This study aims to understand the effect of the natural and accelerated carbonation on the alkali-activated slag (AAS) activated by sodium carbonate. Carbonation increased AAS paste total porosity but reduced slag containing materials (CEM III) porosity. The pH after carbonation was higher in AAS than in CEM III, which was explained by the buffering effect of the alkalis and the carbonation of the hydrotalcite. A higher CO percentage promoted the precipitation of nahcolite (NaHCO) rather than natron (NaCO) in AAS, which caused a decrease in the pH after carbonation in accelerated conditions. The decrease in the pH in accelerated conditions could also be due to a more advanced carbonation than in natural conditions.

中文翻译：

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自然和加速碳化对碳酸钠碱激活渣微观结构和pH值的影响

本研究旨在了解自然和加速碳化对碳酸钠活化的碱活化渣（AAS）的影响。碳化增加了 AAS 浆体的总孔隙率，但降低了含渣材料 (CEM III) 的孔隙率。 AAS 中碳酸化后的 pH 值高于 CEM III，这是由于碱的缓冲作用和水滑石的碳酸化作用造成的。较高的 CO 百分比促进了苏打石 (NaHCO) 而非泡碱 (NaCO) 在 AAS 中的沉淀，这导致加速条件下碳酸化后 pH 值下降。加速条件下 pH 值的降低也可能是由于比自然条件下更先进的碳酸化作用。