Department of Integrated Energy and Infra System, Kangwon National University, Chuncheon-Si, 24341, South Korea.
Yunnan Key Laboratory of Disaster Reduction in Civil Engineering, Faculty of Civil Engineering and Mechanics, Kunming University of Science and Technology, Kunming, 650500, China.
Environ Sci Pollut Res Int. 2023 Jul;30(32):78665-78679. doi: 10.1007/s11356-023-28072-0. Epub 2023 Jun 5.
Ultra-high-performance concrete (UHPC) exhibits high compressive strength and good durability. However, owing to the dense microstructure of UHPC, carbonation curing cannot be performed to capture and sequester carbon dioxide (CO). In this study, CO was added to UHPC indirectly. Gaseous CO was first converted into solid calcium carbonate (CaCO) using calcium hydroxide, and the converted CaCO was then added to UHPC at 2, 4, and 6 wt% based on the cementitious material. The performance and sustainability of UHPC with indirect CO addition were investigated through macroscopic and microscopic experiments. The experimental results showed that the method used did not negatively affect the performance of UHPC. Compared with the control group, the early strength, ultrasonic velocity, and resistivity of UHPC containing solid CO improved to varying degrees. Microscopic experiments, such as heat of hydration and thermogravimetric analysis (TGA), demonstrated that adding captured CO accelerated the hydration rate of the paste. Finally, the CO emissions were normalized according to the compressive strength and resistivity at 28 days. The results indicated that the CO emissions per unit compressive strength and unit resistivity of UHPC with CO were lower than those of the control group.
超高强度混凝土 (UHPC) 表现出高抗压强度和良好的耐久性。然而，由于 UHPC 的微观结构致密，无法进行碳化养护以捕获和隔离二氧化碳 (CO)。在本研究中，通过间接的方式向 UHPC 中添加 CO。首先，使用氢氧化钙将气态 CO 转化为固体碳酸钙 (CaCO)，然后将转化后的 CaCO 以 2、4 和 6 wt%的比例基于胶凝材料添加到 UHPC 中。通过宏观和微观实验研究了间接添加 CO 对 UHPC 的性能和可持续性的影响。实验结果表明，所采用的方法并未对 UHPC 的性能产生负面影响。与对照组相比，含有固体 CO 的 UHPC 的早期强度、超声波速度和电阻率都在不同程度上得到了提高。水化热和热重分析 (TGA) 等微观实验表明，添加捕获的 CO 加速了浆体的水化速率。最后，根据 28 天的抗压强度和电阻率对 CO 排放量进行了归一化。结果表明，CO 排放量与单位抗压强度和单位电阻率的比值均低于对照组。
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