纳米SiO2和纳米Fe2O3掺量对混凝土性能的影响  

Effects of Dosage of Nano-SiO2 and Nano-Fe2O3 on the Performance of Concrete

作　　者：邢蓉[1] XING Rong(Shanxi Traffic Vocational and Technical College,Taiyuan 030031,China)

机构地区：[1]山西交通职业技术学院

出　　处：《人民黄河》2020年第1期131-134,144,共5页Yellow River

基　　金：国家自然科学基金资助项目(51308371)

摘　　要：研究了纳米SiO2和纳米Fe2O3掺量对混凝土坍落度、力学性能、抗盐冻性能以及抗渗性能的影响,并进一步采用扫描电镜-能谱仪(SEM-EDS)分析了纳米改性混凝土在浓度为3%的NaCl溶液中冻融循环试验前后微观形貌和元素组成的差异。结果表明:在低掺量下,掺入纳米材料对混凝土的和易性无显著不利影响,且当掺量为1.2%时,纳米改性混凝土的各项性能最优。掺加纳米SiO2和纳米Fe2O3均能促进水泥浆体的水化深度,改善混凝土密实性,并形成一定的粗糙结构从而阻止微裂纹扩展,提高混凝土的抗压和抗折强度,降低电通量和冻融质量损失率,增大混凝土相对动弹性模量。而同等掺量下,掺加纳米SiO2的效果比掺加纳米Fe2O3的效果好。The effects of nano⁃SiO2 and nano⁃Fe2O3 on a slump,mechanical properties,salt freezing resistance and permeability resistance of concrete were investigated.In addition,the microstructure and elemental composition of nano⁃modified concrete before and after freezing⁃tha⁃wing cycles in 3%NaCl solutions were characterized by scanning electron microscopy(SEM⁃EDS).The results indicate that there has no sig⁃nificant negative effect on the workability of concrete with low dosage nanoparticles.And when the content of nanoparticles is 1.2%,the com⁃prehensive performance of nano⁃modified concrete is optimal.The nano⁃SiO2 and nano⁃Fe2O3 not only promote the hydration depth of cement mortar but also improve the compactness of concrete and further form certain roughness structure to prevent micro⁃crack propagation.As a re⁃sult,the compressive strength,flexural strength and frost properties have been improved significantly.Furthermore,the performances of nano⁃SiO2 modified concrete are better than that of nano⁃Fe2O3 under the conditions of same dosage.

关 键 词：改性混凝土 纳米SIO2 纳米Fe2O3 力学性能 抗盐冻性能 微观形貌 

分 类 号：TU528[建筑科学—建筑技术科学]