Research On The Superhydrophobic Silicon-Based Coatings For Concrete Corrosion Resistance

This paper research initially on the hydrophobic coating which have better protective effect on concrete’s salt corrosion.Observe microstructure of the coating.Test characterize the structure and application performance.Tests application performance and characterize the structure.It provides the basis for theoretical analysis,to lay the foundation for the practical application of the coating.Super-hydrophobic effect is the coalition of double sodium micro roughness and low surface energy.This study construct micron roughness at first.On this basis construct nanoscale roughness.Finally,brush the mixture of silane reduce its surface energy as modification layer.Using micron layer structure,nano-structure layer and low surface energy modification coating prepare coating meet the superhydrophobic conditions.Selecte the method of spraying silica sol and Ca(OH)2 respectively to constructe micron structure layer obtaining micron rough surface whoes particle size is 10 ~ 20μm and evenly distributed after trying method of diluting silica sol,dispersing silica sol,and so on.Its products were Microstructural analysis by infrared spectroscopy(FTIR)and X-ray diffraction analyzer(XRD).Its prime substances is semicrystalline state of a calcium silicate hydrate(0.8~1.5CaO·SiO2·nH2O)and the remaining Ca(OH)2.Then construct nanoscale structural layer.TEOS,EtOH,NH3·H2O and hexadecyl trimethoxysilane as raw material for preparing the new sol.Observed dried sample with AFM,the shape is more dense uniform particulate of size is 200~300nm.Try to form nano micro roughness through cover it as nanoscale roughness on the first layer of micron coating.After painting this particle size nanoscale sol a second coating layer,morphology observed by SEM is 1~2μm granular particles,integrally formed a topographical features of “large particles wrapped in small particles”.Low surface energy modification layer is formed by mixing hexadecyl trimethoxy silane,ethyl alcohol,stearic acid and trimethylsilyl chloride.Finally reduce the coating’s surface energy.Thereby the final coating surface morphology similar to the super-hydrophobic surface.Test the mean surface contact angle value reached 132.1 °Finally,test the coating concrete block’s sulfate corrosion resistance.The test results show that corrosion coefficient of concrete coated with complete coating is 94.46%.played a protective role on concrete anti-sulfate corrosion.But the adhesion between the coating and the concrete is poor.