中文摘要：

采用CT、X射线衍射、扫描电子显微镜等测试方法,通过对不掺矿物掺合料以及掺30%粉煤灰或50%矿渣的水泥净浆、水泥砂浆在室温下5%Na2SO4溶液中浸泡2a后的宏观破坏形态和浆体组分及浆体形貌的分析,从微观层次上研究了矿物掺合料对水泥基材料抗硫酸盐侵蚀破坏的影响。结果表明：侵蚀后不掺矿物掺合料的试件由表及里呈现三层不同侵蚀状态,即表层石膏区、中层钙矾石区以及内层未侵蚀区。矿物掺合料的C3A含量稀释效应、火山灰反应以及微集料填充效应协同作用的结果使得试件的抗硫酸钠溶液侵蚀破坏性能显著提高。但矿渣中活性Al3＋含量较高,能与SO42–反应生成大量钙矾石晶体,掺量不当会对试件的抗硫酸钠侵蚀性能不利。砂集料有阻碍微裂纹发展及增大试样内部不均匀性的相反作用,集料的含量、颗粒尺寸及分布对水泥基材料的抗硫酸钠侵蚀破坏性能的影响是以后研究中需关注的问题。

英文摘要：

The appearance observation, mineral composition, as well ;as microstructure morphology towards various cement pastes and motars with and without 30% fly ash or 50% slag dipped in 5% Na2SO4 solution at room temperature for 2 years were characterized by X-CT, X-ray diffraction and scanning electron microscopy to investigate the effects of mineral admixtures such as slag and fly ash on the sulfate resistance performance of cement-based materials from the micro-level angle. The results show that the specimens without mineral admixtures appear three different attack states from surface to inside, i.e., the gypsum area, the ettringite area and the unaffected area. Mineral admixtures can improve the sulfate resistance performance of cement-based materials via synergy effect of reducing C3A content, pozzolanic reaction and micro-aggregates filling. However, the improper content of slag in cement-based mate- rials has a negative effect on the sulfate resistance performance as active A13＋ reacts with SO4^2-to form massive ettringite. The sand aggregates can hinder the development of micro-cracks and increase the internal heterogeneity of the specimens. It is revealed that the content, particle size and distribution of aggregate all have effects on the sulfate resistant performance of cement-based materials, which should be a further research aspect.