Effects of metakaolin on the mechanical and anticorrosion properties of epoxy emulsion cement mortar

Abstract Different sizes of Metakaolin (MK) were introduced into epoxy resin emulsion concrete mortar (EECM) to improve mechanical and anticorrosion properties. The effects of MK contents and sizes on the mechanical property, water absorption and chloride diffusion coefficient of EECM were studied respectively. Electrochemical tests were used to measure corrosion rate of samples. The results showed MK could greatly enhance the mechanical properties of EECM and more content MK obtained higher strength. The smaller size MK caused a slight decrease in strength due to poor dispersion in EECM. The water absorption and chloride diffusion coefficient of EECM both decreased significantly after adding MK. The smaller size of MK with 400-mesh and 1250-mesh made the water absorption reduced approximately 51%. The chloride diffusion coefficient of EECM also reduced with the increasing of MK content, especially the largest decline 73.1% corresponds to 1250-mesh MK. The data in polarization curves and EIS curves coincide with the above conclusion. The larger size of MK had the better anticorrosion effect on steel bar than that with smaller size. The corrosion situation on the surface of steel bars in mortar supplied the realistic anticorrosion effect.