Carbonation of low heat portland cement paste precured in water for different time

作     者：Deping Chen Etsuo Sakai Masaki Daimon Yoko Ohba 

作者机构：Civil and Environmental Engineering School University of Science and Technology Beijing Beijing 100083 China Graduate School of Science and Engineering Tokyo Institute of Technology Tokyo 152-8552 Japan 

出 版 物：《Journal of University of Science and Technology Beijing》 (北京科技大学学报（英文版）)

年 卷 期：2007年第14卷第2期

页      面：178-184页

核心收录：

学科分类：08[工学] 081304[工学-建筑技术科学] 0805[工学-材料科学与工程（可授工学、理学学位）] 080502[工学-材料学] 0813[工学-建筑学] 

基　　金：This study was financially supported by the Ministry of Education  Culture  Sports  Science  and Technology  Japan 

主　　题：carbonation carbon dioxide absorption vaterite BET surface area pore size distribution 

摘      要：The carbonation technique was applied to accelerate the hydration of low heat portland cement （LHC）. Before carbonation, the demoulded pastes were precured in water for 0, 2, 7, and 21 d, respectively. The results show that precuring time in water strongly influences the carbonation process. The phenolphthalein test indicates that the paste precured in water for a shorter time is more quickly carbonated than that for a longer time. The content of calcium hydroxide increases with increasing the precuring time in water, whereas, the amount of absorbed carbon dioxide changes contrarily. Scanning electron microscope （SEM） observation shows that portlandite always fills up big air bubbles in the paste during precuring in water, and the mercury intrusion porosimetry （MIP） results show that there are less large capillary pores in the paste precured in water for a longer time. It is found that the paste without precuring in water has more carbon dioxide absorption during curing in carbon dioxide atmosphere, and its total pore volume decreases remarkably with an increase in the carbonation time than that precured in water. X-ray diffraction （XRD） and Brunauer-Emmett-Teller （BET） surface area analyses indicate that the carbonate products are vaterite and calcite; CxSHy formed from carbonation has low BET surface area in comparison with that of C-S-H formed from curing in water.