氧化石墨烯对水泥水化历程的调控机理研究

项目名称： 氧化石墨烯对水泥水化历程的调控机理研究

项目编号： No.51508020

项目类型： 青年科学基金项目

立项/批准年度： 2016

项目学科： 建筑环境与结构工程学科

项目作者： 王琴

作者单位： 北京建筑大学

项目金额： 20万元

中文摘要： 氧化石墨烯由于其独特的二维纳米结构，能大幅度提高水泥基复合材料的韧性，促进水化历程，显著降低水化热，但是其水化机理尚不明确。本课题拟从氧化石墨烯的结构控制出发，研究氧化石墨烯表面化学和片层尺寸对水泥水化反应程度、水化热、水化速率、水化动力学的影响规律；通过原位测试技术，研究氧化石墨烯对水化初期塑性浆体表面形貌、絮凝结构和流变性能的影响规律，在此基础上，结合硬化水泥浆体微观结构的表征以及力学和收缩性能的评价，阐明氧化石墨烯在水化初期的物理化学反应，揭示水化机理，并基于氧化石墨烯调控晶体溶解、成核、长大和相分离的过程，建立水化模型，提出氧化石墨烯调控和优化水泥水化的方法和理论。上述工作的实现，将丰富水泥水化理论，为如何科学、高效地在水泥基复合材料中利用氧化石墨烯提供理论指导。

中文关键词： 氧化石墨烯；水泥基复合材料；水化机理；微观结构；宏观性能

英文摘要： As a graphene derivative, graphene oxide is mono-layer of sp2-hybridized carbon atoms with a mixture of carboxyl, hydroxyl and epoxy functionalities. Our recent study has shown that the addition of GO could improve the strength and toughness of cement-based composites, promote the hydration process and reduce the hydration heat. However, effect of GO on hydration mechanism has been rarely investigated. In this subject, the effects of the surface chemistry and graphite flake size of GO on the degree of hydration, hydration heat, hydration rate, hydration kinetics at different stages of hydration are investigated. In-situ testing technique is used to investigate the effects of GO on the surface morphology, flocculent structure and rheology of plastic cement paste at early stage of hydration. And the microstructure, mechanical strength and drying shrinkage of hardened cement paste are also investigated and correlated to the hydration behavior. In the basis of above-mentioned study, the role of the high specific surface energy and oxygen functional groups of GO in the physico-chemical interactions, nucleation and crystal growth, phase separation of the cement hydration products during hydration process at early stage is elucidated. The hydration mechanism is enclosed, the hydration model is established and the method and theory of modification mechanism of GO during the hydration process are proposed. This subject will contribute to the hydration theory of cement and the effective application of GO in the cement-based composites.

英文关键词： Graphene oxide;Cement-based composites;Hydration mechanism;Microstructure;Property