Abstract Exposure of concrete to the atmosphere changes the microstructure of the cement paste. However, knowledge about the alteration of the porosity due to drying is typically not considered in deterioration processes of the hardened cement paste. The purpose of this article is to emphasize the importance of the porosity changes due to drying. 1 mm thick discs specimens made with four different pastes including three blended cements were exposed to CO2-free atmosphere at 70% relative humidity. The consequences of drying during one year of exposure were studied using XRD, and SEM for the phase assemblage, while porosity alteration was examined by MIP and high-resolution microscope. This study showed that the significant coarsening of the pores occurs during exposure at 70% RH which should be taken account of in durability studies.

中文翻译：

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环境干燥过程中水泥浆体微观结构变化的演变

摘要 混凝土暴露在大气中会改变水泥浆体的微观结构。然而，在硬化水泥浆的劣化过程中通常不考虑由于干燥而改变孔隙率的知识。本文的目的是强调干燥引起的孔隙率变化的重要性。用四种不同的糊状物（包括三种混合水泥）制成的 1 毫米厚圆盘试样暴露在相对湿度为 70% 的无二氧化碳环境中。使用 XRD 和 SEM 研究相组合在一年暴露期间干燥的后果，同时通过 MIP 和高分辨率显微镜检查孔隙率变化。该研究表明，在 70% RH 下暴露期间会发生显着的孔隙粗化，这在耐久性研究中应予以考虑。