ABSTRACT

The benefits of using earthen material such as cob in architecture are increasingly acknowledged, yet remaining concerns about safety prevent its broader use. This is particularly true in areas that experience earthquakes and heavy rain. To better understand the structural characteristics of cob in such harsh environmental conditions, this study examines cob structures found in rural areas of Japan, which are subject to those conditions. On average, we found they have been standing for 80 years. First, through interviews and surveys, this study verifies that amateurs built these structures; that is, they were built under worst-case scenarios for quality control. Second and mainly, field work measurements provide data to show deterioration patterns over decades, and sometimes centuries. Major findings were as follows. As expected, the bottom of the walls is most susceptible to deterioration. Unexpectedly, the data appears to show that deterioration is minimized when foundations are short, using small stones, 80 mm to 140 mm in height. The average deterioration at the bottom for walls with tall foundations (150 mm in height and over) is 64 mm, and for walls with a short foundation is 25 mm.

摘要

在建筑中使用土制材料（例如玉米芯）的好处越来越多，但对安全性的担忧仍然阻碍了其更广泛的使用。在经历地震和大雨的地区尤其如此。为了更好地了解在如此恶劣的环境条件下玉米芯的结构特征，本研究检查了在日本农村地区发现的玉米芯结构，这些结构受这些条件的影响。平均而言，我们发现它们已经站立了 80 年。首先，通过访谈和调查，本研究验证了这些结构是由业余爱好者建造的；也就是说，它们是在质量控制的最坏情况下构建的。其次，也是主要的，实地工作测量提供了显示几十年甚至几个世纪的恶化模式的数据。主要发现如下。正如预期的那样，墙的底部最容易变质。出乎意料的是，数据似乎表明，当地基较短时，使用高度为 80 毫米至 140 毫米的小石头，可以最大限度地减少劣化。基础高（150 毫米及以上）墙的底部平均劣化为 64 毫米，基础短的墙为 25 毫米。