| With the continuous development of water resources,the 172 major water conservancy projects that have been planned in recent years are mainly concentrated in the central and western regions.And gradually move to the higher and colder regions of the water rich west.Water workers in the area often face a more complex and demanding service environment(such as high altitude,high temperature difference,uv irradiation,and freezing and melting cycles).Among them,freeze-thaw and ultraviolet irradiation are the most representative influencing factors for the deterioration of concrete structures.Therefore,developed a waterproof,good weatherability and efficient lasting hydraulic concrete protective coating on the surface of the concrete structure from erosion or slow down the environmental factors,will help to improve the durability of hydraulic structures in western high altitude areas and security,improving the quality of our water conservancy project construction and operation maintenance level.Fluorocarbon coating has become one of the effective means of surface protection due to the advantages of excellent low surface energy,medium corrosion resistance and weatherability.However,this kind of coating used in hydraulic concrete surface protection,durability is still face the shortage of bond properties,table interface limited technical problems,such as limits its widespread use.By analyzing the composition of coating and the impact of coating process on the properties of surface and interface,designing and preparation of the fluorine carbon nanotubes composite coating composed of double coating system which is make up of "nano-silica,fluorocarbon coating and fluorine silane surface coating".Coated the homemade room-temperature type of fluorine carbon/nano silicon dioxide in the surface of cement mortar.And then coating perfluorinated octyl triethoxy silane on the surface after waiting for the composite coating is dry.In this article,through ultraviolet aging test,freeze-thaw cycling test,freezing and thawing-uv alternate cycling test and water resistance test,and uses the fourier transform infrared spectrum,scanning electron microscopy(sem)and contact angle test,test means such as drawing test to study the coating material itself and the durability of the coating/mortar system.The results show,The addition of nano-SiO2 particles can improve the anti-ultraviolet aging performance of coating/mortar specimens,anti-freeze and melt cycle performance and anti-freeze and ultra-violet alternating cycle performance.When the content of nano-SiO2 particles is 10%,the coating/mortar surface durability is best,and the interface adheres to the durable performance.Combining the results of the microscopic representation of the fourier transform infrared spectroscopy,scanning electron microscopy,and the study of durability.The aging rules and mechanism of coating body and coating/mortar system were summarized.Preliminary,the main reason for the aging of the coating ontology is that in the process of photoaging,the ester bond in fluorocarbon is liable to rupture,resulting in the degradation of the anti-ultraviolet aging.Coating/mortar interface in the process of aging,long time of uv irradiation making it easier for the coating of crosslinking reaction,make the combination of coating molecules and mortar matrix between more closely.But after ultraviolet aging reaches a certain time,continuous high temperature ultraviolet radiation coating with cement mortar interface compatibility,bonding strength between coating and mortar decreased. |
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