土墼牆及編竹夾泥牆泥土材料組成之研究──以雲林及嘉義地區傳統建築為例

Study of the Earth Composition of Adobe Walls and Bamboo-Daub Walls—A Case Study of Traditional Buildings, Yunlin County and Chiayi County

泥土為臺灣傳統建築主要建材之一，常用於許多古蹟及歷史建築土墼牆、編竹夾泥牆上，但修復時常以不當之泥土種類或配比來取代原有材料，而造成古蹟及歷史建築原有風貌喪失，甚至降低了牆體耐震性能與耐候性能。為釐清傳統建築土墼牆體之土墼磚與粉刷泥漿、編竹夾泥牆體使用泥土材料之方式，本研究修正簡易土壤粒徑分析方法，針對雲林縣、嘉義縣一帶34棟傳統建築之土墼牆體、編竹夾泥牆體泥土材料進行成分分析，分析結果顯示調查案例土墼牆體及編竹夾泥牆體使用之泥土多為黏土、沉泥等細粒料土壤，與國外使用較多細砂有明顯差異，且不同種類牆體、不同部位之泥土配比及添加物並不相同，其中土墼磚所含之黏土比例明顯高於編竹夾泥牆之夾泥及土墼牆體表面粉刷泥漿，而粉刷泥漿、編竹夾泥牆體夾泥添加稻殼或稻桿之比例遠大於土墼磚。

In Taiwan, earth is a traditional building material, which is often applied to the adobe walls and bamboo-daub walls of cultural heritage buildings and monuments. In the past, when many adobe walls and bamboo-daub walls of cultural heritage buildings and monuments have been repaired, the ingredients of the earth using in restoration have never been clearly defined. Earth containing inappropriate compositions is still often used and this reduces the aseismic and weatherproof resistance capacity of the walls. In this research, the soil particle size distribution of the earth in adobe walls and bamboo-daub walls of 34 traditional buildings in Yunlin and Chiayi County were analyzed using the siphon test. The analytical results show that most of the earths used in traditional adobe walls are composed of clay-silt. The proportions of clay and silt in different types of walls is not identical. The earth of adobe walls contains more clay than bamboo-daub walls and the surface plaster of adobe walls. Furthermore, the ratio of added rice husk or rice stalk to the earth of the wall plaster and earth with bamboo-daub is much greater than that of the adobe brick.