| Chloride ion erosion is one of the most common reasons for the failure of concrete structures,so how to prevent the corrosion of concrete structures by chloride ion and how to ensure the service life of the structure has become an important issue in the field of architecture.This paper chose the organic film coated concrete as the research object,through the research of the resistance to chloride penetration and microscopic test of different coating system with different water cement ratio of concrete after different aging conditions to get the law between the resistance to chloride penetration at different aging stages and macroscopic and microscopic properties degeneration of coatings.And establish the service prediction model of organic film based on nature climate and coastal climate conditions.The main research results are as follows:1?Based on the experimental study on the electric flux of the coating concrete before aging,the protective ability of different coating systems was obtained.Paint finish:Polyurethane > epoxy resin > chlorinated rubber.With system brushing: polyurethane >chlorinated rubber > epoxy resin.Increasing the thickness of brushing system can improve the corrosion resistance of the coating concrete.Considering the cost,the best coating system is a primer+polyurethane finish.The influence of concrete diffusion performance should be taken into account when organic film is used to improve the durability of concrete.2?Based on the experimental study on the electric flux of the aged coating concrete,it is found that the electric flux of concrete increases with UV aging time,and the electric flux of concrete decreases exponentially with the increase of thickness of epoxy coating system.Under the condition of natural aging and seaside exposure,the protective effect of various coatings on concrete is as follows: polyurethane > chlorinated rubber > epoxy resin.As a method of laboratory accelerated test to determine the resistance of concrete to chloride ion penetration,the electric flux has a good correspondence with the actual experiment.It can reflect the true protective effect of coating on concrete.3?Based on the experimental data,the relationship between the electric flux and the aging time is analyzed,and the service life of the coating is predicted.Compared with natural aging,the average acceleration effect of UV aging is about 13.31 times,and the average acceleration effect of seaside exposure is about 1.667 times.The analysis of the coating before and after aging degree of macro changes and micro morphology showed that the anti chloride ion protection ability of organic film coating with attenuation of coating aging is caused by the degradation of coating corrosion and development defects.4?According to the service life of the coating and the cost of the coating system,the average annual cost of each coating system is obtained.The average annual cost of the primer+intermediate+2times polyurethane coating system is the lowest,so when the labor cost is not considered,this brushing system is the most economical one. |
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