Abstract In the present work, a new experimental setup is designed and validated to characterize the CO2-binding capacity of cementitious materials based on their instantaneous rate of CO2 uptake. An experimental investigation is carried out on synthetized anhydrous (C3S, C2S, C3A) and hydrates (CH, C-S-H, AFt) exposed to ambient CO2 concentration at three different relative humidity (RH) levels. The BET surface area and the density are determined before and after exposure to natural carbonation. Results show that the CO2– binding capacity and rate increases highly with the RH. The instantaneous binding rate of the materials ranges from 10−6 to 5.10−10 gco2.gpowder−1.s−1. The highest degree of carbonation is found for ettringite powder (DoC = 45%). C2S and C3A are only slightly carbonated (DoC = 3%), while significant carbonation of C3S is observed only at 93% RH (DoC = 14%). A good (R2 = 0.94) agreement between the results determined using the new test method and thermogravimetric analysis (TGA) is noticed.

中文翻译：

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合成无水物和水合物的 CO2 结合能力：基于瞬时反应速率的测试方法验证

摘要 在目前的工作中，设计并验证了一种新的实验装置，以根据其瞬时 CO2 吸收率来表征胶结材料的 CO2 结合能力。对在三种不同相对湿度 (RH) 水平下暴露于环境 CO2 浓度的合成无水物（C3S、C2S、C3A）和水合物（CH、CSH、AFt）进行了实验研究。BET 表面积和密度在暴露于自然碳酸化之前和之后确定。结果表明 CO2 结合能力和速率随着 RH 的增加而显着增加。材料的瞬时结合率范围从 10-6 到 5.10-10 gco2.gpowder-1.s-1。钙矾石粉末的碳酸化程度最高 (DoC = 45%)。C2S 和 C3A 只是轻微碳酸化（DoC = 3%），而仅在 93% RH (DoC = 14%) 下观察到 C3S 的显着碳化。注意到使用新测试方法和热重分析 (TGA) 确定的结果之间具有良好的 (R2 = 0.94) 一致性。