This paper investigates the effects of metakaolin and pumice pozzolans as replacement cementitious materials with Portland cement in conventional concrete (NC) on compressive strength, permeability properties, chloride penetration resistance under immersion and tidal conditions, as well as chemical resistance to simulated acid rain attacks in concrete. A control mixture along with two mixtures with 15% replacement of pumice and metakaolin with Portland cement was used. The results showed that the concrete containing metakaolin and pumice had higher compressive strength at all ages than the control specimen. Also, it had a significant effect on chloride penetration resistance enhancement in both immersion and tidal conditions compared to the control specimen. The use of metakaolin and pumice as a 15% alternative to cement could not compensate for the lack of the aluminate phase in the cement matrix; the alkalinity of the pore solution in the mixture reduced, resulting in lower chloride content. The scanning electron microscope results showed that replacing pumice with cement reduces the Ca/Si ratio; however, metakaolin showed more CSH stages, which increases the Ca/Si ratio. Also, the SEM images of mixtures containing pumice and metakaolin revealed that pumice and metakaolin powder enhanced the CSH phase in the entire structure of the concrete. However, in acidic conditions, the Ca/Si ratio reduced significantly, diminishing performance under acidic conditions.

本文研究了偏高岭土和浮石火山灰作为常规混凝土（NC）中波特兰水泥的替代胶凝材料对沉浸和潮汐条件下抗压强度，渗透性，抗氯化物渗透性以及对模拟酸雨侵蚀的耐化学性的影响。具体的。使用了对照混合物以及两种混合物，其中用硅酸盐水泥替代了15％的浮石和偏高岭土。结果表明，含有偏高岭土和浮石的混凝土在各个年龄段的抗压强度均高于对照标本。而且，与对照样品相比，它在浸入和潮汐条件下均对提高氯化物渗透阻力具有显着影响。偏高岭土和浮石作为水泥的15％替代品不能弥补水泥基体中铝酸盐相的缺乏。混合物中孔隙溶液的碱度降低，导致氯化物含量降低。扫描电子显微镜结果表明，用水泥代替浮石可降低Ca / Si比。然而，偏高岭土显示出更多的CSH阶段，从而增加了Ca / Si比。另外，含浮石和偏高岭土的混合物的SEM图像显示，浮石和偏高岭土粉末增强了混凝土整个结构中的CSH相。但是，在酸性条件下，Ca / Si比显着降低，从而降低了在酸性条件下的性能。导致较低的氯化物含量。扫描电子显微镜结果表明，用水泥代替浮石可降低Ca / Si比。然而，偏高岭土显示出更多的CSH阶段，从而增加了Ca / Si比。另外，含浮石和偏高岭土的混合物的SEM图像显示，浮石和偏高岭土粉末增强了混凝土整个结构中的CSH相。但是，在酸性条件下，Ca / Si比显着降低，从而降低了在酸性条件下的性能。导致较低的氯化物含量。扫描电子显微镜结果表明，用水泥代替浮石可降低Ca / Si比。然而，偏高岭土显示出更多的CSH阶段，从而增加了Ca / Si比。另外，含浮石和偏高岭土的混合物的SEM图像显示，浮石和偏高岭土粉末增强了混凝土整个结构中的CSH相。但是，在酸性条件下，Ca / Si比显着降低，从而降低了在酸性条件下的性能。含浮石和偏高岭土的混合物的SEM图像显示，浮石和偏高岭土粉末增强了混凝土整个结构中的CSH相。但是，在酸性条件下，Ca / Si比显着降低，从而降低了在酸性条件下的性能。含浮石和偏高岭土的混合物的SEM图像显示，浮石和偏高岭土粉末增强了混凝土整个结构中的CSH相。但是，在酸性条件下，Ca / Si比显着降低，从而降低了在酸性条件下的性能。