【摘 要】
：
Due to the stringent requirements for the reduction of greenhouse gases emissions in the cement industry, the production of blended cements is rapidly increasing.The use of limestone as mineral additi
【机 构】
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R&D Cement Additives Division, Mapei SpA, Milan, Italy
【出 处】
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The 14th International Congress on the Chemistry of Cement (
论文部分内容阅读
Due to the stringent requirements for the reduction of greenhouse gases emissions in the cement industry, the production of blended cements is rapidly increasing.The use of limestone as mineral addition, established in some countries since many decades and recognized in technical standards, has only recently been subject of scientific attention.Wrongly considered as an inert filler, limestone can influence cement hydration leading to the formation of Aft and Afm phases based on carbonate ion.A thermodynamic approach allowed to study the equilibrium between carbonate, sulfate and aluminate phases and to predict the effect of limestone addition on cement performances.Considering that several chemical additives have a strong influence on aluminate hydration, it is expected that the aforementioned equilibrium is modified by their presence.In this paper the effect of some selected cement chemical additives (widely used in the formulations of grinding aids and performance enhancer) on the hydration and physicho-mechanical behavior of limestone blended cements is deeply investigated.Thanks to the combination of quantitative X-Ray diffraction and calorimetric techniques with the measurement of mortar properties, some hypothesis on the mechanism of action of cement additives are proposed.
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