Abstract The development and improvement of brick materials is still based on empirical knowledge and large testing series. To enable a physically based optimization in terms of thermal and mechanical properties of clay bricks, detailed knowledge of their microstructure is required. We here present comprehensive investigations on the pore space of bricks made of five different clayey raw materials used in European brick production. Application and combination of micro-computed tomography and scanning electron microscopy delivered precise pore size distributions based on the real pore diameter and unaffected by the pore throat. The former also enabled to resolve the 3D pore structure down to a pore diameter of approximately 5.5 micrometers and gave access to porosity distributions over the sample's thickness. Furthermore, the brick's true densities were determined applying the Archimedes' principle and verified by helium pycnometry measurements. The extensive database generated in this work and the linking of results from different methods allow for new insights and a better understanding of these often used brick materials.

中文翻译：

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欧洲砖工业中使用的由五种粘土原料制成的烧制砖的孔隙空间的多技术定量表征

摘要 砖材的开发和改进仍以经验知识和大系列试验为基础。为了在粘土砖的热性能和机械性能方面实现基于物理的优化，需要详细了解其微观结构。我们在此对欧洲砖生产中使用的五种不同粘土原料制成的砖的孔隙空间进行了全面调查。显微计算机断层扫描和扫描电子显微镜的应用和组合提供了基于真实孔径且不受孔喉影响的精确孔径分布。前者还能够将 3D 孔隙结构解析到大约 5.5 微米的孔径，并提供样品厚度范围内的孔隙率分布。此外，砖' s 的真实密度是应用阿基米德原理确定的，并通过氦比重测量法进行验证。在这项工作中生成的广泛数据库以及来自不同方法的结果的链接允许对这些经常使用的砖材料有新的见解和更好的理解。