Hydration evolution of pre-cast concrete with steam and water curing
来源期刊：中南大学学报(英文版)2013年第10期
论文作者：巴明芳 QIAN Chun-xiang(钱春香)
文章页码：2870 - 2878
Key words：microstructure evolution; hydration kinetics; effective curing condition; pre-cast concrete
Abstract: The hydration characteristics of pre-cast concrete considering the effects of effective initial steam-curing and water-curing duration were measured and analyzed with XRD, TG, X-ray CT, SEM-BSE and MIP techniques. The results show that the effective initial steam-curing duration for pre-cast concrete with lower water-binder ratio was 10-14 h at 50 °C and the initial water-curing duration was 7-14 d. And the hydration evolution of cement, fly ash and slag in pre-cast concrete was obtained respectively by combining the hydrochlorides and EDTA selecting dissolution methods, based on which the contents of hydrated and anhydrate in concrete were calculated and the corresponding dynamic capillary porosity was also determined. Moreover, the comparison between calculated results and experimental ones indicates that the proposed evolution models of microscopic characteristics corresponding to hydration kinetics of cemented materials could be adopted to predict the developing trend of capillary porosity and hydration-products content in pre-cast concrete with fly ash and slag under certain curing conditions.
BA Ming-fang(巴明芳)1, QIAN Chun-xiang(钱春香)2
(1. Faculty of Architectural Civil Engineering and Environment, Ningbo University, Ningbo 315211, China;
2. School of Materials Science and Engineering, Southeast University, Nanjing 211189, China)
Abstract:The hydration characteristics of pre-cast concrete considering the effects of effective initial steam-curing and water-curing duration were measured and analyzed with XRD, TG, X-ray CT, SEM-BSE and MIP techniques. The results show that the effective initial steam-curing duration for pre-cast concrete with lower water-binder ratio was 10-14 h at 50 °C and the initial water-curing duration was 7-14 d. And the hydration evolution of cement, fly ash and slag in pre-cast concrete was obtained respectively by combining the hydrochlorides and EDTA selecting dissolution methods, based on which the contents of hydrated and anhydrate in concrete were calculated and the corresponding dynamic capillary porosity was also determined. Moreover, the comparison between calculated results and experimental ones indicates that the proposed evolution models of microscopic characteristics corresponding to hydration kinetics of cemented materials could be adopted to predict the developing trend of capillary porosity and hydration-products content in pre-cast concrete with fly ash and slag under certain curing conditions.
Key words:microstructure evolution; hydration kinetics; effective curing condition; pre-cast concrete
