波特兰-白云石水泥抗碳硫硅钙石型硫酸盐侵蚀（TSA）性能与机理研究

针对含白云石微粉水泥安全应用需求，基于白云石微粉在水泥中反应的“利弊双关”效应，项目提出“强化内源镁组分反应和功能性产物形成”以提高含白云石微粉水泥抗低温碳硫硅钙石型硫酸盐侵蚀（TSA）性能新思路。围绕“水泥中白云石微粉镁质组分在低温硫酸盐侵蚀条件下的演变及其与铝质组分的耦合机制”这一关键科学问题，研究白云石微粉掺量、细度、侵蚀温度、侵蚀介质及其与水泥C3A、铝质SCMs复合等手段对水泥抗TSA性能的影响规律；采用电子显微分析、X射线衍射、热分析、红外和拉曼光谱分析等先进材料表征技术，研究白云石反应程度、产物组成和微观结构演变规律；以期阐明白云石微粉与铝质组分的耦合机制，提出强化水滑石、碳铝酸钙等功能性产物的诱导形成和调控技术措施。项目开展对丰富水泥基材料TSA机理以及含白云石微粉水泥的安全应用具有重要理论和实际意义。

For the requirement of safety application of dolomite-bearing cement, a new technical approach is proposed for the improvement of the resistance to the thaumasite form of sulfate attack of dolomite-bearing cement based on the duplex effect of dolomite powder reactions in cement. The central thought for the realization of the new approach is to strengthen the reaction of the internal source of magnesium and the formation of functional products in the system. In order to elucidate the key scientific problem of the project, the evolution of magnesium in the dolomite powder reaction, and its coupling mechanism with aluminum-bearing constituents, the following subjects of the dolomite-bearing cement will be studied. Firstly, the effects of the following parameters, the fineness and dosage of dolomite powders, curing temperatures, the type reaction solutions, as well as their combination with C3A and aluminum-bearing SCMs on the TSA performance of cement will be examined. Then the evolution of the reaction degree of dolomite, the composition and microstructure of hydrates will be examined by advanced characterization techniques, such as electron microscopy, X-ray diffraction, thermal analysis, Infrared and Raman spectrum, etc. The coupling reaction mechanism of dolomite powder and aluminum-bearing constituents will be clarified, and the controlling technique for strengthening the formation of functional products, such as hydrotalcite and carboaluminates, will be proposed. It is significant for the project both in science and technology， i.e. to broaden the mechanism of TSA and to provide the technical approach for the safety application of dolomite-bearing cement.