Finely ground hardened cement pastes (hcp) under 75 μm were carbonated at varying relative humidities (23–95 % RH) to determine the carbonation rate that minimized CO₂ diffusion in the bulk paste. The amounts of portlandite (CH) and calcium carbonate (CC) polymorphs were quantified, and the decalcification and decomposition of C-A-S-H were analyzed using TGA, XRD, mass balance calculation, FTIR, and ²⁹Si MAS NMR spectroscopy. A higher RH accelerated the reaction rate, and CH dissolution stopped midway at 58 % RH or below because of the loss of connectivity with the pore solution in the CC shell around CH. The precipitated CC phase included calcite at high RH, whereas all three polymorphs formed at 58 % or lower RH; amorphous CC were detected at low RH. The decalcification and decomposition of C-A-S-H were observed at 45 % or higher RH; it was rarely carbonated at 33 % or lower RH.

75 μm 以下的精细研磨硬化水泥浆体 (hcp) 在不同的相对湿度 (23–95% RH) 下进行碳化，以确定最大限度减少 CO ₂ 在散装浆体中扩散的碳化速率。对氢钙石 (CH) 和碳酸钙 (CC) 多晶型物的量进行定量，并使用 TGA、XRD、质量平衡计算、FTIR 和 ²⁹ Si MAS NMR 光谱分析 C-A-S-H 的脱钙和分解情况。较高的相对湿度加速了反应速率，并且由于与 CH 周围的 CC 壳中的孔隙溶液的连通性丧失，CH 溶解在 58% RH 或更低的情况下中途停止。在高相对湿度下，沉淀的 CC 相包含方解石，而所有三种多晶型物均在 58% 或更低的相对湿度下形成；在低相对湿度下检测到无定形 CC。在45%或更高RH下观察到C-A-S-H的脱钙和分解；在 33% 或更低的相对湿度下很少发生碳酸化。