【作者】 陈烨；

【导师】 方永浩；

【作者基本信息】 河海大学 ， 材料学， 2007， 硕士

【摘要】 随着高性能混凝土技术的广泛应用，优质矿物掺合料的使用已不仅仅是有利于解决环保和节能问题，它已经成为对混凝土改性的一种重要组分。为改善混凝土的结构与性能，在混凝土中常采用不同活性的矿物掺合料复掺技术。本文主要以矿渣粉和粉煤灰为研究对象，在不使用外加剂和特殊工艺的情况下，等量取代相应比例的水泥熟料，其中矿物掺合料总掺量固定为50％和70％，研究复掺矿渣粉—粉煤灰复合胶凝材料及其混凝土的力学和耐久性等各方面的性能。通过一系列的试验研究，其试验结果表明矿渣粉、粉煤灰的掺入可以满足胶凝材料及混凝土的基本物理力学性能，并改善了耐久性。单纯复掺矿渣粉和粉煤灰矿物掺合料会大幅度降低胶凝材料的早期强度，且降低幅度随粉煤灰／矿渣粉比值的增大而略有增大，但对胶砂后期强度影响较小，且后期强度增长率快。复掺矿渣粉和粉煤灰的同时添加适量含硫酸盐工业废渣可一定程度提高胶凝材料的早期强度。同时矿渣粉和粉煤灰的掺入改善了胶凝材料的干缩性及耐蚀性能。与普通水泥混凝土相比，矿渣粉—粉煤灰复合混凝土在抗氯离子渗透方面具有较大的优势，但在抗碳化及抗冻方面有所欠缺。本文通过SEM、XRD、MIP等现代物相检测手段，研究复掺矿渣粉和粉煤灰对混凝土的改性机理，揭示微观结构与宏观性能间的内在联系。结果表明矿渣粉和粉煤灰的掺入改变了水化过程，使得水化产物及孔结构发生了变化，其中Ca（OH）₂的含量明显减少，大孔减少，孔结构得到了改善，孔分布更为合理，使得浆体更为密实，从而提高了复合胶凝材料及混凝土的抗硫酸盐、抗氯离子渗透等性能。更多还原

【Abstract】 With the development of high performance concrete technology, using high-quality mineral admixture is not only advantageous to solving the problem of environmental protection and energy conservation. Moreover, it has been a kind of important component in modifying the concrete. In order to improve structure and function of concrete, there is often use the technique which put various different active mineral admixtures in concrete. In this paper, slag and fly ash were taken as the research subjects. The influence of blast furnace slag powder-fly ash composite mineral admixture on the performance of ordinary Portland （OPC）cement were studied as cement is replaced by 50%～70% slag powder and fly ash without admixture and specious technology.Researching the basic physical, mechanical properties and durability index of cements, it proved that adding blast furnace slag and fly ash can not only satisfy the basic physical and mechanical properties, but also improve the durability of concrete. The results show that substituting 50%～70% OPC with the composite mineral admixture will greatly decrease the early age strength, while the late age strength of the cementing material will be little affected. Adding sulfate containing industrial waste will greatly increase the early age strength, with little influence on late age strength. By adding blast furnace slag and fly ash, the shrinkage and corrosion resistance of the cementitious materials can be improved. Slag-fly ash composite cement is similar to ordinary cement concrete in fundamental performance, but dominates on chloride ion erosion, falls short on carbonization performance and the frost resistance.The hydration products and paste structure of complex binders composed of Portland cement and blast furnace slag-fly ash mineral admixture were investigated with the aid of modern analysis method such as SEM, XRD and MIP. The results demonstrate that synthetic effects of powder slag and fly ash can improve the reaction of lava ash, and decrease the Ca （OH）₂ . The pore structure and distribution become better. Paste makes denser, thereby increasing the sulfate resistance and chloride ion erosion of composite cementitious material and concrete.更多还原