Abstract The carbonation mechanisms of ground, hydrated cement pastes that mimic recycled concrete fines are investigated under direct wet carbonation. The carbonation is a sequential processes including dissolution of the hydrates, transport of the dissolved material to the precipitation sites and precipitation of the reaction products. During the first stages of carbonation, when portlandite reacts, the reaction is limited by the amount of dissolved CO2 and potentially by the calcite precipitation rate. When portlandite is depleted, the kinetics is dominated by the dissolution of other hydrates and diffusion of calcium into the solution. The main carbonation products are calcite and an alumina-silica (hydrate) gel. The hydrotalcite-like phase appears to be stable towards carbonation under the experimental conditions employed in this work. The CO2 concentration and the paste composition have a limited influence on the reaction mechanisms as well as on products formed.

中文翻译：

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水泥浆体强制碳化动力学

摘要 研究了在直接湿碳化下模拟再生混凝土细粉的研磨水化水泥浆体的碳化机制。碳酸化是一个连续的过程，包括水合物的溶解、溶解的物质运输到沉淀位点和反应产物的沉淀。在碳酸化的第一阶段，当波特兰石发生反应时，反应受到溶解的 CO2 量的限制，并可能受到方解石沉淀速率的限制。当硅酸盐耗尽时，动力学由其他水合物的溶解和钙向溶液中的扩散控制。主要的碳酸化产物是方解石和氧化铝-二氧化硅（水合物）凝胶。在这项工作中采用的实验条件下，类水滑石相似乎对碳酸化是稳定的。