This paper investigated the influence of different CO₂ concentrations on the microstructural and mechanical development of reactive MgO cement (RMC) concrete. Combination of various analyses revealed the enhancement of hydrated magnesium carbonate (HMC) phases with relatively superior micro-mechanical properties as the CO₂ concentration increased from ambient (~0.04%) to accelerated (5–20%) levels. The higher CO₂ diffusion within samples cured under 5–20% CO₂ increased the compressive strength by ~5 times. While samples cured under 20% CO₂ revealed high early strengths, the formation of a dense HMC layer on the sample exterior led to limitations on further CO₂ diffusion. Use of 5% CO₂ produced comparable strengths as 20% CO₂ at 28 days, highlighting the potential of using lower concentrations. Samples cured under 10% CO₂ revealed the best performance at 28 days, thereby defining this environment as the most favorable condition for the development of microstructural and mechanical properties of RMC concrete.

本文研究了不同浓度的CO ₂对活性MgO水泥（RMC）混凝土微观结构和力学性能的影响。各种分析的结合表明，随着CO ₂浓度从环境水平（〜0.04％）增加到加速水平（5-20​​％），水合碳酸镁（HMC）相的增强具有相对优越的微机械性能。在5-20％CO ₂下固化的样品中较高的CO ₂扩散使抗压强度提高了约5倍。虽然在20％CO ₂下固化的样品显示出较高的早期强度，但在样品外部形成致密的HMC层导致进一步限制CO _{2的使用。}扩散。在28天时使用5％CO ₂产生的强度与20％CO ₂相当，这凸显了使用较低浓度的潜力。在10％CO ₂下固化的样品在28天时表现出最佳性能，从而将这种环境定义为RMC混凝土微观结构和力学性能发展的最有利条件。