While early-age carbonation of concrete has gained interest as an avenue for carbon sequestration, the influence of curing age on carbon uptake for blended cements is an open subject. This has significant practical utility given the popularity of supplementary cementitious materials (SCM) as alternate binders. Pastes and mortar samples were prepared by replacing 20% by wt. cement with four SCMs of distinct composition (fly-ash, silica fume, calcined clay, ground-granulated blast furnace slag) and quartz. The effect of sample age on its carbon storing ability was examined by carbon curing at fresh state (0–24 h' age) and hardened state (24–48 h’ age). Carbon curing was done in a chamber using 99% purity CO₂ at 1.5 bars for 24 h. Thermo-gravimetric analysis showed that hardened-state curing stores up to 1.5 times more carbon than fresh-state curing. CH carbonation favors higher carbon storage than AFt/C–S–H phases. Hardened state curing reduces the bound water noticeably, but no major changes are observed in fresh state cured samples. Mercury intrusion porosimetry (MIP) revealed microstructure densification in hardened state cured samples (up to 18% reduction in pore volume) due to carbon curing, but no definite pattern is observed in fresh state curing. While no change in early-age strength is observed in hardened state curing, evident improvement is observed for fresh-state cured samples (7–37%). The findings of this study indicate that irrespective of the SCM, carbon curing at hardened state is more effective in storing carbon without degrading the later age strength of the mix.

虽然混凝土的早期碳化作为碳封存的途径引起了人们的兴趣，但养护年龄对混合水泥碳吸收的影响是一个开放的主题。鉴于辅助胶凝材料(SCM) 作为替代粘合剂的普及，这具有重要的实用价值通过替换 20%（重量）制备糊剂和砂浆样品。水泥具有四种不同成分的 SCM（粉煤灰、硅灰、煅烧粘土、磨碎的高炉矿渣）和石英。通过新鲜状态（0-24 小时）和硬化状态（24-48 小时）的碳固化来检查样品年龄对其碳储存能力的影响。碳固化在使用 99% 纯度 CO₂在 1.5 巴下 24 小时。热重分析表明，硬化状态固化的碳储存量是新鲜状态固化的 1.5 倍。与 AFt/C-S-H 相相比，CH 碳化有利于更高的碳储存。硬化状态固化显着降低了结合水，但在新鲜状态固化样品中没有观察到重大变化。压汞法(MIP) 显示由于碳固化，硬化状态固化样品中的微观结构致密化（孔体积减少高达 18%），但在新鲜状态固化中没有观察到明确的模式。虽然在硬化状态固化中未观察到早期强度的变化，但在新鲜状态固化样品中观察到明显改善（7-37%）。这项研究的结果表明，无论 SCM 是什么，硬化状态下的碳固化在储存碳方面更有效，而不会降低混合物的后期老化强度。