以实际工程项目为背景,用纳米SiO₂等量替换水泥制作混凝土试块,分别进行龄期为7、28、56d的立方体抗压强度试验、弹性变形试验、耐久性试验。采用线性回归的分析方法,对混凝土抗压强度试验数据进行分析,研究纳米SiO₂的掺入量与提高混凝土强度之间的数值关系,建立了以纳米SiO₂掺量为自变量,混凝土龄期分别是7、28、56d的抗压强度计算表达式。对弹性变形试验数据进行统计分析,研究不同纳米SiO₂的掺入量对混凝土各龄期弹性模量的改善和提高、纳米SiO₂对混凝土微观结构的改变、对抗渗标号和抗氯离子渗透能力的提高的影响,得出纳米SiO₂的最佳掺入量,指导纳米SiO₂混凝土的生产。

Based on the actual projects, tests of concrete cubic-compressive strength, tests of elastic modulus, and tests of durability involving the concrete which cement is replaced with the same amount of nano-SiO₂ making concrete blocks in the age periods of 7, 28, and 56 days are respectively conducted. The data is analyzed, and the numerical relationship between incorporation of nano-SiO₂ and concrete strength elevation is studied by using linear regression method. The calculation expression for the cubic-compressive strength of concrete with nano-SiO₂ content and concrete periods of 7, 28, and 56 days is established. The test data of elastic modulus is statistically analyzed, and the ways for improving and increasing of elastic modulus in different concrete ages with different contents of nano-SiO₂, the effects of nano-SiO₂ on the change of concrete microstructure and on the increase of anti-penetration grade and chloride-penetration resistance are explored. The best mixing amount of nano-SiO₂ is obtained in order to guide the production of concrete contained nano-SiO₂.