Anti-erosion Properties Of Low-quality Fly Ash Activation Of The Large Amount Of Low-quality Fly Ash Concrete

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.