The Research of Influence on the Freezing Resistance and the Permeation Resistance of Concrete With Spraying Silane

Silane, as an extremely hydrophobic material, changes concrete surface from hydrophilic state to hydrophobic state by spraying on the surface of concrete. It has the ability to block the external corrosive medium to improve the durability of concrete. Three types of strength grade of concrete (C30, C40, C50) were designed, after spraying with silane on the surface of concrete, to measure the penetration depth of silane and the influence on water-absorption rate, liquid-absorption rate, chloride ion diffusion coefficient and salt frost resistance. The test result shows that: by spraying silane on the surface of concrete,the one hour water-absorption rate of concrete was reduced by more than 98%, the 48 hours water-absorption rate was cut down above 91%, and the 48 hours liquid-absorption (3% NaCl solution) rate was decreased above 94%. The penetration depth for C30 and C50 has the maximum value (6.3mm) and minimum value (3.9mm) respectively. Absorption reduction rate of chloride ion overall was decreased by above 93%, and chloride ion diffusion coefficient was reduced by 42% ~ 48%. The freeze-thaw resistance was improved by 5 times. Key words: silane, the salt frost resistance, liquid-absorption rate, chloride ion diffusion coefficient