Resistance to chloride ion permeability of concrete mixed with fly ash, slag powder, and silica fume

Abstract

This paper attempts to study the resistance to chloride ion permeability of concrete mixed with different admixtures such as fly ash (FA), slag powder (SP), and silica fume (SF). For this, taking the C50 concrete with the 1:1 proportion of FA and SP, the test method for rapid chloride ion migration (RCM) coefficients was used to study the resistance to chloride ion permeability and economic benefits of the concrete under the conditions of different total amount of admixtures, SF content, and air content. The results show that the increase in the total amount of the admixture can improve the concrete resistance to chloride ion penetration, but in a gradually weakening trend; the increase in SF content can increase the concrete resistance to chloride ion penetration, but the enhancement effect is gradually decreased; the SF has more significant effect on improving the 56d concrete resistance to chloride ion penetration; the increase of air content greatly increases the chloride ion migration coefficient of concrete at 28d, and the chloride ion migration coefficient increases linearly at 56d; the air content within 5% has an insignificant effect on the resistance to the chloride ion permeability; the NH40-2 was chosen to be the optimal mix ratio.