Pinheiro Valber Domingos, Alexandre Jonas, Xavier Gustavo de Castro, Marvila Markssuel Teixeira, Monteiro Sergio Neves, de Azevedo Afonso Rangel Garcez
Laboratory of Advanced Materials, State University of the Northern Rio de Janeiro, Campos dos Goytacazes 28013-602, Brazil.
Civil Engineering Laboratory, State University of the Northern Rio de Janeiro, Campos dos Goytacazes 28013-602, Brazil.
Materials (Basel). 2023 Jul 2;16(13):4778. doi: 10.3390/ma16134778.
The search for alternative materials to replace ordinary Portland cement has been the object of work that enhances the investigation of the use of pozzolanic materials and the reduction of the carbon footprint with supplementary cementitious materials. However, not all materials are available to meet the large-scale demand for cement replacement. A relevant exception is the calcined clay, a material found worldwide that, when subjected to appropriate heat treatment, presents pozzolanic reactivity and can be used as a supplementary material to cement. This review presents, through a systematic search, methods for measuring the pozzolanic reactivity of calcined clays, namely, direct, indirect, qualitative, quantitative, chemical and physical methods such as electrical conductivity (Lùxan), the force activity index, the modified Chapelle, R, Frattini test, thermal analysis, X-ray diffraction and X-ray fluorescence spectrometry. The most usual methods to assess the pozzolanic reactivity of calcined clays were exposed and analyzed. It should be pointed out that there is greater use of the Frattini and modified Chapelle methods as well as the analysis of the mechanical strength behavior of the material in cementitious matrices. X-ray diffraction and thermal analysis were exposed as the most used correlation methods but it was also concluded that different tests are needed to generate accurate results.
寻找替代材料来取代普通硅酸盐水泥一直是相关研究工作的目标，这些研究工作加强了对火山灰质材料使用的调查，并通过补充胶凝材料来减少碳足迹。然而，并非所有材料都能满足大规模水泥替代的需求。一个相关的例外是煅烧黏土，这种材料在世界各地都有发现，经过适当的热处理后，具有火山灰反应活性，可作为水泥的补充材料。本综述通过系统检索，介绍了测量煅烧黏土火山灰反应活性的方法，即直接法、间接法、定性法、定量法、化学法和物理法，如电导率（卢桑法）、力活性指数、改良夏佩尔法、R法、弗拉蒂尼试验、热分析、X射线衍射和X射线荧光光谱法。文中阐述并分析了评估煅烧黏土火山灰反应活性最常用的方法。需要指出的是，弗拉蒂尼法和改良夏佩尔法以及对材料在胶凝基体中的力学强度行为分析的应用更为广泛。X射线衍射和热分析被认为是最常用的关联方法，但也得出结论，需要进行不同的测试才能得出准确结果。
