DOI: 10.1016/j.jcou.2018.03.007
Scopus记录号: 2-s2.0-85043574447
论文题名: Carbon dioxide as an admixture for better performance of OPC-based concrete
作者: Qian X. ; Wang J. ; Fang Y. ; Wang L.
刊名: Journal of CO2 Utilization
ISSN: 22129820
出版年: 2018
卷: 25 起始页码: 31
结束页码: 38
语种: 英语
英文关键词: Calcium carbonate
; Carbon dioxide
; Hydration of cement
; Hydration products
; Ordinary Portland cement
Scopus关键词: Calcite
; Calcium
; Calcium carbonate
; Carbonation
; Cements
; Compressive strength
; Concrete mixing
; Concretes
; Hydration
; Mortar
; Portland cement
; Thermogravimetric analysis
; X ray diffraction
; Accelerated carbonation
; Beneficial utilizations
; Cementitious materials
; Fresh concrete mixes
; Heterogenous nucleation
; Hydration of cements
; Hydration products
; Ordinary Portland cement
; Carbon dioxide
英文摘要: This study explores a novel beneficial utilization of CO2 in ordinary Portland cement (OPC) based concrete. In existing studies, CO2 is mainly added into concrete through accelerated carbonation of fresh or hardened concrete, which is limited by the low diffusion of CO2 into the concrete. In addition, a high CO2 concentrated environment is needed to carbonate the concrete, making the existing methods only applicable to pre-cast concrete. Aiming to eliminate these limitations in the existing methods, this study proposes to directly add gaseous CO2 into fresh concrete mix as an admixture through a two-step mixing approach, pre-carbonation method. In this method, CO2 is first absorbed into a slurry of calcium-rich cementitious material in the first step, and then blended with the rest ingredients to produce concrete in the second step. This method can in-situ produce nano to sub-micro CaCO3 particles in fresh concrete, providing extra heterogenous nucleation sites for the hydration of OPC. Therefore, the hydration of OPC can be greatly improved, as evidenced by the calorimetry testing result. The addition of CO2 also produces more ettringite in the produced mortar, as revealed by X-Ray Diffraction and Thermogravimetric analysis. As a result, the overall volume of the hydration products of the OPC is increased, leading to denser microstructure of the mortar samples. For these reasons, the compressive strength of the cement mortar samples can be significantly improved by the proposed method. © 2018 Elsevier Ltd. All rights reserved. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/111898
Appears in Collections: 气候减缓与适应
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作者单位: Department of Civil, Construction and Environmental Engineering, University of Alabama, Tuscaloosa, AL 35487, United States; School of Civil Engineering and Architecture, Anhui University of Science and Technology, Huainan, Anhui 232001, China
Recommended Citation:
Qian X.,Wang J.,Fang Y.,et al. Carbon dioxide as an admixture for better performance of OPC-based concrete[J]. Journal of CO2 Utilization,2018-01-01,25