Influences of chloride immersion on zeta potential and chloride concentration index of cement-based materials

This paper measured the zeta potential and chloride concentration index of hardened cement paste, which was defined as the ratio of chloride concentration in the expressed pore solution to that in soaking solution. A model was proposed to explain the relationship of zeta potential and concentration index of hardened cement pastes immersed in chloride solution. The results showed that with the increase of chloride concentration in soaking solution, both the chloride concentration index and zeta potential of hardened cement paste gradually decreased. The addition of slag influenced the chloride concentration index and zeta potential. The relationship between chloride concentration index, chloride concentration in soaking solution and slag replacement level, as studied by the Gouy-Chapman model was well correlated with the measured results.