纳米SiO_2和CaCO_3对超高性能水泥基复合材料的影响  

Effects of nano-SiO_2 and nano-CaCO_3 on properties of ultra-high performance cementitious composites

作　　者：戎志丹[1] 姜广[1] 孙伟[1] 

机构地区：[1]东南大学江苏省土木工程材料重点实验室,南京211189

出　　处：《东南大学学报（自然科学版）》2015年第2期393-398,共6页Journal of Southeast University：Natural Science Edition

基　　金：国家自然科学基金资助项目(51308110);江苏省自然科学基金资助项目(BK2012754);高性能土木工程材料国家重点实验室开放基金资助项目(2012CEM007)

摘　　要：系统研究了双掺纳米SiO2和纳米CaCO3对超高性能水泥基复合材料力学性能的影响规律,采用水化热分析、XRD、MIP和纳米压痕等多种微观分析测试手段对其水化进程及微结构进行了研究.结果表明,双掺纳米材料可进一步提升材料的各项力学性能,纳米CaCO3的最佳掺量为3%-5%.纳米SiO2的高反应活性促进了早期水泥水化的进程,与水泥水化产物Ca（OH）2反应产生C-S-H凝胶,纳米CaCO3主要起到了填充增强和晶核的作用,二者共同作用下,使得复合材料结构更为密实,孔隙率进一步降低,孔径得到细化,超高密度C-S-H凝胶大量生成,界面区得以强化,异常均匀致密的微观结构使得复合材料在宏观上体现出优异的力学性能.The effects of nano-SiO2 and nano-CaCO3 on the mechanical performance of ultra high performance cementitious composite（ UHPCC） were studied. The hydration process and microstructure of UHPCC were investigated via hydration heat analysis method,XRD（ X-ray diffraction）,MIP（ mercury intrusion porosimetry）,nanoindentation and other analysis testing methods. The results indicate that the mechanical performance is improved by adding nano-SiO2 and nano-CaCO3. The optimal content of nano-CaCO3 is about 3% to 5%. With high chemical reactivity,nano-SiO2 promotes the early-age hydration process in cement,reacting with Ca（ OH）2to form C-S-H gel. The nano-CaCO3 phases may fill up void spaces and act as nucleation sites. As a result,the composites structure can be condensed significantly with the decrease of porosity and pore size. More hydrated products of UHPCC lead to formation of ultra high density（ UHD） C-S-H which strengthens the interface zones. The UHPCC has excellent mechanical performance due to its compact microstructure.

关 键 词：纳米SIO2 纳米CACO3 超高性能水泥基复合材料 微结构 纳米压痕 

分 类 号：TU528[建筑科学—建筑技术科学]