摘要
制备了纳米SiO2混凝土试件,测试质量损失率、相对弹性模量和有效孔隙率,根据冻融循环作用下混凝土的质量损失率、相对弹性模量和有效孔隙率随纳米SiO2掺量的变化规律,分析了抗冻耐久性指数与有效孔隙率之间的关系,研究了纳米SiO2混凝土的冻融损伤机理。研究结果表明:(1)纳米SiO2混凝土的质量损失率随冻融循环的增大而先减小后增大;(2)纳米SiO2混凝土的相对弹性模量随冻融循环的增大而减小;(3)掺加纳米SiO2可以有效提高混凝土的抗冻性能,最佳的纳米SiO2掺量为4%;(4)纳米SiO2混凝土的冻融损失机理为冻融循环引发混凝土内部孔隙结构破坏,进而造成混凝土力学性能下降。
The nano SiO2 concrete specimens were prepared to test the mass loss rate,relative elastic modulus and effective porosity.According to the variation of concrete mass loss rate,the relative elastic elastic modulus and the effective porosity of the concrete under the action of freeze-thaw cycle with the content of nano SiO2,the relationship between the frost resistance durability index and the effective porosity was analyzed,and the freeze-thaw damage mechanism of nano SiO2 concrete was studied.The research results show that:(1)The mass loss rate of nano SiO2 concrete decreases at the first and then increases with the increase of freeze-thaw cycle.(2)The relative elastic modulus of nano SiO2 concrete decreases with the increase of freeze-thaw cycle.(3)Adding nano SiO2 can effectively improve the frost resistance of concrete,and the optimal content of nano SiO2 is 4%.(4)The mechanism of freezing-thawing loss of nano SiO2 concrete is that the freezing-thawing cycle causes the change of internal pore structure of concrete,which leads to the decline of mechanical properties of concrete.
作者
胡青
HU Qing(Architecture Zabor University of Shaanxi Province,Xi'an 710068,China)
出处
《粉煤灰综合利用》
CAS
2020年第3期49-53,共5页
Fly Ash Comprehensive Utilization
基金
国家自然科学基金项目(51678379)。
关键词
纳米SIO2
混凝土
质量损失率
相对弹性模量
孔隙率
抗冻耐久性指数
nano SiO2
concrete
quality loss rate
relative modulus of elasticity
porosity
frost resistance durability index
