A comparison of the specific surface area of fly ash measured by image analysis with conventional methods
A comparison of the specific surface area of fly ash measured by image analysis with conventional methods
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DOI：
10.1016/j.conbuildmat.2018.09.131
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发表时间：
2018-11
影响因子：
7.4
通讯作者：
Tiao Wang;T. Ishida;R. Gu
中科院分区：
文献类型：
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作者：
Tiao Wang;T. Ishida;R. Gu
粉煤灰的比表面积（SSA）对其火山灰反应性和粉煤灰掺合混凝土的性能有重要影响。由于飞灰中含有大量不规则形状的颗粒和未燃烧的碳，用传统的分析方法来确定精确的SSA是很麻烦的。本研究对测定粉煤灰SSA的各种方法进行了评价和比较，包括Blaine透气性测试、氮吸收测试、激光衍射测试和图像分析。实验结果表明，Blaine空气渗透性测试和激光衍射测试由于涉及到完美的球形颗粒几何假设，往往低估了粉煤灰的SSA。通过氮吸收测试确定的SSA与未燃烧碳引起的显著高估有关。结合疯牛病的图像分析似乎给出了一致的结果，似乎是确定绝对SSA准确值的最有希望的方法。
The specific surface area (SSA) of fly ash has a significant effect on its pozzolanic reactivity and on the performance of fly ash-blended concrete. Because fly ash contains a considerable amount of irregularly shaped particles and unburned carbon, determination of an accurate SSA is analytically troublesome by conventional methods. Various methods for determining the SSA of fly ash are evaluated and compared in this study, including Blaine air permeability, nitrogen absorption testing, laser diffraction testing and image analysis. The experimental results show that Blaine air permeability and laser diffraction testing tend to underestimate the SSA of fly ash because they involve the assumption of perfectly spherical particle geometry. The SSA determined by nitrogen absorption testing is found to be associated with a significant overestimation induced by unburned carbon. Image analysis coupled with BSE appears to give consistent results and appears to be the most promising method of determining an accurate value for absolute SSA.