纳米CaCO_3对超高性能混凝土性能影响的研究  

Influence of Nano-CaCO_3 on Ultra High Performance Concrete

作　　者：黄政宇[1] 祖天钰[1] 

机构地区：[1]湖南大学土木工程学院,长沙410082

出　　处：《硅酸盐通报》2013年第6期1103-1109,1125,共8页Bulletin of the Chinese Ceramic Society

基　　金：国家自然科学基金(51178711)

摘　　要：利用水化放热分析、差热分析、收缩仪、扫描电镜、流动扩展度、力学试验等手段研究了纳米CaCO3对超高性能混凝土体系的水化放热特点、结合水含量、收缩、水化产物特征、流动性、力学性能的影响;分析了胶凝材料体系水化硬化后的微观结构及其对宏观性能的影响规律。结果表明:超低水胶比的超高性能混凝土的水化放热速率低,但掺入纳米CaCO3能促进水化反应,提高水化开始时的放热速率。同时,掺入纳米CaCO3会使得超高性能混凝土的流动性下降,自收缩增加,但能提高超高性能混凝土的抗压强度及抗折强度,改善水泥浆体的微观结构,使得超高性能混凝土的结构更加均匀、密实。The hydration process such as bound water content,exothermic rate and autogenous shrinkage,characteristics of hydration products,spread value and mechanic performance of ultra high performance concrete（UHPC） which containing nano-CaCO3 particles were investigated using calorimetry,thermogravitymetric analysis,non-contact concrete shrinkage deformation tester,SEM,fluidity,mechanic tests.Microstructure of hardened cementitious system and its influence on macro performance were analyzed.The results indicate that the exothemic rate of UHPC is very low while it can increase the exothermic rate when adding nano-CaCO3 into the system.It will also decrease spread value,increase the amount of autogenous shrinkage,improve the flextural strength and compressive strength,and optimize the microstructures when containg nano-CaCO3 particles.

关 键 词：超高性能混凝土 纳米碳酸钙 水化 自收缩 微观结构 

分 类 号：TU528[建筑科学—建筑技术科学]