當結構材也可當裝飾材，且運用的範圍相當廣泛。而建材的基本性質則是建築體維護與修復時所需之必備資料，一直以來臺灣對於文化資產中的花崗岩本身並沒有系統性的研究。從外觀即可知道，花崗岩因為組成礦物比例的不同，產生相當多元的變化，而本文的目的即為深入分析不同組成礦物比例花崗岩石材性質之差異。透過抗壓強度、破壞模數、腳踏磨損抗力等試驗建立花崗岩機械性質數據，並透過全岩主量分析與礦物主量分析計算出花崗岩主要礦物成分比例，進而探討花崗岩機械性質與礦物比例之相關性。根據數據分析結果顯示，花崗岩組成礦物比例與抗壓強度、腳踏磨損抗力具高度相關性。最後藉由多變量線性迴歸法求得機械性質與礦物比例的經驗關係式。依此關係式，只要得知花崗岩中的礦物比例，即可推算出該花崗岩的機械性質與物理性質。此非破壞性調查方法既可節省機械性質實驗材料的大量消耗，又可利用較便利的方式取得石材維護所需之資訊，並且解決文化資產現場無法採樣的問題，將有利於古蹟、歷史建築中花崗岩之維護與修復。將此關係式及非破壞性調查法實際應用於文化資產案例，可看出石英與鹼性長石的含量比例對花崗岩的機械性質有關鍵性影響，且此法不僅可用來評估原有花崗岩的石材性質，也可應用於替壞修復材料的選用依據，有別於舊有調查方法，此法具有相當高的的便利性及有效性。

 

Granite is one of the most important building materials in Taiwan. It can be used as a structural material or a decorative material, and a widely used in traditional cultural heritage architecture. The basic property of building materials is necessary for maintenance and repair of buildings, but there is no systematically studied on granite in historic buildings in Taiwan. It can be seen from the appearance that granite has quite a variety of changes due to the different proportions of constituent minerals, and the purpose of this article is to deeply analyze the differences in the properties of granite materials with different proportions of minerals. The mechanical properties of granite are established through the compressive strength, modulus of rupture and wear resistance test, and the most accurate method for calculating the main mineral proportions of granite is based on calculating the correlations between major whole-rock compositions and major mineral compositions. Then discussing the correlation between the granite mechanical properties and mineral ratio. The results show that the main mineral proportions of granite has a high correlation with compressive strength and wear resistance, but has no obvious correlation with the modulus of rupture. Finally, to obtain the empirical formula between mechanical properties and the proportion of the mineral by the multivariate linear regression method. According to this formula, as long as the proportion of minerals in the granite is known, the mechanical and physical properties of the granite can be calculated. This non-destructive investigation method not only can reduce the large consumption of experimental materials of mechanical properties, but also use more convenient ways to obtain the required information for stone maintenance, which will be beneficial to the maintenance and repair of granites in historic buildings.