大掺量低质粉煤灰混凝土抗侵蚀性能研究及低质粉煤灰活化初探

【作者】 刘振清；

【导师】 蒋林华；

【作者基本信息】 河海大学 ， 材料学， 2001， 硕士

【摘要】 本文较系统深入地研究大掺量低质粉煤灰混凝土抗侵蚀性能。混凝土抗侵蚀性能与其中的水泥水化、水化产物组成与数量、混凝土的微观结构以及所处环境有关。混凝土胶凝材料中的水泥遇水即发生水化，随着水化龄期的延长生成大量的Ca（OH）₂，这是造成混凝土抗侵蚀性能降低的重要原因。在混凝土中掺入大量的粉煤灰，并且合理地设计粉煤灰混凝土的配合比可以大大改善其抗侵蚀性能。 论文首先采用CTS25型非金属超声波检测仪，对在不同养护制度与养护龄期（包括标准养护和侵蚀溶液中浸泡）情况下的各相应龄期混凝土进行无损检测。接着，测试了混凝土宏观力学强度，同时对混凝土超声波传播速度检测值和抗压强度测试值进行回归分析，给出它们之间的关系方程式。 然后利用热分析技术（DTA）、扫描电子显微镜（SEM）等现代测试技术与分析方法，对不同配合比的粉煤灰混凝土的水化进程、水化产物组成与数量的变化（包括标准养护和受溶液侵蚀两种情况）及其形貌进行系统的研究。并对大掺量粉煤灰混凝土抗侵蚀性能增强机理进行分析与探讨。 此外，论文还对低质粉煤灰活化技术进行初步的探索与研究。测定了由两种Ⅲ级粉煤灰配制的高掺量粉煤灰水泥浆体在不同的激发剂种类与掺量情况下各相应龄期的抗折、抗压强度，并对其中几种粉煤灰水泥浆体各相应龄期的pH值进行测试，对粉煤灰活化机理和影响粉煤灰“增钙”的因素进行分析与探讨。更多还原

【Abstract】 The corrosion resistance of Large-Volume low-quality Fly Ash Concrete (LVFAC) is studied systematically and deeply in this thesis. The corrosion resistance of concrete is associated with its hydration of cement, the components and quantities of hydration products, its micro-structure and its lying environment. The cement exposed to water hydrates immediately in the cementitious materials of concrete, and produces Ca(OH)2 with the prolonging of hydration time, which is the important cause to reduction of corrosion resistance of concrete. When concrete is mixed with large-volume fly ash, and its mix proportions are designed rationally, the corrosion resistance of fly ash concrete can be greatly improved.The concrete to different curing time, which are lain in the circumstances of different curing system and curing time, has been tested non-destuctively firstly by CTS25 ultrasonic apparatus for material testing. Subsequently, the macro-strengths of mechanics of concrete are examined. At the same time, the relationship between the sound speed traveling through the concrete and the compressive strength of concrete are analyzed, and then* relationship equations are obtained.And then the hydration process, the components and quantities of hydration products and its morphology of fly ash concrete of each mix proportion are systematically investigated by DTA and SEM. The enhancing mechanism of the corrosion resistance of LVFAC is analyzed and discussed.Moreover, the activated technologies of low-quality fly ash are preliminary explored and studied. The strengths of high volume fly ash mortars of different curing time, which are mixed with two kinds of low-quality fly ash, and different kinds and quantities of activators, are examined. And the PH values of their fly ash mortars are examined. The activation mechanism of fly ash and the factors influencing "enhancing-calcium" are analyzed and discussed.更多还原