Research On Corrosion Of Steel Fiber Unpurified Sea Sand Concrete Based On Image Processing

According to《Mineral Resources Law of the people’s Republic of China》and other relevant laws and regulations,China has completely banned river sand mining since 2018,making people have to pay attention to the rich sea sand.Compared with river sand,sea sand has its unique advantages,such as low cost and good grain shape.Because sea sand is rich in chloride ion,the sea sand used in our country is purifying sea sand at present.However,washing sea sand not only wastes water resources,but also consumes money and energy,which leads to many unqualified purified sea sand flowing into the market and affecting the durability of concrete.There are even many "sea sand houses" in some coastal areas,seriously threatening the lives of the people and the national economy.In the early days,unpurified sea sand was used in Japan,South Korea and other countries.This paper mainly studies the internal corrosion of steel fiber unpurified sea sand concrete.Firstly,the single factor mechanical test and orthogonal test were carried out to determine the best mix ratio,and then the chloride ion migration coefficient method was used to study the chloride resistance of steel fiber reinforced sea sand concrete.Finally,based on the background correction and binarization in the image processing technology,the microscopic image of sea sand concrete is studied and analyzed by using Image-Pro Plus software,and combined with the principle of statistics,the correlation between the two-dimensional width information of corrosion and the chloride ion migration coefficient of the corresponding specimen is analyzed.The experimental results are as follows:1.When the content of fly ash is 20%,the amount of rust inhibitor is 2.0%,and the volume ratio of steel fiber is 1.0%,it is the optimal mix ratio.The compressive performance of concrete is 18.5% higher than that of ordinary concrete,and the splitting tensile performance is 31.5% higher than that of ordinary concrete.2.The chloride ion resistance of sea sand concrete with rust inhibitor is better than that of non-concrete.Among them,the chloride ion transfer coefficient of the blank group is 5.17×10-12m2/s,the chloride ion transfer coefficient of the non-rust inhibitor sample is 6.24×10-12m2/s,and the change rate is 20.6%.The chloride ion transfer coefficient of the rust inhibitor sample is 4.73×10-12m2/s,and the coefficient change rate is-8.5%.3.Based on the image processing technology,the microscopic images are analyzed by Image-Pro Plus software.The results show that the two-dimensional average width of corrosion layer of No.① concrete mixed with sea sand is 2.278 ?m,which is 53.67% less than that of No.③ ordinary steel fiber reinforced concrete;The two-dimensional average width of the corrosion layer of No.② unmixed sea sand steel fiber reinforced concrete is 6.033?m,which is 22.70% higher than that of No.③concrete.4.According to the principle of statistics,the correlation between the two-dimensional average width information of corrosion and the chloride ion migration coefficient of the corresponding specimen is analyzed,and the correlation coefficient is ρ_xy=0.893,which shows that there is a high linear positive correlation between them.