The gamma polymorph of dicalcium silicate (γ-C₂S) is a potential low-carbon binder owing to its relatively high reactivity with carbon dioxide. This study invstigates the effect of barium (Ba) as a typical impurity on the carbonation characteristics of γ-C₂S. Results on the calcined γ-C₂S powders indicate that Ba doping has little effect on the crystal form of γ-C₂S, but substantially alters its morphology that is characterized by the increasing presence of wrinkles on the surface. Heat evolution during carbonation of the compacted γ-C₂S mortar mixtures shows the suppression of maximum temperature and the delay in reaching the peak in the very early age. This may be associated with the hindering of calcium dissociation as a result of the barium presence. The measured degree of carbonation and compressive strength development of the mortar samples are lower in the early stage but exceed the control in the later stage with a higher barium hydroxide (BH) doping amount. This can be attributed to the reduced thickness of moisture film coating the γ-C₂S particles. This retards the initial carbonation reaction, which may be beneficial for the penetration of CO₂ into the sample interior, thus promoting the universal degree of carbonation in the long term. Analysis on the carbonation products reveals aragonite is the preferable metastable calcium carbonate at a low BH doping amount while vaterite is exclusively found as the metastable phase at a high BH amount.

硅酸二钙的伽马多晶型物（γ-C ₂ S）是一种潜在的低碳由于其对二氧化碳有相对高的反应性粘合剂。本研究invstigates钡（Ba）的作为γ-C的碳酸化特性的典型杂质的影响₂在煅烧γ-C S.结果₂小号粉末指示的Ba掺杂有γ-C的晶型的影响不大₂ S，但实质上改变了其形态，其特征是表面上皱纹的存在增加。所述压实的碳酸化过程中放热γ-C ₂S砂浆混合物显示出最高温度受到抑制，并在很早的年龄就达到了峰值。这可能与由于钡的存在而阻碍钙解离有关。砂浆样品的碳化程度和抗压强度的发展程度在早期阶段较低，但在后期阶段则以较高的氢氧化钡（BH）掺杂量超过了对照。这可以归因于水分膜涂覆γ-C的厚度减小₂小号颗粒。这延迟了最初的碳酸化反应，这可能有利于CO ₂的渗透进入样品内部，从长远来看将促进普遍的碳酸化程度。对碳酸化产物的分析表明，文石是低BH掺杂量时较好的亚稳碳酸钙，而球v石是高BH量时唯一的亚稳相。