当前位置: X-MOL 学术Cem. Concr. Res. › 论文详情
Our official English website, www.x-mol.net, welcomes your feedback! (Note: you will need to create a separate account there.)
NOx uptake capacities and sequestration pathways by hydrated cementitious phases
Cement and Concrete Research ( IF 10.9 ) Pub Date : 2022-06-15 , DOI: 10.1016/j.cemconres.2022.106882
Qingxu Jin , Samuel N. Lucas , Yuanzhi Tang , Kimberly E. Kurtis

This study seeks to quantify NOx sequestration by individual hydrated cementitious phases (C-S-H, AFm-SO4, and Ca (OH)2), establish a fundamental understanding of the reaction pathways, and reveal the effects of carbonation (CaCO3 and AFm-CO3). For uncarbonated phases, the highest NOx uptake was measured in C-S-H, with the produced nitrite/nitrate physically bound on solid surface. For AFm-SO4, an anion exchange process was observed, where nitrite/nitrate substitute for sulfate and form new AFm-NO2/NO3. Ca(OH)2 showed undetectable NOx uptake, which may be due to the relative low temperature and relative humidity. For carbonated phases, CaCO3 exhibited an improved NOx uptake compared to uncarbonated phases, with uptake capacity three times higher than that of C-S-H. The result of AFm-CO3 indicates that carbonation could potentially inhibit the anion exchange process that was observed in AFm-SO4. These findings provide guidelines for the rational design and optimization of cement-based materials for enhanced NOx sequestration.



中文翻译:

水合胶凝相的 NOx 吸收能力和封存途径

本研究旨在量化各个水合胶凝相(CSH、AFm-SO 4和 Ca (OH) 2 )对 NO x的封存,建立对反应途径的基本理解,并揭示碳化作用(CaCO 3和 AFm- CO 3 )。对于未碳酸化的相,在 CSH 中测量了最高的 NO x吸收,产生的亚硝酸盐/硝酸盐物理结合在固体表面上。对于AFm-SO 4,观察到阴离子交换过程,其中亚硝酸盐/硝酸盐取代硫酸盐并形成新的AFm-NO 2 /NO 3。Ca(OH) 2显示检测不到 NO x吸收,这可能是由于相对较低的温度和相对湿度。对于碳酸化相,与非碳酸化相相比,CaCO 3表现出改进的 NO x吸收,其吸收能力是 CSH 的三倍。AFm-CO 3的结果表明,碳酸化可能会抑制在 AFm-SO 4中观察到的阴离子交换过程。这些发现为合理设计和优化水泥基材料以增强 NOx 封存提供了指导

更新日期:2022-06-16
down
wechat
bug