Considering the range of P_CO2 of previous laboratory experimental works, in this study the carbonation rate of class G Portland cement was investigated at room temperature, in the P_CO2 interval from 1 to 51 bar, to fill the existing gap of knowledge, through three types of laboratory experiments. Cement hydration (accompanied by limited carbonation) was carried out for 28 days at atmospheric conditions. Cement carbonation was then investigated using a micro-reactor by reacting, in distinct runs, cement powder samples, under stirred conditions, and massive samples, under stagnant conditions, with pure CO₂(g) and MilliQ water. After the completion of each experiment, chemical analyses on both the aqueous solution (IC, ICP-OES, acidimetric titration) and the solids (XRD, SEM, TGA/DTA) were performed.

In type 1 experiments, cement powder was reacted at 11 bar P_CO2, for 1, 3, 6, 21, 67, 97 and 120 h. Portlandite was only present in the hydrated cement paste and was converted to CaCO₃ in less than 1 h. In type 2 experiments, cement powder was reacted for 6 h at P_CO2 of 1, 11, 31 and 51 bar. The extent of cement carbonation was similar for any P_CO2 values.

The experiments of type 3 were performed with cement cube samples at 11 bar P_CO2 for 6, 24 and 210 h. The average carbonation depth attained was 0.23 mm in 1 day, and resulted to be linearly related to the square root of reaction time indicating that cement carbonation rate was controlled by diffusion (Fickian behavior).

考虑到以往实验室实验工作的 P _CO2范围，本研究在室温下研究了 G 级硅酸盐水泥的碳化率，在 P _CO2区间为 1 到 51 bar，以填补现有知识空白，通过三个实验室实验的类型。水泥水化（伴随着有限的碳酸化）在大气条件下进行 28 天。然后使用微反应器通过在不同的运行中将水泥粉末样品（在搅拌条件下）和块状样品（在静止条件下）与纯 CO ₂反应来研究水泥碳酸化(g) 和 MilliQ 水。每个实验完成后，对水溶液（IC、ICP-OES、酸度滴定）和固体（XRD、SEM、TGA/DTA）进行化学分析。

在类型 1 实验中，水泥粉末在 11 bar P _CO2下反应1、3、6、21、67、97 和 120 小时。硅酸盐仅存在于水化水泥浆中，并在不到 1 小时内转化为 CaCO ₃。在类型 2 实验中，水泥粉末在 1、11、31和 51 巴的P _CO2下反应 6 小时。任何 P _CO2值的水泥碳化程度都相似。

类型 3 的实验使用水泥立方体样品在 11 bar P _{CO2 下}进行 6、24 和 210 小时。1 天内达到的平均碳化深度为 0.23 毫米，结果与反应时间的平方根线性相关，表明水泥碳化速率受扩散控制（菲克行为）。