Characterization of carbonation behavior of fly ash blended cement materials by the electrochemical impedance spectroscopy method

详细信息    查看全文

• 作者：Biqin Dong ; Qiwen Qiu ; Zhentao Gu ; Jiaqi Xiang ; Canjie Huang ; Yuan Fang ; Feng Xing ; Wei Liu ; ^{Liuwei@szu.edu.cn" class="auth_mail" title="E-mail the corresponding author}
• 关键词：Fly ash blended cement materials ; Pozzolanic reaction ; Carbonation ; Electrochemical impedance spectroscopy ; Equivalent circuit model ; Prediction
• 刊名：Cement and Concrete Composites
• 出版年：2016
• 出版时间：January 2016
• 年：2016
• 卷：65
• 期：Complete
• 页码：118-127
• 全文大小：1936 K

文摘

The carbonation behavior of fly ash blended cement materials is studied by the electrochemical impedance spectroscopy (EIS) method, and a novel equivalent circuit model R_s(Q₁(R_ct1W₁)) (Q₂(R_ct2W₂)) is proposed to investigate the influence of fly ash on the carbonation process in the cementitious materials. The experimental results demonstrate that the diameter of the impedance arc in high frequency region increases as carbonation progresses. Increasing the amount of fly ash incorporated in the cement paste is also found to enlarge the high frequency arc. The carbonation process can be quantified by the parameter R_ct2 extracted from the equivalent circuit model R_s(Q₁(R_ct1W₁)) (Q₂(R_ct2W₂)). It is found that the R_ct2 value increases with increase in fly ash content. A linear relationship between the R_ct2 value and the carbonation time is also observed. As a consequence, prediction of the carbonation depth of fly ash bended cement materials can be achieved through knowledge of the R_ct2 value.