Effect Of Glass Powder On Chloride Penetration And Reinforcement Potential Of Cement-based Material

Glass powder obtained from grinding waste glass by crushing is an excellent mineral admixture.Its utilization has huge environmental benefits and economic value.It has been used in alkali-aggregate reaction,sulfate corrosion,etc.But in chloride corrosion,the research is very limited.In this thesis,the influence of glass powder content and metakaolin was considered,and various microscopic monitoring methods were used to analyze the microscopic and mechanical properties evolution of glass powder cement-based materials before and after corrosion in chloride salt solution.Electrochemical methods were used to explore the effect of glass powder on reinforced concrete.The main contents and conclusions are as follows:（1）The Portland cement specimens with glass powder were cured to150 days and characterized before erosion,so as to compare and analyze the changes in solid-liquid phase composition after chloride erosion,and the influence of metakaolin was considered as well.Regardless of whether metakaolin is added or not,the results show that the pozzolanic reaction of glass powder can increase the content of Na⁺,SO₄^2-,Al（OH）₄^-,H₃Si O₄^-and reduce the content of Ca²⁺in the liquid phase of cement paste,the increase of Na⁺content significantly increases the alkalinity of pore solution.After glass powder is added to cement,the pore size becomes thinner and the capillary effect is enhanced,and the porosity of the cement-based material mixed with glass powder is lower than that of quartz powder.（2）The chloride ion migration and binding ability of glass powder cement specimens were detected by rapid electromigration test and electric flux test,XRD and TGA,and the micro and mechanical properties of glass powder cement specimens after chloride salt erosion were tested.The addition of glass powder can not improve the resistance to chloride ion penetration and chloride ion binding of cement-based materials.The chloride ion migration coefficient of the glass powder cement specimen is higher than that of the control group,and the chloride generation amount of the glass powder cement-based system and the glass powder-metakaolin cement-based system is lower.After immersing in sodium chloride solution,the alkalinity of the pore solution of the cement-based material mixed with glass powder is higher than that of the control group and remains at a high level.（3）The electrochemical impedance spectroscopy and potentiodynamic polarization curves were used for evaluating the corrosion resistant performances of coated samples.Tafel polarization curves and electrochemical impedance spectrum of the specimens were obtained.The results show that the content of glass powder and metakaolin have a positive influence on the corrosion resistance of reinforced concrete.From a physical point of view,the isolation effect of glass powder in the coating film is perfect,so that the coating can better isolate water vapor,electrolytes and other substances,from a chemical point of view,the incorporation of glass powder will increase the alkalinity of the pore solution,resulting in a relative decrease in the concentration ratio of chloride ions to hydroxide ions and at the same time chloride ions will react with monosulfate to form Friedel salts,thus preventing the corrosion of steel.39 Figures,10 Tables,74 References...