Calculation of chloride ion concentration in expressed pore solution of cement based materials exposed to a chloride salt solution
Abstract To investigate the relationship between the chloride ion concentration of the expressed pore solution C e and the exposure solution C es of cement based materials exposed to a chloride salt solution, a calculation of the C e based on an electrical double layer (EDL) model was proposed. The C e values were calculated using the proposed equations, applying the measured parameters: relative potential dps 0 dielectric constant e porosity P bulk density D volume percentage p i of pores with diameter d i The calculations explain why C e does not always equal to C es The results indicate that the expression method does not test the concentration of free chloride ions in the bulk solution C Cl b or the average concentration of the transportable chloride ions C ttr.a in the pores. However, the ratio C r of C e to C Cl b and the relationship between C e and C ttr.a can be calculated to more accurately measure chloride ion migration in cement based materials.