Accelerated carbonation presents a promising approach for enhancing the early strength of cement-based materials while simultaneously sequestering CO₂. This study examines the carbonation of γ-C₂S, β-C₂S, and C₃S compacts to identify the critical factors influencing strength development over extended curing periods. Analysis of the evolution of mechanical properties, microstructure, and phase assemblages reveals three key factors: 1) Degree of carbonation, which directly correlates with the density of the compacts; 2) Crystalline form and crystal size of calcium carbonate, influencing the strength of the crystal interface; and 3) Silica gels, which act as a phase boundary, with hydration products forming in the later stages of β-C₂S carbonation potentially affecting strength. The findings indicate that calcite promotes rapid strength gain in the early stages, while aragonite contributes to long-term performance. The presence of hydration products within the silica gel phase boundary may explain the observed strength reduction in β-C₂S compacts during extended carbonation. These insights provide valuable guidance for optimizing the design and application of carbonated cement-based materials for sustainable construction.

中文翻译：

---

阐明影响碳酸压块强度的因素：从 γ-C2S、β-C2S 和 C3S 的碳化中获得见解


加速碳化提供了一种很有前途的方法，可以提高水泥基材料的早期强度，同时封存 CO₂。本研究研究了 γ-C₂S、β-C₂S 和 C₃S 压块的碳化，以确定在延长固化期内影响强度发展的关键因素。对机械性能、微观结构和相组合演变的分析揭示了三个关键因素：1） 碳化程度，这与压块的密度直接相关;2） 碳酸钙的结晶形式和晶体大小，影响晶体界面的强度;3） 硅胶，充当相边界，在 β-C₂S 碳化的后期形成水合产物，可能会影响强度。研究结果表明，方解石在早期阶段促进强度的快速增加，而文石有助于长期性能。硅胶相边界内水合产物的存在可以解释在长时间碳化过程中观察到的 β-C₂S 压块强度降低的原因。这些见解为优化碳酸盐水泥基材料的设计和应用以实现可持续建筑提供了宝贵的指导。