Effect of Nano-SiO2 on the Performance of Modified Cement-Based Materials

Abstract

With the advancement of science and technology, nano materials have been widely used in various fields. Nanomaterials have the advantages of small size and high activity. Since the 1990s, nanomaterials have been widely used in cement-based materials to make up for the deficiencies of traditional concrete construction materials. The purpose of this article is to study the impact of nano-materials on the specific properties of cement-based materials. Starting from the characteristics of nano-materials and combining the problems encountered in the practical application of cement-based materials, the water-absorbing properties, durability, and bonding properties of cement-based materials are respectively studied. Three aspects are analyzed. Firstly, the capillary water absorption theory was used for the experiment. The 3d water absorption of the conservation was tested through a comparative experiment. The order of descending water absorption was: NS @ PCE-3> NS @ PCE-2> NS @ PCE-1> NS, in this order, At 90 min, compared with the blank sample without surface treatment, the reduction in water absorption was 28.70%, 19.33%, 14.06%, and 3.91%, and similar conclusions were obtained for curing 7d and 28d. The results show that nano-silica is beneficial to Enhance the water absorption of cement-based materials. Secondly, the ASTMC1202 method was used to test the chloride ion flux of the cement mortar, and the hydrophilic nano-SiO2, lipophilic nano-SiO2, and nano-SiO2 sols were analyzed for 6 h of energization. At a state of 0.5%, the nano-SiO2 powder resisted mortar The permeability enhancement effect of the other two nanomaterials is obvious. The 6 h electric flux is only 1615.0, the nano-SiO2 sol effect is the second, the maximum doped electric flux is 1683.4 C, and the lipophilic SiO2 effect is the worst. Finally, the split-pull test and oblique shear test show that nano-SiO2 is beneficial for the adhesion of polymer cement-based materials. In summary, it is demonstrated that nano-SiO2 has a very good improvement effect on the water absorption, durability, and adhesion of cement-based materials.