中国建材科学院 硕士论文
硅酸盐水泥与铝酸钙水泥复合性能和水化机理的研究

摘要
本文着重研究了不同比例的硅酸盐水泥与铝酸钙水泥复合体系的物理性能，运用XRD, DSC-TG, SEM以及ESEM等测试手段对其水化机理进行了初步探讨。此外还研究了在复合体系中加入石膏与石灰后，不同组份对复合体系的凝结时间、力学性能、干燥收缩以及水泥水化等方面的影响。
试验结果表明，硅酸盐水泥与铝酸钙水泥混合后，将对凝结时间产生显著的影响并导致力学及干缩性能的改变。铝酸钙水泥中掺入硅酸盐水泥，随着掺量的增加在一定的范围内出现缓凝现象;硅酸盐水泥中掺入铝酸钙水泥随着掺量的增加在一定范围内促凝，甚至达到快凝的程度。对于铝酸钙水泥而言，当硅酸盐水泥掺入量较小时抗压强度稍有提高，未发现有强度倒缩现象;对硅酸盐水泥来说，当铝酸钙水泥掺加量小于一定值，对强度的不利影响可以控制在较小范围内，尚未发现有强度倒缩现象。复合体系的胀后干缩有增大的趋势。
复合体系中熟石灰的加入，在一定范围内可以对提高早期强度起到一定的作用，还可以起到促凝作用并能减小干缩;复合体系中掺入生石灰，可以改善体系的中后期强度，对体系有促凝作用，并能改善收缩;在硅酸盐水泥与铝酸钙水泥复合体系中加入硬石膏，在一定的范围内可以提高复合水泥的早期强度和长期强度，在复合体系中加入硬石膏趋向于缩短体系的凝结时间，在一定范围内能改善收缩，但量过多会产生有害膨胀;复合体系中加入二水石膏，在一定的范围内可以提高复合水泥的早期强度和长期强度，在复合体系中加入二水石膏趋向于延长体系的凝结时间，同硬石膏一样，在一定范围内能改善收缩，但量过多会产生有害膨胀。
在复合体系中同时加入二水石膏和熟石灰，若配比适当，可以大幅度提高早期和后期强度，并使凝结时间有所缩短，使复合体系的干缩低于所用硅酸盐水泥干缩值，没有发现强度倒缩。
关键词:铝酸钙水泥硅酸盐水泥复合物理性能水化机理


Abstract
This paper stresses the investigation in the physical performances of a series of
composite cement systems composed of Calcium aluminate cement and Portland
cement in different proportions. XRD, DSC-TG, SEM and ESEM are used to determine hydrated products of composite cement systems, through which hydration mechanism is preliminary discussed. Furthermore, lime and gypsum are added to composite cement systems and the influence of them on the setting time, mechanical properties, dry shrinkage and hydration of composite cement systems is studied.
The test results reveal that blends of calcium aluminate cement and Portland cement exhibit different setting behavior, strength development and dry shrinkage
characteristics with that of each of two binders. Portland cement in some range added to calcium aluminate cement can retard the setting of the cement, and only in minor amounts of Portland cement slightly increase the compressive strength without losing strength afterwards. While some dose of Calcium aluminate cement blended to Portland cement can accelerate setting of the system, even cause the composite cement to instant setting. In minor amounts of calcium aluminate cement, unfavorable influence on strength is limited without losing strength over period of time. The dry shrinkage of Portland cement and calcium aluminate cement composite cement system trends towards enlarger.
Adding hydrated lime to the Calcium aluminate cement and Portland cement composite cement system, improve the early strength, accelerate setting and reduce dry shrinkage to some extent. Unslaked lime improves the long-term strength, accelerates setting and reduces dry shrinkage of the composite cement limitedly.Anhydrite will raise the early and long-teen strength, accelerate setting and reducedry shrinkage of the system, but if excessive amount of it will product disadvantageous expansion. De场drate gypsum will raise the early and long-term strength of the system, reduce dry shrinkage, and if excessive amount of it will product disadvantageous expansion either, but will prolong the setting time.
Adding both hydrated lime and dehydrate gypsum to the composite cement
system can improve the early and long-term strength largely, shorten the setting time, and make the dry shrinkage of the four contents is smaller than that of Portland cement, and doesn't cause the strength of the composite decrease with time increase.
Key words: Calcium aluminate cement; Portland cement; composite; erformance;
hydration mechanism

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