Abstract It is well understood that the partial replacement of portland cement with pozzolans in sufficient proportions results in improved long-term performance of concrete. However, dwindling availability of the most widely used pozzolan in the construction industry, fly ash, is forecast due to the termination of coal-fired electricity power stations around the world, necessitating the exploration of alternative pozzolans. Experimental investigations are conducted to study the performance of traditional pozzolans such as fly ash, silica fume and natural pozzolans (metakaolin, pumice, perlite and lassenite) together with novel pozzolans, including ground glasses (high-alkali and low-alkali), and ground bottom ash. Twenty-one concrete mixtures are examined for compressive strength, electrical conductivity, electrical resistivity, chloride permeability, and chloride migration coefficient. The reactivity of pozzolans studied is also determined in terms of compressive strength in lime-pozzolan mortar using a modified lime-reactivity test method. Many of the materials tested demonstrate the potential to be used in place of fly ash. However, a wide variation in the performance of these materials is evident which highlights the need for a reliable test to determine the level of reactivity of a pozzolan. The results indicate that the 7-day strength in the modified lime-reactivity test provides a good indication of the pozzolanic reactivity of the material and of how the material can be expected to contribute to the strength and permeability of concrete. The use of electrical resistivity as an indicator of the performance of pozzolans in terms of strength development and chloride penetration resistance when used to partially replace portland cement in concrete is also discussed.

中文翻译：

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天然火山灰、磨碎玻璃和煤底灰的火山灰反应性及其对混凝土氯化物渗透性的影响

摘要 众所周知，用足够比例的火山灰部分替代硅酸盐水泥可以提高混凝土的长期性能。然而，由于世界各地燃煤发电站的终止，预计建筑行业中使用最广泛的火山灰粉煤灰的可用性将减少，因此需要探索替代火山灰。进行了实验研究，以研究传统火山灰，如粉煤灰、硅粉和天然火山灰（偏高岭土、浮石、珍珠岩和亚长石）与新型火山灰，包括磨砂玻璃（高碱和低碱）和磨砂的性能。底灰。检查了 21 种混凝土混合物的抗压强度、电导率、电阻率、氯离子渗透率和氯离子迁移系数。所研究的火山灰的反应性也使用改进的石灰反应性测试方法根据石灰-火山灰砂浆的抗压强度来确定。许多测试的材料证明了替代粉煤灰的潜力。然而，这些材料的性能明显存在很大差异，这突出表明需要进行可靠的测试来确定火山灰的反应性水平。结果表明，改性石灰反应性测试中的 7 天强度很好地表明了材料的火山灰反应性以及材料如何对混凝土的强度和渗透性做出贡献。